Most problems with a replacement engine happen in the first hour. An engine started without oil pressure, with the wrong coding or with a contaminated intake can be damaged before it has done a kilometre.
This guide gives the complete procedure we recommend for every used engine we sell: before fitting, the first start, coding, and the first 1,000 km.
Before the engine goes in
Compare the replacement engine with your old one, part by part. Transfer sensors, brackets and ancillaries that differ, and replace the parts that are cheap now and expensive later: rear main seal, clutch or torque converter seal, water pump, thermostat, belts and mounts.
Inspect the intake for debris and the turbo inlet for damage. Fit new oil and coolant of the right specification, and a new oil filter.
The first start
Prime the oil system by cranking with the fuel pump and ignition disabled until oil pressure builds. Check for leaks, then start the engine and let it idle while watching oil pressure, coolant temperature and fault codes.
Bleed the cooling system carefully, especially on engines with electric water pumps that need a diagnostic routine.
Coding and adaptations
Modern BMWs need the engine ECU to be matched to the car's immobiliser. Injector correction codes, the battery registration and adaptation resets must be done with diagnostic software.
The full fitting procedure
- Compare the engines side by side. Put the replacement next to the old engine and compare sensors, brackets, connectors, the sump, the starter and the flywheel or flexplate. Note anything that must be transferred.
- Transfer the parts that differ. Move the parts that are specific to your car, such as the engine harness on some models, the sump on xDrive cars or the air conditioning compressor bracket. Use new seals and gaskets for everything you move.
- Replace the rear main seal and drive parts. With the engine out, the rear crankshaft seal is easy to reach. Fit a new one, inspect the flywheel and clutch on manual cars or the converter seal on automatics.
- Renew the cooling system. Most engine failures start with cooling. Fit a new water pump, thermostat and hoses, check the radiator and fan, and use the correct coolant.
- Fit new engine mounts. Old mounts transfer vibration and can let the engine move enough to damage hoses. They are cheap and easy to replace with the engine out.
- Inspect or replace the timing chain parts. Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
- Replace the rear timing chain if in doubt. On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting.
- Fit a new timing belt kit. Fit a new belt, tensioner and water pump and set the timing with the correct tools before the first start.
- Prepare the turbo. Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting.
- Code the injectors and bleed the fuel. Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry.
- Check the particulate filter. If the old engine failed with oil or coolant entering the exhaust, the DPF may be contaminated. Check its back-pressure before relying on it.
- Clean the intake. If the old engine failed internally, debris can be in the intake or intercooler. Clean them so nothing reaches the new engine.
- Fill with the right oil and prime it. Fill with new oil of the correct specification and a new filter. Crank with the fuel and ignition disabled until oil pressure builds.
- Coding and adaptations. On modern BMWs, the engine ECU must be matched to the car's immobiliser (CAS, FEM or BDC). Reset adaptations, register the battery and clear faults with diagnostic software.
- Reset VANOS adaptations. Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
- Teach the Valvetronic limit stops. Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
- First start and leak check. Start the engine, let it idle and watch oil pressure, temperature and fault codes. Check for leaks and bleed the cooling system.
- First 1,000 km. Drive gently for the first few hundred kilometres, vary the engine speed and avoid full load. Change the oil and filter after about 1,000 km to remove any assembly debris.
Engine-specific notes
M10
Oil: A good 15W-40 or 20W-50 mineral or semi-synthetic oil with zinc protection for flat-tappet cams, about 4.0 to 4.5 litres with filter. Timing: Single-row or duplex timing chain on the front of the engine; no scheduled change, inspect guides when the head is off.
Valve clearance is adjusted cold with eccentric adjusters on the rocker arms. Fit a new spray bar if the old one is blocked or loose.
Check before the first start:
- Camshaft and rocker wear — Remove the rocker cover and look at the lobes and rocker faces for pitting or a polished flat.
- Timing chain guides and tensioner — Listen at the front cover during the first seconds after a cold start.
- Warped head after overheating — Ask for a compression or leak-down test and check the coolant for oil.
- Valve stem seals — Watch the exhaust for the first ten seconds after a cold start.
- Oil leaks from age — Look under the bellhousing and around the front cover for fresh oil.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M20
Oil: 10W-40 or 15W-40 semi-synthetic, about 4.25 litres with filter. Timing: Rubber timing belt with tensioner, changed with the water pump every 60,000 km or four years.
Valve clearance is set cold at about 0.25 mm with eccentric adjusters. Use a new head bolt set whenever the head comes off.
Check before the first start:
- Timing belt failure — Ask for the date of the last belt and tensioner change. If there is no record, treat it as due.
- Cylinder head cracks — Pressure-test the cooling system and look for cracks when the cam cover is off.
- Rocker arm and shaft wear — Inspect rockers and clips with the cam cover removed.
- Oil spray bar and cam wear — Check the spray bar banjo bolts are tight and the holes clear.
- Water pump and thermostat — Look for coolant trails below the pump and on the belt cover.
Extra steps for this engine: Fit a new timing belt kit: Fit a new belt, tensioner and water pump and set the timing with the correct tools before the first start.
M30
Oil: 10W-40 or 15W-40, about 5.75 litres with filter on most versions. Timing: Duplex timing chain at the front with a hydraulic tensioner; no service interval.
Valve clearances are set with eccentric adjusters at about 0.30 mm cold. Keep the cooling system fresh and the fan clutch healthy.
Check before the first start:
- Head gasket and cracked heads — Do a compression test and look for bubbles in the expansion tank with the engine running.
- Cooling system age — Check the fan clutch resistance hot and the radiator for blocked cores.
- Rocker arm wear — Inspect the cam surface with the valve cover off.
- Timing chain tensioner — Listen for a cold-start rattle at the front of the engine.
- Oil pressure sender and leaks — Check for oil around the filter housing and the bellhousing.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M40
Oil: 10W-40 semi-synthetic, about 4.0 litres with filter. Timing: Rubber timing belt with tensioner, changed on time.
Because cam wear is common, a new camshaft and rockers are a sensible addition when a used M40 is fitted.
Check before the first start:
- Timing belt — Look for a dated belt sticker or invoice.
- Camshaft lobe wear — Remove the cam cover and inspect the lobes.
- Rocker arms — Listen at idle with the oil hot.
- Cooling and thermostat — Check the hoses for swelling and the radiator tanks for cracks.
Extra steps for this engine: Fit a new timing belt kit: Fit a new belt, tensioner and water pump and set the timing with the correct tools before the first start.
M42 and M44
Oil: 10W-40 or 5W-40 synthetic, about 4.5 litres with filter. Timing: Timing chain at the front with guides and a hydraulic tensioner.
Hydraulic lifters mean no valve adjustment, but they need clean oil of the right viscosity to stay quiet.
Check before the first start:
- Head gasket — Check for mayonnaise under the oil cap and for coolant loss without visible leaks.
- Timing chain guides and tensioner — Listen at the front of the engine on a cold start.
- Valve cover and oil leaks — Pull a coil or plug lead and look for oil.
- Plastic cooling parts — Look for white coolant stains and check the water pump impeller type.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M43
Oil: 5W-40 or 10W-40 synthetic, about 4.25 litres with filter. Timing: Single-row timing chain with a plastic guide rail and hydraulic tensioner.
Replace the guide rail, tensioner and valve cover gasket before fitting a used M43. It is a small job with the engine out.
Check before the first start:
- Timing chain guide rail — Remove the valve cover and inspect the top of the guide; replace it when fitting any used M43.
- Valve cover gasket leaks — Look for burnt oil on the exhaust side.
- Ticking hydraulic lifters — Listen after the engine has warmed; noise that stays is a lifter problem.
- Engine mounts and vibration — Check mounts for split rubber when the engine is in the car.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M50
Oil: 5W-40 or 10W-40 synthetic, about 6.5 litres with filter. Timing: Duplex lower chain and single upper chain at the front with hydraulic tensioner.
Hydraulic lifters, no valve adjustment. Refresh VANOS seals when fitting a used M50TU.
Check before the first start:
- Cooling system — Check for a metal impeller water pump and a recent expansion tank.
- VANOS seals (M50TU) — Listen for a rattle at the front of the head at idle and check for a flat spot below 3,000 rpm.
- Crankcase ventilation valve — Check for oil in the intake boot and around the dipstick tube.
- Oil filter housing gasket — Look for oil on the alternator side of the engine.
- Valve cover gasket — Remove a coil and inspect the well.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
M52
Oil: 5W-30 or 5W-40 synthetic to BMW Longlife standard, about 6.5 litres with filter. Timing: Duplex lower and single upper chains at the front with hydraulic tensioner.
Ask whether the block is Nikasil or Alusil. Engines built from late 1998 use Alusil.
Check before the first start:
- Nikasil bore wear — A compression or leak-down test is the only reliable check; Alusil and iron-block units are not affected.
- Cooling system — Look at the date of the last cooling refresh and check for a metal impeller.
- VANOS seals and solenoids — Listen for a diesel-like rattle at idle and check for torque loss low down.
- DISA valve (M52TU) — Remove the DISA valve and check the flap pin for play.
- Crankcase ventilation — Look for oil in the intake and smoke on start.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
M54
Oil: 5W-30 BMW Longlife-01 synthetic, about 6.5 litres with filter. Timing: Duplex and single chains at the front, no scheduled replacement.
Change the CCV system and DISA valve before fitting a used M54. Both are cheap compared with an engine.
Check before the first start:
- Crankcase ventilation (CCV) — Pull the dipstick at idle: strong suction or a whistle points to the CCV.
- DISA valve flap — Remove the valve and check for play in the flap.
- Cooling system — Look for white coolant stains and check the impeller.
- Oil filter housing and valve cover gaskets — Look at the exhaust side and down the front of the block.
- Oil consumption from piston rings — Ask for consumption figures; a compression test is useful.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
S14
Oil: 10W-60 or 15W-50 synthetic is typical, about 4.5 litres. Timing: Timing chain driving both camshafts.
Keep the engine number and documentation together; matching numbers add value on an E30 M3.
Check before the first start:
- Valve clearances — Ask for the last clearance check and a leak-down test.
- Timing chain and guides — Inspect guides and listen for a cold-start rattle.
- Throttle body linkage — Check for free play and even opening across the four throttles.
- Bearing wear on track engines — Look at the oil analysis or open the sump on unknown engines.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M88 and S38
Oil: 10W-60 synthetic is common, about 5.8 litres. Timing: Duplex timing chain with hydraulic tensioner.
The 3.8 litre S38B38 uses a dual-mass flywheel; check its condition when buying a complete unit.
Check before the first start:
- Valve clearances — Ask for the last clearance check.
- Timing chain guides — Listen for start-up rattle at the front.
- Oil pump drive nut — Ask if the oil pump nut has been secured.
- Throttle bodies and sensors — Check for smooth idle and even cylinder balance.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
S50 and S52
Oil: 10W-60 synthetic is common for S50 engines; 5W-30 Longlife for S52, about 5.5 to 6.5 litres. Timing: Duplex and single timing chains at the front.
Fit a new oil pump nut and safety wire when the sump is off.
Check before the first start:
- Oil pump nut — Ask whether the oil pump nut has been secured.
- VANOS (S50B32) — Listen for rattle at idle and check for fault codes.
- Cooling system — Look for a recent cooling refresh.
- Valve cover and oil leaks — Check the front of the head for oil.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
S54
Oil: 10W-60 synthetic as BMW specifies, about 5.5 litres. Timing: Duplex chain at the front driving both camshafts.
Fit new rod bearings and upgraded VANOS parts when installing a used S54. It is easier with the engine out.
Check before the first start:
- Rod bearings — Ask when the rod bearings were last replaced; an oil analysis helps.
- VANOS unit — Check for VANOS codes and ask about upgraded bolts and pump disc.
- Valve clearances — Ask for the last adjustment.
- Throttle actuator — Check for throttle fault codes.
- Oil consumption — Ask for the consumption log.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
N42 and N46
Oil: 5W-30 BMW Longlife-01 or Longlife-04, about 4.25 litres. Timing: Timing chain at the front with balance shafts.
Replace the timing chain, tensioner and valve stem seals when fitting a high-mileage used N46.
Check before the first start:
- Oil consumption — Ask for consumption figures and check the spark plugs for oil fouling.
- Timing chain stretch — Listen for a rattle on a cold start and check the camshaft timing values.
- Valvetronic motor and eccentric shaft sensor — Check for Valvetronic fault codes.
- Vacuum pump and oil leaks — Look at the back of the head.
- Crankcase ventilation — Check for a whistle at idle.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
N43
Oil: 5W-30 BMW Longlife-01 or Longlife-04, about 4.25 litres. Timing: Timing chain at the front.
Use good-quality, low-sulphur petrol. Fit new coils and plugs to a used N43 before first start.
Check before the first start:
- Piezo injectors — Check misfire counters and injector correction values.
- Ignition coils and spark plugs — Read the misfire history and inspect the plugs.
- NOx sensor and catalyst — Check for NOx sensor fault codes.
- Timing chain — Listen at cold start.
- Vacuum pump and oil leaks — Look at the back of the head.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
N13
Oil: 5W-30 BMW Longlife-01, about 4.25 litres. Timing: Timing chain at the front.
Change the chain and tensioner when buying a high-mileage unit.
Check before the first start:
- Timing chain stretch — Listen on a cold start and check timing values.
- Carbon build-up — Inspect the intake valves with a borescope.
- High-pressure fuel pump — Check fuel pressure fault codes.
- Turbo wastegate — Listen for a rattle when lifting off.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
N20 and N26
Oil: 0W-30 or 5W-30 BMW Longlife-01, about 5.25 litres. Timing: Timing chain at the rear (gearbox end).
Replacing the chain on an N20 normally needs the engine out, so a used unit is the time to do it.
Check before the first start:
- Timing chain guide — Listen for a whine or rattle; ask if the updated guides and chain are fitted.
- Oil pump drive chain — Check oil pressure warnings.
- Electric water pump — Check for cooling fault codes.
- Oil filter housing and valve cover gaskets — Look at the exhaust side for oil.
- Carbon build-up — Borescope inspection.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
N52
Oil: 5W-30 BMW Longlife-01 or 04, about 6.5 litres. Timing: Timing chain at the front.
Fit a new water pump and thermostat with any used N52; they are on the outside and cheap compared with labour later.
Check before the first start:
- Hydraulic lifter tick — Listen on a cold start; a tick that fades is normal-ish.
- Electric water pump and thermostat — Check for cooling codes and service history.
- Valve cover gasket and eccentric shaft sensor — Look for oil on the exhaust side.
- Oil filter housing gasket — Check below the filter housing.
- VANOS solenoids — Read the VANOS adaption values.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
N53
Oil: 5W-30 BMW Longlife-01 or 04, about 6.5 litres. Timing: Timing chain at the front.
Use high-quality low-sulphur petrol and fit new coils and plugs when installing a used unit.
Check before the first start:
- Piezo injectors — Check misfire counters and injector corrections.
- Ignition coils — Read misfire history.
- NOx sensor and catalyst — Check NOx fault codes.
- High-pressure fuel pump — Check fuel pressure codes.
- Electric water pump — Ask when it was replaced.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
N54
Oil: 5W-30 BMW Longlife-01, about 6.5 litres. Timing: Timing chain at the front.
Fit new plugs, check injectors and confirm the HPFP revision before installing.
Check before the first start:
- High-pressure fuel pump — Check the part number and for fuel pressure codes.
- Wastegate rattle — Listen when lifting off throttle and check for oil smoke.
- Piezo injectors — Check the injector index revisions.
- Electric water pump — Ask when it was replaced.
- Charge pipe and oil leaks — Look for oil and listen for boost leaks.
- Carbon build-up — Borescope inspection.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
N55
Oil: 5W-30 or 0W-30 BMW Longlife-01, about 6.5 litres. Timing: Timing chain at the front.
Replace the oil filter housing gasket and valve cover gasket before installing a used N55.
Check before the first start:
- Oil filter housing gasket — Look below the filter housing.
- Valve cover gasket — Look for oil on the exhaust side.
- Electric water pump and thermostat — Check cooling codes.
- Charge pipe — Listen for boost leaks.
- Wastegate rattle — Listen when lifting off.
- Oil pan gasket — Check underneath.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
S55
Oil: 0W-30 or 5W-30 BMW Longlife-01, about 6.5 litres. Timing: Timing chain at the front.
Fit a crank hub upgrade if the engine will be tuned.
Check before the first start:
- Crank hub — Ask whether the crank hub has been upgraded.
- Charge pipe — Check for boost leaks.
- Oil leaks — Look for oil around the head.
- Cooling — Check for coolant loss.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
S58
Oil: 0W-30 or 5W-30 BMW Longlife-01, about 6.75 litres. Timing: Timing chain at the rear.
Confirm the donor car's accident damage did not affect the engine.
Check before the first start:
- Limited service history — Ask for the donor car's mileage and service record.
- Oil leaks — Check the head and filter housing.
- Cooling — Pressure-test the cooling system.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
B38
Oil: 0W-20 or 0W-30 BMW Longlife-17 FE+ or 01, about 4.25 litres. Timing: Timing chain at the rear (gearbox end).
Front-drive (B38A) and rear-drive (B38B) versions are not interchangeable without changes.
Check before the first start:
- Coolant leaks — Check for coolant loss.
- Ignition coils — Read misfire counters.
- Engine mounts — Check mounts in the car.
- Carbon build-up — Borescope inspection.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
B48 and B46
Oil: 0W-20 or 0W-30 BMW Longlife-17 FE+ or 01, about 5.25 litres. Timing: Timing chain at the rear (gearbox end).
Check front-drive (B48A) or rear-drive (B48B) before ordering.
Check before the first start:
- Coolant leaks — Check for coolant loss.
- Oil filter housing gasket — Check the filter housing.
- PCV and valve cover — Look for oil on the head.
- Water pump — Check for coolant trails.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
B58
Oil: 0W-30 BMW Longlife-01 or 17 FE+, about 6.5 litres. Timing: Timing chain at the rear (gearbox end).
Check the version (B58B30M0, M1 or TU) before ordering.
Check before the first start:
- Coolant leaks — Check for coolant loss.
- Oil filter housing — Check below the housing.
- PCV valve — Look for oil in the intake.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
M60
Oil: 5W-40 or 10W-40 fully synthetic, about 7.5 litres with filter. Timing: Duplex timing chains at the front, one per bank, with hydraulic tensioners.
Ask for a compression test before purchase. Replace the valley coolant pipes and water pump while the engine is out.
Check before the first start:
- Nikasil bore damage — A cold and hot compression test or a leak-down test on all eight cylinders is the only reliable check.
- Timing chain guides and tensioners — Listen for a rattle on a cold start, especially from the front of either bank.
- Coolant leaks in the valley — Look at the back of the engine for coolant trails and pressure-test the system.
- Valve cover and spark plug tube gaskets — Pull a coil and check the well for oil.
- Engine wiring harness — Flex the harness gently and look for cracked insulation near the heads.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M62
Oil: 5W-30 or 5W-40 fully synthetic, about 7.5 litres with filter. Timing: Single-row timing chains, one per bank, with plastic guides and hydraulic tensioners.
A timing guide kit, valley pipe O-rings and valve cover gaskets are the standard parts to fit with a used M62.
Check before the first start:
- Timing chain guides — Remove the valve covers and inspect the upper guides; replace all guides when fitting a used engine.
- Valve stem seals — Watch the exhaust after a cold start and after a long idle.
- Valley coolant pipe — Look for coolant at the back of the engine and pressure-test the system.
- Water pump and thermostat — Look for coolant trails at the front of the engine.
- VANOS (M62TU) — Read the VANOS fault memory.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
N62
Oil: 5W-30 BMW Longlife-01, about 8 litres with filter. Timing: Timing chains at the front, one per bank, with guides and tensioners.
Fit new valve stem seals, the alternator bracket gasket and valve cover gaskets with a used N62 if they have not been done. Access is far easier with the engine out.
Check before the first start:
- Valve stem seals — Watch the exhaust after a long idle; heavy smoke on the first press of the throttle is typical.
- Alternator bracket gasket — Look for oil at the back of the valley.
- Valve cover gaskets — Look for burnt oil on the manifolds.
- Valvetronic motors and eccentric shaft sensors — Read the fault memory for Valvetronic codes.
- Coolant transfer pipe — Pressure-test the cooling system.
- Timing chain guides — Listen for rattle on a cold start.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine. Teach the Valvetronic limit stops: Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
N63
Oil: 5W-30 BMW Longlife-01, about 8.5 litres with filter. Timing: Timing chains at the front, one per bank.
Prefer N63TU and later engines where the car allows it. Check the version letter on the engine code (B44A, B44B, B44C, B44D) before ordering.
Check before the first start:
- Oil consumption from valve stem seals — Ask for oil consumption figures and check whether the seals have been replaced.
- Piezo injectors (early N63) — Read misfire counters and check injector revisions.
- Timing chain stretch — Read the camshaft timing values and listen at cold start.
- Turbo coolant and oil lines — Look for coolant loss and oil smoke.
- Crankcase ventilation — Check for smoke and oil in the intake.
- Battery drain — Check that the cooling pump after-run works.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
S62
Oil: 10W-60 BMW M synthetic, about 8 litres. Timing: Timing chains, one per bank, with guides and tensioners.
Ask for service history and any timing guide work. Matching engine numbers matter to Z8 and M5 buyers.
Check before the first start:
- Timing chain guides — Inspect guides with the valve covers off and listen for start-up rattle.
- VANOS — Read VANOS fault codes and listen at idle.
- Rod bearings — Oil analysis or inspection with the sump off.
- Throttle actuator — Check for throttle fault codes.
- Cooling — Pressure-test the system.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
S63
Oil: 0W-30 or 5W-30 BMW Longlife-01, about 9 litres. Timing: Timing chains, one per bank.
Prefer later S63TU and T4 engines. Check the version code before ordering.
Check before the first start:
- Rod bearings — Oil analysis and service history; many owners replace bearings preventively.
- Injectors — Read misfire counters and injector corrections.
- Turbochargers — Look for blue smoke and check shaft play.
- Valve stem seals — Ask for consumption figures.
- Timing chain — Check camshaft timing values.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
S65
Oil: 10W-60 BMW M synthetic, about 8.8 litres. Timing: Timing chains, one per bank.
Fit new rod bearings when fitting a used S65 unless they were recently replaced.
Check before the first start:
- Rod bearings — Ask for the bearing replacement date and use oil analysis.
- Throttle actuators — Read throttle fault codes.
- Idle control valve — Check for idle faults.
- Oil leaks — Check below the sump and around the heads.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
S68
Oil: 0W-30 BMW Longlife-01 or 17 FE+. Timing: Timing chains.
Confirm compatibility with the hybrid system before ordering.
Check before the first start:
- Limited history — Ask for the donor car's mileage and accident report.
- Accident damage — Inspect the front of the engine and the wiring harness.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting.
S85
Oil: 10W-60 BMW M synthetic, about 9.25 litres. Timing: Timing chains, one per bank.
Fit new rod bearings when fitting a used S85 unless they were recently replaced.
Check before the first start:
- Rod bearings — Ask for the bearing replacement date and use oil analysis.
- Throttle actuators — Read throttle fault codes.
- High-pressure VANOS — Read VANOS fault codes.
- Oil leaks — Check below the sump and around the heads.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Reset VANOS adaptations: Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
M70 and M73
Oil: 5W-40 or 10W-40 synthetic, about 7.5 litres. Timing: Single-row timing chains, one per bank.
Keep the cooling system fresh. Check both ECUs before purchase.
Check before the first start:
- Wiring harness — Inspect the harness near the heads.
- Cooling — Pressure-test the system.
- Dual engine management — Read both ECUs for fault codes.
- Fuel system — Check fuel pressure.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
N73 and N74
Oil: 5W-30 BMW Longlife-01. Timing: Timing chains, one per bank.
Check whether the engine is BMW or Rolls-Royce specification before ordering.
Check before the first start:
- Ignition coils and spark plugs — Read misfire counters.
- Injectors — Read injector corrections.
- Coolant leaks — Pressure-test the system.
- Turbo oil lines (N74) — Look for oil smoke.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M21 and M41
Oil: 10W-40 or 15W-40 diesel-rated oil. Timing: Timing belt on the M21, chain on the M41.
Change the M21 timing belt when fitting a used engine.
Check before the first start:
- Injection pump — Check for smoke and starting problems.
- Head cracks — Pressure-test the system.
- Timing belt (M21) — Ask for the belt history.
Extra steps for this engine: Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry.
M51
Oil: 5W-40 or 10W-40 diesel-rated oil. Timing: Timing chain.
Check the injection pump and the head.
Check before the first start:
- Injection pump — Check for smoke and starting problems.
- Head cracks — Pressure-test the system.
- Turbocharger — Look for smoke.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry.
M47
Oil: 5W-30 BMW Longlife-04, about 5.25 litres. Timing: Timing chain at the front.
Fit swirl flap blanks and clean the intake when installing a used M47.
Check before the first start:
- Swirl flaps — Check whether the flaps have been removed or replaced with blanks.
- EGR valve and cooler — Check for EGR fault codes and coolant loss.
- Injectors — Read injector correction values.
- Turbocharger — Check shaft play.
- Glow plugs — Check the glow plug system.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry.
M57
Oil: 5W-30 BMW Longlife-04, about 6.5 to 7.5 litres. Timing: Timing chain at the front.
Fit swirl flap blanks when installing a used M57. Conversions need the right sump and wiring.
Check before the first start:
- Swirl flaps — Check whether the flaps have been removed or replaced with blanks.
- EGR valve and cooler — Check for EGR fault codes and coolant loss.
- Injectors — Read injector correction values.
- Turbocharger — Check shaft play and actuator movement.
- Thermostat and viscous fan — Check the coolant temperature.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry.
M67
Oil: 5W-30 BMW Longlife-04. Timing: Timing chains.
Ask for service history.
Check before the first start:
- Turbochargers — Check shaft play and smoke.
- Injectors — Read injector correction values.
- Glow plugs and wiring — Check the glow system.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry.
N47
Oil: 5W-30 BMW Longlife-04, about 5.25 litres. Timing: Timing chain at the rear (gearbox end).
Replace the timing chain and guides when fitting a used N47 unless they were recently done.
Check before the first start:
- Timing chain — Listen for a rattle at the gearbox end on a cold start and ask whether the chain has been replaced.
- Swirl flaps — Check the intake for damage.
- EGR cooler — Check the recall status and for coolant loss.
- Diesel particulate filter — Read the soot load and DPF fault codes.
- Injectors — Read injector correction values.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry. Check the particulate filter: If the old engine failed with oil or coolant entering the exhaust, the DPF may be contaminated. Check its back-pressure before relying on it.
N57
Oil: 5W-30 BMW Longlife-04, about 6.5 litres. Timing: Timing chain at the rear (gearbox end).
Check the EGR recall and the swirl flaps when buying.
Check before the first start:
- Swirl flaps — Check the intake.
- EGR cooler — Check the recall status.
- Diesel particulate filter — Read the soot load.
- Timing chain — Listen for a rattle on a cold start.
- Injectors — Read injector correction values.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry. Check the particulate filter: If the old engine failed with oil or coolant entering the exhaust, the DPF may be contaminated. Check its back-pressure before relying on it.
B37
Oil: 0W-30 or 5W-30 BMW Longlife-04. Timing: Timing chain at the rear (gearbox end).
Check front-drive (B37C) or rear-drive (B37D) before ordering.
Check before the first start:
- EGR system — Check for EGR fault codes.
- Diesel particulate filter — Read the soot load.
- Engine mounts — Check the mounts.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry. Check the particulate filter: If the old engine failed with oil or coolant entering the exhaust, the DPF may be contaminated. Check its back-pressure before relying on it.
B47
Oil: 0W-30 or 5W-30 BMW Longlife-04, about 5.25 litres. Timing: Timing chain at the rear (gearbox end).
Check front-drive (B47C) or rear-drive (B47D) before ordering.
Check before the first start:
- EGR cooler — Check the recall status for the donor car.
- Diesel particulate filter — Read the soot load.
- Injectors — Read injector correction values.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry. Check the particulate filter: If the old engine failed with oil or coolant entering the exhaust, the DPF may be contaminated. Check its back-pressure before relying on it.
B57
Oil: 0W-30 or 5W-30 BMW Longlife-04, about 6.5 litres. Timing: Timing chain at the rear (gearbox end).
Check the version (B57D30A, B, C or S) before ordering.
Check before the first start:
- EGR cooler — Check the recall status.
- Diesel particulate filter — Read the soot load.
- Turbo actuators — Check for boost faults.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later. Replace the rear timing chain if in doubt: On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting. Prepare the turbo: Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting. Code the injectors and bleed the fuel: Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry. Check the particulate filter: If the old engine failed with oil or coolant entering the exhaust, the DPF may be contaminated. Check its back-pressure before relying on it.
MINI Prince
Oil: 5W-30 BMW Longlife-01, about 4.2 litres. Timing: Timing chain at the front.
Replace the chain and tensioner when fitting a used N12 or N14.
Check before the first start:
- Timing chain — Listen for a rattle on a cold start.
- Carbon build-up — Borescope inspection.
- Oil consumption — Ask for consumption figures.
- Water pump and thermostat housing — Check for coolant loss.
Extra steps for this engine: Inspect or replace the timing chain parts: Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
M31, M337 and S70
Oil: Period-correct oil chosen with a specialist. Timing: Varies by engine.
Keep documentation with the engine.
Check before the first start:
- Age and storage — Ask for photographs of the internals and the history.
- Originality — Check the engine number against the car's documents.
If something is wrong after the first start
If your current engine is showing one of these symptoms, this table helps you judge whether it can be repaired or whether a replacement engine is the better route.
| Symptom | Likely cause |
|---|---|
| Knocking from the bottom of the engine | A deep knock that rises with engine speed usually means worn rod or main bearings. |
| Overheating or losing coolant | Coolant loss without visible leaks points to a head gasket or a cracked head; visible leaks point to the water pump, hoses, thermostat housing or expansion tank. |
| White smoke that smells sweet | Coolant burning in the cylinders, from a head gasket, a cracked head or, on diesels, a leaking EGR cooler. |
| Blue smoke | Oil burning in the cylinders. |
| Rough idle or misfire | Ignition coils, spark plugs, injectors and vacuum leaks are the usual causes. |
| Loss of power | Start with the simple things: air filter, boost leaks on turbo engines, fuel pressure and fault codes. |
| Rattle for a few seconds after a cold start | The classic sign of a weak timing chain tensioner or stretched chain. |
| Rattle or whine from the gearbox end | On engines with the timing chain at the rear, a rattle or whine from the back of the engine is the warning sign of chain stretch or guide wear. |
| Whistle, loss of boost or limp mode | A split charge pipe, a sticking wastegate or worn turbo bearings. |
| Black smoke under acceleration | Too much fuel for the air available: boost leaks, a sticking EGR valve, a dirty air mass meter or a leaking injector. |
| Hard starting when cold | Glow plugs or the glow plug control unit. |
| Particulate filter warning | Short trips stop the DPF from regenerating. |
| Poor low-down torque and uneven idle | VANOS seals or solenoids. |
| Limp mode with a Valvetronic fault | The Valvetronic motor, its eccentric shaft sensor or the wiring. |
| Long cranking before the engine starts | On direct-injection engines, a weak high-pressure fuel pump or leaking injector lets pressure drop when the engine is off. |
| Engine stops suddenly and will not restart | On belt-driven engines, a snapped timing belt. |
| Oil pressure warning or bearing noise at high revs | On M engines, a warning at high revs can be the first sign of bearing wear. |
Knocking from the bottom of the engine. A deep knock that rises with engine speed usually means worn rod or main bearings. Stop driving: bearing failure ends with a broken connecting rod. A used engine is normally the most economical fix once the bottom end is damaged.
Overheating or losing coolant. Coolant loss without visible leaks points to a head gasket or a cracked head; visible leaks point to the water pump, hoses, thermostat housing or expansion tank. Overheating should be fixed before it warps the head.
White smoke that smells sweet. Coolant burning in the cylinders, from a head gasket, a cracked head or, on diesels, a leaking EGR cooler. Check the coolant level and look for oil in the coolant.
Blue smoke. Oil burning in the cylinders. A puff on start-up points to valve stem seals; constant smoke under load points to piston rings or, on turbo engines, turbo seals.
Rough idle or misfire. Ignition coils, spark plugs, injectors and vacuum leaks are the usual causes. A misfire on one cylinder that moves when you swap coils is a coil; one that stays is a plug, injector or compression problem.
Loss of power. Start with the simple things: air filter, boost leaks on turbo engines, fuel pressure and fault codes. A gradual loss with poor compression on a test points to internal wear.
Rattle for a few seconds after a cold start. The classic sign of a weak timing chain tensioner or stretched chain. It must be checked quickly: a chain that jumps a tooth can bend valves.
Rattle or whine from the gearbox end. On engines with the timing chain at the rear, a rattle or whine from the back of the engine is the warning sign of chain stretch or guide wear.
Whistle, loss of boost or limp mode. A split charge pipe, a sticking wastegate or worn turbo bearings. Check the pipes first, then the turbo shaft for play.
Black smoke under acceleration. Too much fuel for the air available: boost leaks, a sticking EGR valve, a dirty air mass meter or a leaking injector.
Hard starting when cold. Glow plugs or the glow plug control unit. On older diesels, also check the injection pump and fuel lines for air leaks.
Particulate filter warning. Short trips stop the DPF from regenerating. A long motorway run often clears it; a filter that keeps blocking may be covering an injector, EGR or turbo problem.
Poor low-down torque and uneven idle. VANOS seals or solenoids. The engine may run well at high revs but feel flat and lumpy at low speed.
Limp mode with a Valvetronic fault. The Valvetronic motor, its eccentric shaft sensor or the wiring. The engine runs on a reduced throttle until it is repaired.
Long cranking before the engine starts. On direct-injection engines, a weak high-pressure fuel pump or leaking injector lets pressure drop when the engine is off.
Engine stops suddenly and will not restart. On belt-driven engines, a snapped timing belt. Do not keep cranking: on an interference engine the valves are probably already bent.
Oil pressure warning or bearing noise at high revs. On M engines, a warning at high revs can be the first sign of bearing wear. Check the oil level and stop driving hard until it is diagnosed.
Fitting questions
Should a workshop fit my engine?
Yes. The warranty asks that the engine is fitted by a qualified mechanic or workshop.
An engine swap involves lifting gear, wiring, coding and fluids. A workshop has the tools and the know-how to do it right.
Ask your workshop to keep a record of the fluids and parts they use.
If your workshop has questions about the unit, they can call the desk directly.
What should I do before the first start?
Fit a new oil filter, fill with the correct oil and refill the coolant. On turbo engines, fill the turbo oil feed with clean oil.
Turn the engine over without fuel or ignition until the oil pressure light goes out. This brings oil to every bearing before the engine runs.
Check all hoses, clips and electrical plugs, then start the engine and let it idle while you look for leaks.
Bleed the cooling system and top up as the air comes out.
How should I drive in the first 1,000 km?
Drive gently and vary the speed. Avoid full throttle and very high revs for the first few hundred kilometres.
Watch the temperature and the oil pressure, and check the oil and coolant level often.
Many fitters change the oil and the filter again after the first 1,000 km. It is cheap and removes any dirt from the fitting.
Report any warning light or strange noise to us right away.
Do I need to code the engine computer after a swap?
If you reuse the engine computer from your car, and the new engine has the same code, little or no coding is usually needed.
If the engine is a different version, or the engine computer comes with the engine, a specialist may need to code it to your car's immobiliser and options.
Ask us before you order. We tell you if the unit needs coding for your car.
Your VIN helps us give the right answer.
Can I reuse parts from my old engine?
Often yes. Turbos, injectors, the alternator and other ancillaries can move over if they are in good condition.
Parts that failed with the old engine, or that look worn, should be replaced. A worn turbo can damage a good engine.
Always use new gaskets and seals where parts are moved over.
Our listings show what is fitted to each unit, so you can plan what to reuse.
Delivery, warranty and payment
Every engine we sell is drained, sealed at each opening, strapped to a heat-treated pallet and shrink-wrapped before it leaves Hamburg. You receive photographs of the packed engine and a tracking number.
Door-to-door delivery is included to the address you give at checkout. Typical delivery takes three to five working days within Germany and neighbouring countries and five to ten working days to the rest of Europe and the UK.
A 12-month warranty covers eligible internal failure when the engine is fitted by a qualified workshop with new fluids and filters. You can pay by card, bank transfer or crypto and receive the invoice by email straight away.
We deliver BMW engines from Hamburg to customers across Europe and beyond. Typical door-to-door times and customs status:
| Country | Typical delivery | Customs and VAT |
|---|---|---|
| Germany | 2–4 working days | No customs; German VAT on the invoice |
| Netherlands | 3–5 working days | EU delivery, no customs |
| Belgium | 3–5 working days | EU delivery, no customs |
| Austria | 3–5 working days | EU delivery, no customs |
| Denmark | 3–5 working days | EU delivery, no customs |
| Poland | 3–6 working days | EU delivery, no customs |
| Czech Republic | 3–6 working days | EU delivery, no customs |
| France | 4–7 working days | EU delivery, no customs |
| Italy | 5–8 working days | EU delivery, no customs |
| Spain | 5–8 working days | EU delivery, no customs |
| Portugal | 6–9 working days | EU delivery, no customs |
| Sweden | 5–8 working days | EU delivery, no customs |
| Norway | 6–10 working days | Export; import VAT and duty in Norway |
| Switzerland | 5–8 working days | Export; import VAT and duty in Switzerland |
| United Kingdom | 5–10 working days | Export; UK import VAT and duty on arrival |
| Ireland | 6–10 working days | EU delivery, no customs |
| United States | Quoted per order | Export; US import duties apply |
| United Arab Emirates | Quoted per order | Export; UAE import duties apply |
Times are typical for pallet delivery after dispatch and can vary with holidays and remote addresses. Business buyers in the EU with a valid VAT number can order without German VAT.
Glossary
- VANOS — BMW's variable camshaft timing system. It adjusts the intake camshaft (single VANOS) or both camshafts (double VANOS) to improve torque and emissions.
- Valvetronic — BMW's variable valve lift system. It controls engine load with the intake valves instead of a throttle plate, improving economy.
- Direct injection — Fuel is injected directly into the cylinder instead of the intake port. It improves efficiency but can cause carbon build-up on the intake valves.
- Wastegate — A valve that lets exhaust gas bypass the turbine to control boost pressure. Worn wastegates rattle and can cause boost faults.
- DPF — Diesel particulate filter. It traps soot and burns it off during regeneration, which needs longer journeys.
- EGR — Exhaust gas recirculation. It feeds some exhaust back into the intake to reduce NOx emissions but builds up soot.
- Swirl flaps — Flaps in the intake manifold that create swirl at low revs. On some BMW diesels they can break and enter the engine.
- Common rail — A diesel injection system with a high-pressure fuel rail feeding all injectors. It allows precise, multiple injections per cycle.
- Long block — An engine with the block, head and internals but without most ancillaries such as manifolds, turbo, alternator or starter.
- Dressed engine — An engine with most ancillaries fitted, ready to install with fewer parts transferred.
- Compression test — A measurement of the pressure each cylinder builds when cranked. Even readings show healthy rings and valves.
- Leak-down test — A test that pressurises each cylinder and measures how much air escapes, showing where any leak is.
- LCI — Life Cycle Impulse, BMW's name for a mid-life update. Engines often change at the LCI.
- xDrive — BMW's all-wheel-drive system. xDrive cars often use a different sump and oil pickup.
- DME — Digital Motor Electronics, BMW's name for the engine control unit.
- CAS, FEM and BDC — The immobiliser and body modules that must be matched to the engine control unit on modern BMWs.
- Rod bearings — The bearings between the connecting rods and the crankshaft. On several M engines they wear and are replaced preventively.
- ITB — Individual throttle bodies, one per cylinder, used on most naturally aspirated M engines for sharp response.
- Timing chain tensioner — A hydraulic or spring device that keeps the timing chain tight. Worn tensioners cause cold-start rattle.
- Rear-mounted timing chain — A timing chain at the gearbox end of the engine. Replacing it normally requires removing the engine.
- Timing belt — A rubber belt that drives the camshaft. It must be replaced on time to avoid valve damage.
- TU — Technical Update, BMW's suffix for a revised version of an engine.
Browse every engine in stock or ask the Hamburg desk — send your VIN and we will confirm the right engine the same day.
