Classic BMW 02, E3, E9 and E21 engines: every engine, fitment and price

The 02 Series, the E3 and E9 sixes and the first 3 Series (E21) used the M10, M20 and M30 engines, and the 2002 Turbo used the M31.

In total, 5 model and engine combinations are listed for the Classic BMW 02, E3, E9 and E21 in our data, using 3 engine families: M31, M337 and S70, M10 and M20. Production covered 1968–1977, 1968–1975, 1966–1977 and 1975–1983. We currently hold 0 engines that suit these cars.

Every Classic BMW 02, E3, E9 and E21 engine at a glance

Classic BMW 02, E3, E9 and E21: petrol engines

M31, M337 and S70 in the Classic BMW 02, E3, E9 and E21

For the E20 2002 Turbo, BMW fitted the M31 — 2.0 L, turbocharged, 170 hp.

The M31 combined the M10 with a KKK turbocharger and Kugelfischer mechanical injection to make 170 hp.

On the M31, M337 and S70, our workshop watches for age and storage and originality. Keep documentation with the engine.

Read our full M31, M337 and S70 guide

M10 in the Classic BMW 02, E3, E9 and E21

For the E21 316, BMW fitted the M10B16 — 1.6 L, naturally aspirated, 90 hp.

E21 318: M10B18, 1.8 L, 105 hp and 145 Nm (1962–1988).

For the E21 320, BMW fitted the M10B20 — 2.0 L, naturally aspirated, 125 hp.

BMW designed the M10 under Alex von Falkenhausen with a canted block, a chain-driven camshaft and a crossflow aluminium head.

On the M10, our workshop watches for camshaft and rocker wear, timing chain guides and tensioner and warped head after overheating. 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.

Read our full M10 guide

M20 in the Classic BMW 02, E3, E9 and E21

The E21 323i uses the M20B23, a 2.3 L inline-6 rated at 139 hp and 205 Nm, built 1977–1987.

The M20 arrived in the E12 520/6 and E21 320/6 as a 2.0 litre with a single belt-driven camshaft.

On the M20, our workshop watches for timing belt failure, cylinder head cracks and rocker arm and shaft wear. Valve clearance is set cold at about 0.25 mm with eccentric adjusters. Use a new head bolt set whenever the head comes off.

Read our full M20 guide

Will it fit? Classic BMW 02, E3, E9 and E21 engine questions

Will the M31 fit my BMW E20 2002 Turbo?

For the BMW E20 2002 Turbo, the M31 is the factory engine and the one to order. The 02 Series was built 1966–1977, and the M31 was produced 1973–1975, 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 E20 2002 Turbo?

We do not have an M31 on the shelf for the E20 2002 Turbo 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 M10B16 fit my BMW E21 316?

For the BMW E21 316, the M10B16 is the factory engine and the one to order. The first 3 Series was built 1975–1983, and the M10B16 was produced 1962–1988, 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 E21 316?

We do not have an M10B16 on the shelf for the E21 316 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 M10B18 fit my BMW E21 318?

The M10B18 is the original engine for the BMW E21 318, which makes it the straightforward choice. The first 3 Series was built 1975–1983, and the M10B18 was produced 1962–1988, 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 E21 318?

We do not have an M10B18 on the shelf for the E21 318 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 M10B20 fit my BMW E21 320?

Yes, the BMW E21 320 left the factory with the M10B20, so an M10B20 from another car is the direct replacement. The first 3 Series was built 1975–1983, and the M10B20 was produced 1962–1988, 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 E21 320?

We do not have an M10B20 on the shelf for the E21 320 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 M20B23 fit my BMW E21 323i?

For the BMW E21 323i, the M20B23 is the factory engine and the one to order. The first 3 Series was built 1975–1983, and the M20B23 was produced 1977–1987, 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 E21 323i?

We do not have an M20B23 on the shelf for the E21 323i 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 swap questions for the Classic BMW 02, E3, E9 and E21

Owners often ask whether a more powerful engine from another Classic BMW 02, E3, E9 and E21 model can be fitted. These answers show what each upgrade involves.

Can I fit the M31 from the E20 2002 Turbo into an E21 316?

It is possible, and it is one of the more common upgrades. Both engines are petrol inline-4 units, so the engine bay and mounting points are similar, but the M31 needs its own wiring harness and ECU, the matching gearbox or clutch, and often a different sump, cooling and exhaust. The gain is 80 hp and 110 Nm. In Germany and most of Europe a swap must be inspected and registered; check with your testing station first.

Can I fit the M20B23 from the E21 323i into an E21 316?

It is a conversion rather than a replacement. The M20B23 is an inline-6 and the M10B16 an inline-4, so mounts, sump, cooling, exhaust, wiring and ECU all change. The gain is 49 hp and 75 Nm. In Germany and most of Europe a swap must be inspected and registered; check with your testing station first.

Can I fit the M31 from the E20 2002 Turbo into an E21 318?

It is possible, and it is one of the more common upgrades. Both engines are petrol inline-4 units, so the engine bay and mounting points are similar, but the M31 needs its own wiring harness and ECU, the matching gearbox or clutch, and often a different sump, cooling and exhaust. The gain is 65 hp and 95 Nm. In Germany and most of Europe a swap must be inspected and registered; check with your testing station first.

Can I fit the M20B23 from the E21 323i into an E21 318?

It is a conversion rather than a replacement. The M20B23 is an inline-6 and the M10B18 an inline-4, so mounts, sump, cooling, exhaust, wiring and ECU all change. The gain is 34 hp and 60 Nm. In Germany and most of Europe a swap must be inspected and registered; check with your testing station first.

Can I fit the M31 from the E20 2002 Turbo into an E21 320?

It is possible, and it is one of the more common upgrades. Both engines are petrol inline-4 units, so the engine bay and mounting points are similar, but the M31 needs its own wiring harness and ECU, the matching gearbox or clutch, and often a different sump, cooling and exhaust. The gain is 45 hp and 70 Nm. In Germany and most of Europe a swap must be inspected and registered; check with your testing station first.

Can I fit the M20B23 from the E21 323i into an E21 320?

It is a conversion rather than a replacement. The M20B23 is an inline-6 and the M10B20 an inline-4, so mounts, sump, cooling, exhaust, wiring and ECU all change. The gain is 14 hp and 35 Nm. In Germany and most of Europe a swap must be inspected and registered; check with your testing station first.

Can I fit the M31 from the E20 2002 Turbo into an E21 323i?

It is a conversion rather than a replacement. The M31 is an inline-4 and the M20B23 an inline-6, so mounts, sump, cooling, exhaust, wiring and ECU all change. The gain is 31 hp and 35 Nm. In Germany and most of Europe a swap must be inspected and registered; check with your testing station first.

Fitment and swap notes for the Classic BMW 02, E3, E9 and E21

• Matching numbers matter on collectible cars.

Engines from the same family usually share mounts and gearbox bolt patterns, but wiring, ECU, sump and cooling differ between versions. Moving to a different family is a conversion, not a replacement.

M31, M337 and S70: Collectors keep them standard.

M10: The M10 responds to a sharper camshaft, a 2.0 litre conversion on 1.8 cars and twin Weber or Dellorto carburettors. Historic racers often fit a 2002 tii head and injection. Keep the original block if the car's identity matters.

M20: The classic upgrade is the M20 'stroker': a 2.7 eta block and crank with a 885 head from a 325i, giving more torque without losing the rev range. Chip tuning on Motronic cars and a free-flowing exhaust add modest gains.

Known problems by engine in the Classic BMW 02, E3, E9 and E21

M31, M337 and S70

• Age and storage. Ask for photographs of the internals and the history.
• Originality. Check the engine number against the car's documents.

M10

• 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.

M20

• 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.

How to identify the right engine for your Classic BMW 02, E3, E9 and E21

Start with the VIN. The last seven characters identify your car in BMW's systems, and from them we can confirm the engine code, the production date, the gearbox and whether the car has xDrive. That is the only reliable way to order.

Next, check the stamp on the block. On most BMW four- and six-cylinder engines it sits on the left side of the block below the intake; on V engines it is usually at the back near the gearbox. The stamp shows the engine code and serial number.

Finally, compare the ancillaries. Two engines with the same code can carry different turbos, injectors, manifolds or sensors depending on the model and market. Our listings show what is fitted to each unit.

Classic BMW 02, E3, E9 and E21 engine prices

We do not have a Classic BMW 02, E3, E9 and E21 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.

Classic BMW 02, E3, E9 and E21 engines in stock now

Buying checklist for a Classic BMW 02, E3, E9 and E21 engine

1. Confirm the exact engine code. Read the code stamped on the block and compare it with the code for your car. Send us the last seven characters of the VIN and we confirm the match before anything is paid.
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. 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.
4. Look at the oil and coolant. Clean oil without metal particles and coolant without oil are good signs. Milky oil, oily coolant or a burnt smell mean the engine needs further checks before it is fitted.
5. 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.
6. List of what is fitted. Engines are sold with different ancillaries: some have the turbo, injectors, manifolds, alternator and starter, others are long blocks. Agree the list in writing so you know which parts must come from your old engine.
7. 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.
8. 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.
9. Warranty terms in writing. Read what the warranty covers, how long it runs and what fitting conditions apply. Most warranties require a qualified workshop, new fluids and filters, and replacement of the cooling parts that caused the original failure.
10. Why your old engine failed. Before fitting a replacement, find out why the original failed. An overheating radiator, a blocked intercooler or a failed turbo can destroy a second engine if they are not fixed.
11. 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.
12. Timing belt history. A timing belt must be changed on time and distance. With no dated record, treat the belt, tensioner and water pump as due and replace them before the first start.
13. Originality and numbers. For collectible cars, the engine number and correct ancillaries add value. Photograph the stamp and keep it with the car's documents.

Fitting an engine to your Classic BMW 02, E3, E9 and E21

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. 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.
12. 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.

Diagnosing engine trouble in a Classic BMW 02, E3, E9 and E21

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.

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.

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.

Repair or replace the engine in your Classic BMW 02, E3, E9 and E21?

As a rule, bolt-on faults are worth repairing and internal damage is not. Seals, sensors, coils, injectors, pumps and turbos can be replaced in the car. Once the bearings, crankshaft, bores or head of an engine are damaged, a used engine is usually cheaper and quicker than a rebuild.

Ask your workshop for a written diagnosis before deciding. A compression test, an oil analysis and a borescope inspection take an hour or two and remove most of the guesswork.

Delivery, warranty and payment

Every Classic BMW 02, E3, E9 and E21 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.

Every engine carries a 12-month warranty on eligible internal failure when a qualified workshop fits it with new fluids and filters. Payment is by card, bank transfer or crypto; your invoice is emailed as soon as you order.

We deliver Classic BMW 02, E3, E9 and E21 engines from Hamburg to customers across Europe and beyond. Typical door-to-door times and customs status:

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.

Questions about Classic BMW 02, E3, E9 and E21 engines

Will the M10B18 engine fit my BMW E21 316?

Yes, if your BMW E21 316 was built with the M10B18. BMW used this 1.8 liter (1,766 cc) petrol engine with 77 kW (105 HP) in the E21 316 from about 1975 to 1988.

In our records the M10B18 is the engine for the E21 316, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E21 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines · Search M10B18 in the shop

How much is a replacement M10B18 engine for a BMW E21 316?

A used M10B18 for the BMW E21 316 costs from about 800 € to 1.450 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M10B18 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines · Search M10B18 in the shop

Will the M10B18 engine fit my BMW E21 318i?

Yes, if your BMW E21 318i was built with the M10B18. BMW used this 1.8 liter (1,766 cc) petrol engine with 77 kW (105 HP) in the E21 318i from about 1975 to 1988.

In our records the M10B18 is the engine for the E21 318i, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E21 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines · Search M10B18 in the shop

How much is a replacement M10B18 engine for a BMW E21 318i?

A used M10B18 for the BMW E21 318i costs from about 800 € to 1.450 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M10B18 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines · Search M10B18 in the shop

Will the M20B20 engine fit my BMW E21 320i?

Yes, if your BMW E21 320i was built with the M20B20. BMW used this 2.0 liter (1,991 cc) petrol engine with 95 kW (129 HP) in the E21 320i from about 1977 to 1992.

In our records the M20B20 is the engine for the E21 320i, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E21 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

How much is a replacement M20B20 engine for a BMW E21 320i?

A used M20B20 for the BMW E21 320i costs from about 1.000 € to 1.700 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M20B20 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

Questions about the engines in the Classic BMW 02, E3, E9 and E21

Is the BMW M20B20 a diesel or petrol engine?

The M20B20 is a petrol engine. It is a 2.0 liter (1,991 cc) inline 6, SOHC, 12 valve unit with no turbo (naturally aspirated), and it was built to the Euro 1 emission standard.

The emission standard matters for registration and for low-emission zones in many cities. When you replace an engine with the same code, the car keeps the same paperwork and the same emission class.

Petrol versions need the correct catalytic converters and oxygen sensors on the car to stay legal and to keep the engine computer happy. Reuse the parts from your car if they are in good condition.

If you are not sure which version you need, send us your VIN. We tell you the right code for free.

See all M20 Engines · Search M20B20 in the shop

What is the BMW M20B20 engine?

The BMW M20B20 is a 2.0 liter (1,991 cc) petrol engine from the M20 family. It has an inline 6, SOHC, 12 valve layout with no turbo (naturally aspirated), and makes 95 kW (129 HP) with 174 Nm of torque. BMW built it from 1977 to 1992 and it meets the Euro 1 emission standard.

You find the M20B20 in the BMW E30 320i, BMW E28 520i and BMW E21 320i. What we list: BMW M20 small-six petrol engines for E30 and E28.

At Autowerke Engines every M20B20 is a real used engine from our yard in Hamburg. The photos on each listing show the actual engine, not a stock picture. The yard checks the code, records what is bolted on, and seals the openings before the engine is offered. Each listing shows the year, the mileage and the price, so you can compare units side by side.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

Will the M10B18 engine fit my BMW E30 318i?

Yes, if your BMW E30 318i was built with the M10B18. BMW used this 1.8 liter (1,766 cc) petrol engine with 77 kW (105 HP) in the E30 318i from about 1975 to 1988.

Some E30 318i cars were built with a different engine: the M40B18. These look alike from the outside, so check the code on your engine or send us your VIN.

Also tell us if your E30 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines · Search M10B18 in the shop

What is the difference between the M20B25 and other M20 engines?

The M20B25 makes 126 kW (171 HP) and 226 Nm. The other M20 engines are: M20B20 with 95 kW (129 HP) and 174 Nm (1977 to 1992).

Engines in one family share a basic block, but the turbo, the injection, the sensors and the engine computer can differ. A higher power version often has different pistons, a bigger turbo or a different fuel system.

This is why we ask for the exact code. Fitting a different version can work, but the wiring, the software and sometimes the gearbox must be changed to match.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

Will the M20B25 engine fit my BMW E28 525i?

Yes, if your BMW E28 525i was built with the M20B25. BMW used this 2.5 liter (2,494 cc) petrol engine with 126 kW (171 HP) in the E28 525i from about 1985 to 1993.

In our records the M20B25 is the engine for the E28 525i, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E28 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

Will the M20B25 engine fit my BMW E34 525i?

Yes, if your BMW E34 525i was built with the M20B25. BMW used this 2.5 liter (2,494 cc) petrol engine with 126 kW (171 HP) in the E34 525i from about 1985 to 1993.

Some E34 525i cars were built with a different engine: the M50B25. These look alike from the outside, so check the code on your engine or send us your VIN.

Also tell us if your E34 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

Which years were BMW M10 engines made?

BMW built the M10 engines we list from about 1975 to 1988. The M10B18 ran from 1975 to 1988.

They went into chassis E30 and E21. The exact year of a car matters, because BMW sometimes changed the engine version or its parts in the middle of a model's life.

Each listing in our yard names the engine year, so you can match it to the build date of your car.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines

Which cars use the BMW M20B20 engine?

BMW fitted the M20B20 to the BMW E30 320i, BMW E28 520i and BMW E21 320i. These cars were built with this engine from about 1977 to 1992.

The badge on the boot is not enough to be sure. The same model name can hide two different engines, for example after a facelift or a change in emission rules. Always read the engine code stamped on the block, or look it up with your VIN.

Other engines in the same M20 family are the M20B25 (171 HP). They look alike but differ in power, parts and electronics, so they are not always a direct swap.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

What should I replace when I fit a used M10B18 engine?

A used engine lasts longest when it starts life in your car with fresh fluids and new seals. Check the spark plugs and the ignition coils, and make sure the fuel lines are clean and tight before you crank the engine. Fit a new oil filter and fresh oil of the grade BMW lists for this engine, and refill the coolant with the correct BMW antifreeze mix. Use new gaskets for the exhaust manifold, the intake and the sump plug, and check every hose clip before the first start.

Look at the engine mounts and the clutch or the torque converter while the engine is out. Old mounts can crack a new engine's brackets, and a worn clutch is much easier to change now.

Before the first start, turn the engine over without fuel until the oil pressure light goes out. Then let it idle, check for leaks, and drive gently for the first few hundred kilometres.

The warranty asks for fitting by a qualified mechanic and the correct oil, coolant and filters. Keep your receipts in case you ever need to make a claim.

See all M10 Engines · Search M10B18 in the shop

Does a used M20B20 engine come with a warranty?

Yes. Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop.

The warranty does not cover damage from wrong fitting, overheating, low oil, wrong fluids or fuel, engines that were opened or modified without our approval, or labour and towing costs.

To claim, send us your order number, a short description of the problem, photos or a video, and a mechanic's report if we ask for one. If the claim is approved, we repair, replace or refund the engine.

Keep the receipts for the fitting, the oil and the filters. They make any claim quick and simple.

See all M20 Engines · Search M20B20 in the shop

Will the M20B25 engine fit my BMW E30 325is?

Yes, if your BMW E30 325is was built with the M20B25. BMW used this 2.5 liter (2,494 cc) petrol engine with 126 kW (171 HP) in the E30 325is from about 1985 to 1993.

In our records the M20B25 is the engine for the E30 325is, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E30 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

How much is a replacement M20B25 engine for a BMW E30 325is?

A used M20B25 for the BMW E30 325is costs from about 1.300 € to 2.200 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M20B25 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

Does a used M10B18 engine come with a warranty?

Yes. Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop.

The warranty does not cover damage from wrong fitting, overheating, low oil, wrong fluids or fuel, engines that were opened or modified without our approval, or labour and towing costs.

To claim, send us your order number, a short description of the problem, photos or a video, and a mechanic's report if we ask for one. If the claim is approved, we repair, replace or refund the engine.

Keep the receipts for the fitting, the oil and the filters. They make any claim quick and simple.

See all M10 Engines · Search M10B18 in the shop

How long does delivery of an M20B20 engine take?

Orders confirmed before 14:00 CET on a working day leave Hamburg the same day. Later and weekend orders leave the next working day. Delivery to the Netherlands, Belgium, Germany, France, Luxembourg and Denmark takes 1 to 3 working days.

Spain, Italy, Portugal, Poland, Czechia, Austria, Ireland, the Nordics and the Baltics take 2 to 5 working days. Greek and Spanish islands, Malta, Cyprus and remote areas take 4 to 8 working days. The UK and other countries outside the EU are quoted one by one.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Every engine is drained, sealed at each opening, strapped to a heat-treated pallet and shrink-wrapped, then photographed before it leaves the yard.

You get a tracking number when the pallet is collected. Check the wrapping before you sign, and note any damage on the paperwork.

See all M20 Engines · Search M20B20 in the shop

What is the difference between the BMW M20 engines?

BMW M20 small-six petrol engines for E30 and E28. We list 2 versions: M20B25 (2.5 liter (2,494 cc), 126 kW (171 HP), 1985 to 1993); M20B20 (2.0 liter (1,991 cc), 95 kW (129 HP), 1977 to 1992).

The versions share the same basic design, but the power, the turbo or injection set-up, the electronics and the emission standard change. The right one for you is the one your car was built with.

The M20 family was used in chassis E30, E28, E34, Z1 and E21. Each engine in the yard is inspected in Hamburg. The code is matched to the listing, the parts on the engine are recorded, the openings are sealed and the real unit is photographed.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines

How do I know a used M10B18 engine is in good shape?

Before a unit is listed, the yard checks the engine code against the listing, writes down the parts fitted to it, seals every opening and photographs the real engine you will receive. An inspection certificate for the unit can travel with the order when you ask for it.

When you look at a listing, check the recorded mileage, the year and the photos of the ports and the stamp. Ask for photos of anything you want to see closer. You can ask for extra photos, a close-up of the code stamp or a short video before you order.

On a petrol engine like the M10B18, a careful fitter will also look at the spark plugs, the coils and the timing side before the engine goes in.

If the engine fails inside under normal use, the warranty covers you. Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop.

See all M10 Engines · Search M10B18 in the shop

What should I replace when I fit a used M20B25 engine?

A used engine lasts longest when it starts life in your car with fresh fluids and new seals. Fit a new oil filter and fresh oil of the grade BMW lists for this engine, and refill the coolant with the correct BMW antifreeze mix. Change the drive belt, the thermostat and the water pump seals if they look tired, because they are cheap while the engine is out. Use new gaskets for the exhaust manifold, the intake and the sump plug, and check every hose clip before the first start.

Look at the engine mounts and the clutch or the torque converter while the engine is out. Old mounts can crack a new engine's brackets, and a worn clutch is much easier to change now.

Before the first start, turn the engine over without fuel until the oil pressure light goes out. Then let it idle, check for leaks, and drive gently for the first few hundred kilometres.

The warranty asks for fitting by a qualified mechanic and the correct oil, coolant and filters. Keep your receipts in case you ever need to make a claim.

See all M20 Engines · Search M20B25 in the shop

What is the difference between the M20B20 and other M20 engines?

The M20B20 makes 95 kW (129 HP) and 174 Nm. The other M20 engines are: M20B25 with 126 kW (171 HP) and 226 Nm (1985 to 1993).

Engines in one family share a basic block, but the turbo, the injection, the sensors and the engine computer can differ. A higher power version often has different pistons, a bigger turbo or a different fuel system.

This is why we ask for the exact code. Fitting a different version can work, but the wiring, the software and sometimes the gearbox must be changed to match.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

Will the M10B18 engine fit my BMW E30 316?

Yes, if your BMW E30 316 was built with the M10B18. BMW used this 1.8 liter (1,766 cc) petrol engine with 77 kW (105 HP) in the E30 316 from about 1975 to 1988.

In our records the M10B18 is the engine for the E30 316, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E30 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines · Search M10B18 in the shop

How much power and torque does the BMW M10B18 have?

From the factory the BMW M10B18 makes 77 kW (105 HP) and 145 Nm of torque. It is a 1.8 liter (1,766 cc) inline 4, SOHC, 8 valve petrol engine with no turbo (naturally aspirated).

Without a turbo, the power builds smoothly with the revs. A clean air intake, healthy ignition and the correct fuel are key to getting the full figure.

A used engine reaches its factory numbers when it is fitted with the matching engine computer and software, and serviced with the right oil and filters. If the engine computer from your car is a different version, a specialist may need to code it.

Every M10B18 on our site lists its year and mileage. Ask the desk for more pictures of any listing. We are happy to show the stamp, the ports and the ancillaries before you decide.

See all M10 Engines · Search M10B18 in the shop

Will the M20B25 engine fit my BMW Z1?

Yes, if your BMW Z1 was built with the M20B25. BMW used this 2.5 liter (2,494 cc) petrol engine with 126 kW (171 HP) in the Z1 from about 1985 to 1993.

In our records the M20B25 is the engine for the Z1, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your Z1 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

Will the M20B20 engine fit my BMW E30 320i?

Yes, if your BMW E30 320i was built with the M20B20. BMW used this 2.0 liter (1,991 cc) petrol engine with 95 kW (129 HP) in the E30 320i from about 1977 to 1992.

In our records the M20B20 is the engine for the E30 320i, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E30 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

How much power and torque does the BMW M20B25 have?

From the factory the BMW M20B25 makes 126 kW (171 HP) and 226 Nm of torque. It is a 2.5 liter (2,494 cc) inline 6, SOHC, 12 valve petrol engine with no turbo (naturally aspirated).

Without a turbo, the power builds smoothly with the revs. A clean air intake, healthy ignition and the correct fuel are key to getting the full figure.

A used engine reaches its factory numbers when it is fitted with the matching engine computer and software, and serviced with the right oil and filters. If the engine computer from your car is a different version, a specialist may need to code it.

Every M20B25 on our site lists its year and mileage. Ask the desk for more pictures of any listing. We are happy to show the stamp, the ports and the ancillaries before you decide.

See all M20 Engines · Search M20B25 in the shop

How much is a replacement M20B25 engine for a BMW E30 325i?

A used M20B25 for the BMW E30 325i costs from about 1.300 € to 2.200 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M20B25 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

How do I know a used M20B25 engine is in good shape?

Before a unit is listed, the yard checks the engine code against the listing, writes down the parts fitted to it, seals every opening and photographs the real engine you will receive. An inspection certificate for the unit can travel with the order when you ask for it.

When you look at a listing, check the recorded mileage, the year and the photos of the ports and the stamp. Ask for photos of anything you want to see closer. Ask the desk for more pictures of any listing. We are happy to show the stamp, the ports and the ancillaries before you decide.

On a petrol engine like the M20B25, a careful fitter will also look at the spark plugs, the coils and the timing side before the engine goes in.

If the engine fails inside under normal use, the warranty covers you. Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop.

See all M20 Engines · Search M20B25 in the shop

How much is a replacement M20B25 engine for a BMW E28 525i?

A used M20B25 for the BMW E28 525i costs from about 1.300 € to 2.200 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M20B25 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

Will the M20B20 engine fit my BMW E28 520i?

Yes, if your BMW E28 520i was built with the M20B20. BMW used this 2.0 liter (1,991 cc) petrol engine with 95 kW (129 HP) in the E28 520i from about 1977 to 1992.

In our records the M20B20 is the engine for the E28 520i, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E28 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

How much is a replacement M20B20 engine for a BMW E30 320i?

A used M20B20 for the BMW E30 320i costs from about 1.000 € to 1.700 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M20B20 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

What comes with a used M20B25 engine?

Each M20B25 is sold as described on its own listing. The yard writes down the parts that are fitted to that unit, such as the turbo, the injectors, the manifolds or the alternator, so you know what arrives.

Some units are long engines with few ancillaries, others are more complete. If you need a part that is not listed, ask the desk. We often have the matching items in the yard.

Every engine is drained, sealed at each opening, strapped to a heat-treated pallet and shrink-wrapped, then photographed before it leaves the yard.

On delivery, the carrier brings the pallet to the kerb or a loading bay. Please have a forklift, a pallet truck or an engine crane ready.

See all M20 Engines · Search M20B25 in the shop

What is the BMW M20B25 engine?

The BMW M20B25 is a 2.5 liter (2,494 cc) petrol engine from the M20 family. It has an inline 6, SOHC, 12 valve layout with no turbo (naturally aspirated), and makes 126 kW (171 HP) with 226 Nm of torque. BMW built it from 1985 to 1993 and it meets the Euro 1 emission standard.

You find the M20B25 in the BMW E30 325i, BMW E30 325is, BMW E28 525i, BMW E34 525i and BMW Z1. What we list: BMW M20 small-six petrol engines for E30 and E28.

At Autowerke Engines every M20B25 is a real used engine from our yard in Hamburg. The photos on each listing show the actual engine, not a stock picture. The yard checks the code, records what is bolted on, and seals the openings before the engine is offered. Each listing shows the year, the mileage and the price, so you can compare units side by side.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

How much is a replacement M20B20 engine for a BMW E28 520i?

A used M20B20 for the BMW E28 520i costs from about 1.000 € to 1.700 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M20B20 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B20 in the shop

How much is a replacement M20B25 engine for a BMW E34 525i?

A used M20B25 for the BMW E34 525i costs from about 1.300 € to 2.200 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M20B25 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M20 Engines · Search M20B25 in the shop

What is the BMW M10B18 engine?

The BMW M10B18 is a 1.8 liter (1,766 cc) petrol engine from the M10 family. It has an inline 4, SOHC, 8 valve layout with no turbo (naturally aspirated), and makes 77 kW (105 HP) with 145 Nm of torque. BMW built it from 1975 to 1988 and it meets the Euro 1 emission standard.

You find the M10B18 in the BMW E30 316, BMW E30 318i, BMW E21 316 and BMW E21 318i. What we list: BMW M10 four-cylinder petrol engines for E30 316 and E21.

At Autowerke Engines every M10B18 is a real used engine from our yard in Hamburg. The photos on each listing show the actual engine, not a stock picture. The yard checks the code, records what is bolted on, and seals the openings before the engine is offered. Each listing shows the year, the mileage and the price, so you can compare units side by side.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M10 Engines · Search M10B18 in the shop

Glossary

• 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.
• Timing chain tensioner — A hydraulic or spring device that keeps the timing chain tight. Worn tensioners cause cold-start rattle.
• 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.

Our verdict

The Classic BMW 02, E3, E9 and E21 offers a wide choice of engines, and the right replacement depends on your exact model, build date and gearbox. Confirm the code with your VIN, choose a unit with known history, replace the known weak parts while it is out, and the car will be back on the road for years.

See every Classic BMW 02, E3, E9 and E21 engine in stock, or ask the Hamburg desk to check your VIN.