The M20B27 is a 2.7 L petrol inline-6 from BMW's M20 family, built 1982–1988 and rated at 125 hp and 240 Nm. It powered the BMW E30 325e and BMW E28 525e.
This guide is about the M20B27 specifically: its specification, the cars that use it, how it differs from the other M20 versions, what to check, prices from our stock and fitment answers for each model. For the history of the whole family, read our M20 guide.
- Capacity and layout: 2.7 L, inline-6, naturally aspirated
- Output: 125 hp and 240 Nm
- Production: 1982–1988
- Fitted to: 2 models across 2 chassis generations
- In our stock: ask the desk for the next arrival
M20B27 specifications
| Item | Value |
|---|---|
| Engine code | M20B27 |
| Family | M20 |
| Capacity | 2.7 L |
| Layout | Inline-6 |
| Fuel | Petrol |
| Aspiration | Naturally aspirated |
| Power | 125 hp |
| Torque | 240 Nm |
| Specific output | 46 hp per litre |
| Production | 1982–1988 |
| Models | 2 |
The M20B27 is a 2.7 L inline-6 petrol engine, naturally aspirated, rated at 125 hp and 240 Nm. BMW built it from 1982 to 1988. That is about 46 hp and 89 Nm per litre, a relaxed tune aimed at torque, durability and economy. Within the M20 family, the M20B20 (129 hp), M20B23 (139 hp) and M20B25 (170 hp) are more powerful. It was fitted to the BMW E30 325e and BMW E28 525e.
What the code M20B27 means
- M marks an M-series code, the naming BMW used for its engine families up to the early 2000s.
- 20 is the family number.
- B stands for petrol (from the German Benzin).
- 27 is the capacity in decilitres, so 2.7 litres.
Which BMW models use the M20B27
| Model | Generation | Built |
|---|---|---|
| BMW E30 325e | second 3 Series | 1982–1994 |
| BMW E28 525e | second 5 Series | 1981–1988 |
In the E30 second 3 Series (1982–1994), the M20B27 powered the 325e. Engines from other models fit the E30 as long as the sump, mounts and ancillaries match, which we check against your VIN. All E30 engines
In the E28 second 5 Series (1981–1988), the M20B27 powered the 525e. Engines from other models fit the E28 as long as the sump, mounts and ancillaries match, which we check against your VIN. All E28 engines
M20B27 compared with other M20 versions
| Code | Capacity | Power | Torque | Years |
|---|---|---|---|---|
| M20B20 | 2.0 L | 129 hp | 164 Nm | 1977–1992 |
| M20B23 | 2.3 L | 139 hp | 205 Nm | 1977–1987 |
| M20B27 | 2.7 L | 125 hp | 240 Nm | 1982–1988 |
| M20B25 | 2.5 L | 170 hp | 226 Nm | 1985–1993 |
M20B27 or M20B20?
The M20B20 has 4 hp more than the M20B27 (129 against 125 hp), from 2.0 L instead of 2.7 L, and was built 1977–1992. A different capacity means a different crankshaft, pistons or head, and different software. It can be fitted as an upgrade with the matching engine control unit and wiring, but it is a conversion rather than a straight replacement.
M20B27 or M20B23?
The M20B23 has 14 hp more than the M20B27 (139 against 125 hp), from 2.3 L instead of 2.7 L, and was built 1977–1987. A different capacity means a different crankshaft, pistons or head, and different software. It can be fitted as an upgrade with the matching engine control unit and wiring, but it is a conversion rather than a straight replacement.
M20B27 or M20B25?
The M20B25 has 45 hp more than the M20B27 (170 against 125 hp), from 2.5 L instead of 2.7 L, and was built 1985–1993. A different capacity means a different crankshaft, pistons or head, and different software. It can be fitted as an upgrade with the matching engine control unit and wiring, but it is a conversion rather than a straight replacement.
Common M20B27 problems
The M20B27 shares its weak points with the rest of the M20 family. These are the faults to check on a used unit and on your own engine. The full explanation of each is in the M20 guide.
| Known fault | What to check |
|---|---|
| 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. |
Oil spray bar and cam wear. A loose or blocked spray bar starves the cam lobes. The result is a worn cam and noisy valve train.
M20B27 maintenance
- 10W-40 or 15W-40 semi-synthetic, about 4.25 litres with filter.
- Oil every 7,500 km; valve clearances every 15,000 km; belt on time, not only on distance.
- Rubber timing belt with tensioner, changed with the water pump every 60,000 km or four years.
Will the M20B27 fit my car?
Will the M20B27 fit my BMW E30 325e?
For the BMW E30 325e, the M20B27 is the factory engine and the one to order. The second 3 Series was built 1982–1994, and the M20B27 was produced 1982–1988, 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 E30 325e?
We do not have an M20B27 on the shelf for the E30 325e 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 M20B27 fit my BMW E28 525e?
The M20B27 is the original engine for the BMW E28 525e, which makes it the straightforward choice. The second 5 Series was built 1981–1988, and the M20B27 was produced 1982–1988, 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 E28 525e?
We do not have an M20B27 on the shelf for the E28 525e 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.
M20B27 prices
We do not have an M20B27 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.
Buying a used M20B27: checklist
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
Questions about the M20B27
Which years were BMW M20 engines made?
BMW built the M20 engines we list from about 1977 to 1993. The M20B25 ran from 1985 to 1993. The M20B20 ran from 1977 to 1992.
They went into chassis E30, E28, E34, Z1 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.
How long does delivery of an M20B25 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 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
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 does a used BMW M20B20 engine cost?
A used BMW M20B20 engine in our yard usually costs between 1.000 € and 1.700 €. The exact price depends on the year, the mileage and the parts that come with the engine.
Our units show recorded mileage from about 22,000 km up to around 200,000 km. Lower mileage and more ancillaries mean a higher price. Each listing shows its own price, and the price you see is the price you pay. Prices include VAT for private buyers.
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. If you order a gearbox or a second engine on the same order, the fee is still charged once.
Inside the EU there is no import duty. For the UK and other non-EU countries, import duty and local VAT are paid by the receiver, and we supply a commercial invoice.
See all M20 Engines · Search M20B20 in the shop
How much does a used BMW M20B25 engine cost?
A used BMW M20B25 engine in our yard usually costs between 1.300 € and 2.200 €. The exact price depends on the year, the mileage and the parts that come with the engine.
Our units show recorded mileage from about 22,000 km up to around 200,000 km. Lower mileage and more ancillaries mean a higher price. Each listing shows its own price, and the price you see is the price you pay. Prices include VAT for private buyers.
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. If you order a gearbox or a second engine on the same order, the fee is still charged once.
Inside the EU there is no import duty. For the UK and other non-EU countries, import duty and local VAT are paid by the receiver, and we supply a commercial invoice.
See all M20 Engines · Search M20B25 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 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.
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 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
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
Which cars use the BMW M20B25 engine?
BMW fitted the M20B25 to the BMW E30 325i, BMW E30 325is, BMW E28 525i, BMW E34 525i and BMW Z1. These cars were built with this engine from about 1985 to 1993.
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 M20B20 (129 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 M20B25 in the shop
Delivery, warranty and payment
Every M20B27 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.
Delivery is door to door and included in the price. Most European addresses receive the engine within five to ten working days; Germany and its neighbours are usually faster.
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.
