BMW 116i (E81 and E87) engine: which one, problems and replacement

The BMW 116i in the first 1 Series three-door generation (E81 and E87, built 2007–2012) was built with 2 different engines over its life: the N45B16 (116 hp, 2004–2011) and the N43B16 (122 hp, 2007–2011).

This guide tells you which engine your 116i has, what goes wrong with it, what a replacement costs from our stock and what else to plan for when you fit one.

• Generation: first 1 Series three-door, 2007–2012
• Body styles: E81 (hatchback) and E87 (hatchback)
• Engines: N45B16, N43B16
• Output: 116 hp and 122 hp
• Replacement engines in stock: ask the desk for the next arrival

Which engine is in your 116i?

N45B16 in the 116i

The N45B16 was used in the E87 116i, built 2004–2011. It is a 1.6 L naturally aspirated petrol inline-4 with 116 hp and 150 Nm. Compared with the N43B16 (122 hp), it is the mildest.

Reading the code: N marks an N-series code, the generation of BMW engines introduced from 2001; 45 is the family number; B stands for petrol (from the German Benzin); 16 is the capacity in decilitres, so 1.6 litres.

N43B16 in the 116i

The N43B16 was used in the E81 116i and E87 116i, built 2007–2011. It is a 1.6 L naturally aspirated petrol inline-4 with 122 hp and 160 Nm. Compared with the N45B16 (116 hp), it is the strongest.

Reading the code: N marks an N-series code, the generation of BMW engines introduced from 2001; 43 is the family number; B stands for petrol (from the German Benzin); 16 is the capacity in decilitres, so 1.6 litres.

116i engines by model year

The 116i kept the same engine for the whole E81 and E87 run, which makes ordering simple: any unit with the same code fits, subject to the gearbox, drive type and sump.

Other cars with the same engine as the 116i

A replacement engine does not have to come from another 116i. These models left the factory with the same engine code, so a unit from any of them is a candidate donor once the sump, mounts and ancillaries are matched to your car.

N45B16: BMW E90 316i.

How to confirm your engine code

Because the 116i used more than one engine, the badge alone does not tell you which one your car has. The build date is the first clue; the VIN is the proof. Send us the last seven characters of the VIN and we read the engine code from BMW's records, or look for the code stamped on the block. How to find your BMW engine code.

Known 116i engine problems

N45B16 (N42 and N46 family)

The N45B16 in the 116i shares the known weak points of the N42 and N46 family. Full N42 and N46 guide.

Oil consumption. Valve stem seals and piston rings let oil through; consumption above one litre per 1,000 km is not unusual on neglected engines.

Timing chain stretch. The N46 chain and tensioner wear, causing rattle and timing faults.

Valvetronic motor and eccentric shaft sensor. Both can fail and leave the engine in limp mode.

Vacuum pump and oil leaks. The vacuum pump seal and the valve cover gasket leak oil.

Crankcase ventilation. The CCV diaphragm splits, causing lean codes and a whistle.

N43B16 (N43 family)

The N43B16 in the 116i shares the known weak points of the N43 family. Full N43 guide.

Piezo injectors. Injectors leak or misfire, especially with poor fuel.

Ignition coils and spark plugs. Lean-burn combustion is hard on coils and plugs; misfires are common.

NOx sensor and catalyst. The NOx storage catalyst and sensor degrade, especially with high-sulphur fuel.

Timing chain. Chain stretch occurs at higher mileage.

Vacuum pump and oil leaks. Like the N46, the vacuum pump and valve cover leak.

Symptoms to watch for on the 116i

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.

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.

Looking after the 116i engine

N42 and N46 engines

• Oil: 5W-30 BMW Longlife-01 or Longlife-04, about 4.25 litres.
• Service interval: Oil every 15,000 km; shorten to 10,000 km to protect the chain.
• Timing drive: Timing chain at the front with balance shafts.
• Workshop notes: Replace the timing chain, tensioner and valve stem seals when fitting a high-mileage used N46.

N43 engines

• Oil: 5W-30 BMW Longlife-01 or Longlife-04, about 4.25 litres.
• Service interval: Oil every 15,000 km; spark plugs every 60,000 km.
• Timing drive: Timing chain at the front.
• Workshop notes: Use good-quality, low-sulphur petrol. Fit new coils and plugs to a used N43 before first start.

Buying a used engine for the 116i: checklist

1. Compression or leak-down figures. Even compression across all cylinders tells you more than mileage. Ask for the figures, not just a pass or fail, and compare the highest and lowest readings: a spread above 10 to 15 percent deserves a question.
2. Ask how the donor car was damaged. Most good used engines come from cars with body damage. A front-end impact can crack sensors, the timing cover or the sump; a rear or side impact usually leaves the engine untouched. The yard records the damage on each unit.
3. Gearbox and flywheel match. Manual and automatic engines differ at the flywheel or flexplate, and sometimes at the crankshaft spigot. Make sure the engine you buy matches your gearbox or that you transfer the right parts.
4. Photographs from every side. Good suppliers photograph the actual engine you will receive. Look for the block stamp, the sump, the timing cover and any broken brackets or connectors in the pictures.
5. Sump, oil pickup and drive variants. Rear-drive, xDrive and front-drive cars can use different sumps, oil pickups and engine mounts even with the same engine code. Check that the sump matches your subframe and front axle.
6. Timing chain noise. Listen for a rattle at the front of the engine for the first seconds after a cold start. On an engine that cannot be run, look at the chain guides through the oil filler or with the valve cover off.
7. VANOS operation. Rough idle, a rattle from the front of the head and a loss of torque at low revs point to VANOS seals or solenoids. These are serviceable parts and are easier to renew with the engine out.
8. Double VANOS units and solenoids. Ask for the adaptation values or fault history if the engine was running. Solenoids are inexpensive and are often replaced as a matter of course on a used engine.
9. Valvetronic motor and eccentric shaft sensor. The Valvetronic motor and its sensor cause limp-mode faults when they fail. Inspect the connector and the seal around the motor for oil.
10. Injectors and high-pressure fuel pump. Direct-injection engines rely on high-pressure pumps and precise injectors. Ask whether the injectors are original or updated and whether there were fuel pressure faults.

BMW 116i replacement engine cost

We do not have a 116i engine on the shelf at the moment. Send us your VIN or the code you need and the desk will tell you when the next unit arrives and what it will cost.

On top of the engine, budget for the workshop's labour and the parts that are best replaced while the engine is out: engine mounts, the rear main seal, cooling parts, a clutch or converter seal, fluids and filters.

Will it fit my 116i?

Will the N45B16 fit my BMW E87 116i?

For the BMW E87 116i, the N45B16 is the factory engine and the one to order. The first 1 Series five-door was built 2004–2011, and the N45B16 was produced 2004–2011, so check that your car's build date falls inside that window. Confirm the drive type (rear-drive or xDrive), the gearbox (manual or automatic) and the emissions standard, because these can change the sump, the flywheel and the software. Send us the VIN and we check all of it for you.

How much is a replacement engine for a BMW E87 116i?

We do not have an N45B16 on the shelf for the E87 116i at the moment. Units arrive regularly; send us your VIN and we will tell you when the next one is ready and what it will cost, including delivery.

Will the N43B16 fit my BMW E81 116i?

The N43B16 is the original engine for the BMW E81 116i, which makes it the straightforward choice. The first 1 Series three-door was built 2007–2012, and the N43B16 was produced 2007–2011, so check that your car's build date falls inside that window. Confirm the drive type (rear-drive or xDrive), the gearbox (manual or automatic) and the emissions standard, because these can change the sump, the flywheel and the software. Send us the VIN and we check all of it for you.

How much is a replacement engine for a BMW E81 116i?

We do not have an N43B16 on the shelf for the E81 116i at the moment. Units arrive regularly; send us your VIN and we will tell you when the next one is ready and what it will cost, including delivery.

Will the N43B16 fit my BMW E87 116i?

For the BMW E87 116i, the N43B16 is the factory engine and the one to order. The first 1 Series five-door was built 2004–2011, and the N43B16 was produced 2007–2011, so check that your car's build date falls inside that window. Confirm the drive type (rear-drive or xDrive), the gearbox (manual or automatic) and the emissions standard, because these can change the sump, the flywheel and the software. Send us the VIN and we check all of it for you.

How much is a replacement engine for a BMW E87 116i?

We do not have an N43B16 on the shelf for the E87 116i at the moment. Units arrive regularly; send us your VIN and we will tell you when the next one is ready and what it will cost, including delivery.

Engine swaps and upgrades for the 116i

These engines were fitted to other versions of the E81 and E87 at the factory, which makes them the most practical upgrades: the body was designed around them and many parts are shared.

Can I fit the N46B20 in my 116i?

Yes, it is one of the more common upgrades. Both are petrol inline-4 engines, so the mounting points are similar, but the N46B20 needs its own wiring and engine control unit, the matching gearbox or clutch, and often a different sump, cooling and exhaust. The gain is 28 hp and 40 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Can I fit the M47TUD20 in my 116i?

It is a full conversion: the M47TUD20 runs on diesel and the N43B16 on petrol, so the fuel system, wiring, engine control unit, instrument coding and usually the gearbox change too. The gain is 28 hp and 170 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Can I fit the N43B20 in my 116i?

Yes, it is one of the more common upgrades. Both are petrol inline-4 engines, so the mounting points are similar, but the N43B20 needs its own wiring and engine control unit, the matching gearbox or clutch, and often a different sump, cooling and exhaust. The gain is 48 hp and 50 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Fitting a replacement engine in the 116i

1. 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.
2. Reset VANOS adaptations. Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
3. Teach the Valvetronic limit stops. Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
4. 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.
5. 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.
6. 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.
7. 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.

The full fitting and first-start procedure.

Delivery, warranty and payment

Before a 116i engine leaves our Hamburg yard it is drained of oil and coolant, every opening is sealed, and it is strapped to a pallet and wrapped. We send photographs of the packed unit and the tracking details.

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.

All E81 and E87 engines · N42 and N46 engine guide · N43 engine guide · BMW 116i engines for sale · Send us your VIN