The M502 is a 2.6 L petrol V8 from BMW's M50 family, built 1954–1961 and rated at 100 hp and 180 Nm. It powered the BMW 502 2.6 and BMW 503 2.6.
This guide is about the M502 specifically: its specification, the cars that use it, how it differs from the other M50 versions, what to check, prices from our stock and fitment answers for each model. For the history of the whole family, read our M50 guide.
- Capacity and layout: 2.6 L, V8, naturally aspirated
- Output: 100 hp and 180 Nm
- Production: 1954–1961
- Fitted to: 2 models across 0 chassis generations
- In our stock: 3 units from 2.603,00 €
M502 specifications
| Item | Value |
|---|---|
| Engine code | M502 |
| Family | M50 |
| Capacity | 2.6 L |
| Layout | V8 |
| Fuel | Petrol |
| Aspiration | Naturally aspirated |
| Power | 100 hp |
| Torque | 180 Nm |
| Specific output | 38 hp per litre |
| Production | 1954–1961 |
| Models | 2 |
M502: 2.6 L, V8, petrol, naturally aspirated. Output is 100 hp with 180 Nm of torque, and production ran from 1954 to 1961. That is about 38 hp and 69 Nm per litre, a relaxed tune aimed at torque, durability and economy. Within the M50 family, the M503 (140 hp), M507 (150 hp) and M50B20 (150 hp) are more powerful. It was fitted to the BMW 502 2.6 and BMW 503 2.6.
M502 compared with other M50 versions
| Code | Capacity | Power | Torque | Years |
|---|---|---|---|---|
| M502 | 2.6 L | 100 hp | 180 Nm | 1954–1961 |
| M503 | 3.2 L | 140 hp | 240 Nm | 1956–1959 |
| M507 | 3.2 L | 150 hp | 240 Nm | 1956–1959 |
| M50B20 | 2.0 L | 150 hp | 190 Nm | 1990–1996 |
| M50B25 | 2.5 L | 192 hp | 245 Nm | 1990–1996 |
| M50TUB20 | 2.0 L | 150 hp | 190 Nm | 1992–1995 |
| M50TUB25 | 2.5 L | 192 hp | 245 Nm | 1992–1995 |
M502 or M503?
The M503 has 40 hp more than the M502 (140 against 100 hp), from 3.2 L instead of 2.6 L, and was built 1956–1959. 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.
M502 or M507?
The M507 has 50 hp more than the M502 (150 against 100 hp), from 3.2 L instead of 2.6 L, and was built 1956–1959. 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.
M502 or M50B20?
The M50B20 has 50 hp more than the M502 (150 against 100 hp), from 2.0 L instead of 2.6 L, and was built 1990–1996. 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 M502 problems
The M502 shares its weak points with the rest of the M50 family. These are the faults to check on a used unit and on your own engine. The full explanation of each is in the M50 guide.
| Known fault | What to check |
|---|---|
| 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. |
Valve cover gasket. A common leak that also lets oil into the spark plug wells.
M502 maintenance
- 5W-40 or 10W-40 synthetic, about 6.5 litres with filter.
- Oil every 10,000 to 15,000 km; cooling system as a set every 100,000 km.
- Duplex lower chain and single upper chain at the front with hydraulic tensioner.
M502 prices
We currently hold 3 M502 engines. The cheapest is 2.603,00 €, the most expensive 2.728,00 €, and half of them cost less than 2.709,00 €.
Prices depend on the exact version, the donor's mileage, how complete the engine is and the demand for that code. Higher-output versions, low mileage and dressed engines with turbo, injectors and ancillaries cost more; long blocks and higher mileage cost less.
M502 engines in stock
Here is a selection of M502 engines currently on our shelves, photographed in the yard. Click any of them for the full photographs, mileage and specification.
BMW 503 2.6 M502 Complete Engine2.709,00 €
BMW 502 2.6 M502 Complete Engine2.603,00 €
BMW M502 Engine2.728,00 €BMW 503 2.6 M502 Complete Engine — 2.709,00 €, reduced from 3.200,00 €. It comes from a recorded donor car, and 10 units are available. Ask the desk for compression figures or extra photographs before you order.
BMW 502 2.6 M502 Complete Engine — 2.603,00 €, reduced from 3.200,00 €. It comes from a recorded donor car, and 22 units are available. The listing shows every side of the engine and the fitted parts.
BMW M502 Engine — 2.728,00 €, reduced from 3.200,00 €. It comes from a recorded donor car, and 29 units are available. The listing shows every side of the engine and the fitted parts.
Buying a used M502: checklist
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Plastic cooling parts. Expansion tanks, thermostat housings and water pump impellers made of plastic crack with age. Plan to replace them when the engine is fitted.
Questions about the M502
Which years were BMW M50 engines made?
BMW built the M50 engines we list from about 1990 to 1995. The M50B25 ran from 1990 to 1995. The M50B20 ran from 1990 to 1995.
They went into chassis E36, E34 and Z3. 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.
What is the difference between the BMW M50 engines?
BMW M50 24-valve petrol engines for E36 320i and 325i. We list 2 versions: M50B25 (2.5 liter (2,494 cc), 141 kW (192 HP), 1990 to 1995); M50B20 (2.0 liter (1,991 cc), 110 kW (150 HP), 1990 to 1995).
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 M50 family was used in chassis E36, E34 and Z3. 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.
What should I check on a used BMW M50 engine?
Start with the basics: the engine code on the block, the recorded mileage and the photos. Make sure the code matches your car and the parts you need are on the unit.
On an M50 petrol engine, a fitter usually checks the spark plugs, the coils, the timing side and the oil seals. These parts are easy to check before fitting and easy to change if needed.
You can ask for extra photos, a close-up of the code stamp or a short video before you order. An inspection certificate can travel with the order on request.
Once fitted, change the oil and filter early and drive gently at first. Report any problem right away so the warranty stays valid.
See all M50 Engines · Inspection certificate
What should I replace when I fit a used M50B20 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. Check the spark plugs and the ignition coils, and make sure the fuel lines are clean and tight before you crank the engine. Change the drive belt, the thermostat and the water pump seals if they look tired, because they are cheap while the engine is out.
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 M50 Engines · Search M50B20 in the shop
How much power and torque does the BMW M50B25 have?
From the factory the BMW M50B25 makes 141 kW (192 HP) and 245 Nm of torque. It is a 2.5 liter (2,494 cc) inline 6, DOHC, 24 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 M50B25 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 M50 Engines · Search M50B25 in the shop
How do I know a used M50B25 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 M50B25, 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 M50 Engines · Search M50B25 in the shop
How much is a replacement M50B20 engine for a BMW E36 320i?
A used M50B20 for the BMW E36 320i 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 M50B20 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 M50 Engines · Search M50B20 in the shop
Is the BMW M50B20 a diesel or petrol engine?
The M50B20 is a petrol engine. It is a 2.0 liter (1,991 cc) inline 6, DOHC, 24 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 M50 Engines · Search M50B20 in the shop
How much power and torque does the BMW M50B20 have?
From the factory the BMW M50B20 makes 110 kW (150 HP) and 190 Nm of torque. It is a 2.0 liter (1,991 cc) inline 6, DOHC, 24 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 M50B20 on our site lists its year and mileage. If you want more photos or a short video of a unit, ask the desk and we send them before you pay.
See all M50 Engines · Search M50B20 in the shop
Can you check if an M50B20 fits my car with my VIN?
Yes, and it is free. Send the 17-character VIN of your car and, if you have it, the gearbox code. We check the engine family, the build year window and the parts your car needs.
For the M50B20, we confirm that your car was built with this code or with a version that can take it. BMW used it in the BMW E36 320i and BMW E34 520i.
We only reserve an engine once the match is confirmed, so you never pay for the wrong unit. You can reach the Hamburg desk by email at autowerkeengines@gmail.com, or by phone and WhatsApp on +49 15510 030835, Monday to Friday, 9:00 to 16:00 CET.
You can also use the VIN check on our site. It reads the year, the make, the model and the engine from the public vehicle register.
See all M50 Engines · Search M50B20 in the shop
Will the M50B20 engine fit my BMW E34 520i?
Yes, if your BMW E34 520i was built with the M50B20. BMW used this 2.0 liter (1,991 cc) petrol engine with 110 kW (150 HP) in the E34 520i from about 1990 to 1995.
In our records the M50B20 is the engine for the E34 520i, which makes the match simple. Still, check the code on your old 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 M50 Engines · Search M50B20 in the shop
Can you check if an M50B25 fits my car with my VIN?
Yes, and it is free. Send the 17-character VIN of your car and, if you have it, the gearbox code. We check the engine family, the build year window and the parts your car needs.
For the M50B25, we confirm that your car was built with this code or with a version that can take it. BMW used it in the BMW E36 325i, BMW E34 525i and BMW Z3 2.5.
We only reserve an engine once the match is confirmed, so you never pay for the wrong unit. You can reach the Hamburg desk by email at autowerkeengines@gmail.com, or by phone and WhatsApp on +49 15510 030835, Monday to Friday, 9:00 to 16:00 CET.
You can also use the VIN check on our site. It reads the year, the make, the model and the engine from the public vehicle register.
See all M50 Engines · Search M50B25 in the shop
Delivery, warranty and payment
Before an M502 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.
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.
