BMW built the M42B18 from 1989 to 1996. It is a 1.8 L naturally aspirated petrol inline-4 with 140 hp and 175 Nm, part of the M42 family. You will find it in the BMW E30 318is and BMW E36 318is.
This guide is about the M42B18 specifically: its specification, the cars that use it, how it differs from the other M42 versions, what to check, prices from our stock and fitment answers for each model. For the history of the whole family, read our M42 and M44 guide.
- Capacity and layout: 1.8 L, inline-4, naturally aspirated
- Output: 140 hp and 175 Nm
- Production: 1989–1996
- Fitted to: 2 models across 2 chassis generations
- In our stock: ask the desk for the next arrival
M42B18 specifications
| Item | Value |
|---|---|
| Engine code | M42B18 |
| Family | M42 |
| Capacity | 1.8 L |
| Layout | Inline-4 |
| Fuel | Petrol |
| Aspiration | Naturally aspirated |
| Power | 140 hp |
| Torque | 175 Nm |
| Specific output | 78 hp per litre |
| Production | 1989–1996 |
| Models | 2 |
Built from 1989 to 1996, the M42B18 displaces 1.8 L in an inline-4 layout and is naturally aspirated. It produces 140 hp and 175 Nm on petrol. That is about 78 hp and 97 Nm per litre, a strong figure for a road engine of its era. It was fitted to the BMW E30 318is and BMW E36 318is.
What the code M42B18 means
- M marks an M-series code, the naming BMW used for its engine families up to the early 2000s.
- 42 is the family number.
- B stands for petrol (from the German Benzin).
- 18 is the capacity in decilitres, so 1.8 litres.
Which BMW models use the M42B18
| Model | Generation | Built |
|---|---|---|
| BMW E30 318is | second 3 Series | 1982–1994 |
| BMW E36 318is | third 3 Series | 1990–2000 |
In the E30 second 3 Series (1982–1994), the M42B18 powered the 318is. 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 E36 third 3 Series (1990–2000), the M42B18 powered the 318is. Engines from other models fit the E36 as long as the sump, mounts and ancillaries match, which we check against your VIN. All E36 engines
Common M42B18 problems
The M42B18 shares its weak points with the rest of the M42 family. These are the faults to check on a used unit and on your own engine. The full explanation of each is in the M42 and M44 guide.
| Known fault | What to check |
|---|---|
| Head gasket | Check for mayonnaise under the oil cap and for coolant loss without visible leaks. |
| Timing chain guides and tensioner | Listen at the front of the engine on a cold start. |
| Valve cover and oil leaks | Pull a coil or plug lead and look for oil. |
| Plastic cooling parts | Look for white coolant stains and check the water pump impeller type. |
Valve cover and oil leaks. Valve cover and spark plug tube gaskets harden and leak oil into the plug wells.
M42B18 maintenance
- 10W-40 or 5W-40 synthetic, about 4.5 litres with filter.
- Oil every 10,000 km; cooling system parts every 80,000 to 100,000 km.
- Timing chain at the front with guides and a hydraulic tensioner.
Will the M42B18 fit my car?
M42B18 prices
We do not have an M42B18 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 M42B18: checklist
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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 M42B18
How much is a replacement M42B18 engine for a BMW E36 318is?
A used M42B18 for the BMW E36 318is costs from about 1.150 € to 1.950 € 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 M42B18 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 M42 Engines · Search M42B18 in the shop
How much is a replacement M42B18 engine for a BMW E36 318i?
A used M42B18 for the BMW E36 318i costs from about 1.150 € to 1.950 € 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 M42B18 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 M42 Engines · Search M42B18 in the shop
Are there other versions of the BMW M42B18?
In our yard the M42B18 is the only listed version of the M42 family. It makes 100 kW (136 HP) and 172 Nm, and was built from 1989 to 1996.
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 M42 Engines · Search M42B18 in the shop
How much does a used BMW M42B18 engine cost?
A used BMW M42B18 engine in our yard usually costs between 1.150 € and 1.950 €. 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.
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What is the BMW M42B18 engine?
The BMW M42B18 is a 1.8 liter (1,796 cc) petrol engine from the M42 family. It has an inline 4, DOHC, 16 valve layout with no turbo (naturally aspirated), and makes 100 kW (136 HP) with 172 Nm of torque. BMW built it from 1989 to 1996 and it meets the Euro 1 emission standard.
You find the M42B18 in the BMW E30 318is, BMW E36 318i and BMW E36 318is. What we list: BMW M42 1.8 16-valve engines for E30 318is and E36 318i.
At Autowerke Engines every M42B18 is a real used engine from our yard in Hamburg. 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. 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 M42 Engines · Search M42B18 in the shop
Is the BMW M42B18 a diesel or petrol engine?
The M42B18 is a petrol engine. It is a 1.8 liter (1,796 cc) inline 4, DOHC, 16 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 M42 Engines · Search M42B18 in the shop
Will the M42B18 engine fit my BMW E36 318i?
Yes, if your BMW E36 318i was built with the M42B18. BMW used this 1.8 liter (1,796 cc) petrol engine with 100 kW (136 HP) in the E36 318i from about 1989 to 1996.
Some E36 318i cars were built with a different engine: the M40B18 and M43B18. These look alike from the outside, so check the code on your engine or send us your VIN.
Also tell us if your E36 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 M42 Engines · Search M42B18 in the shop
How long does delivery of an M42B18 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 M42 Engines · Search M42B18 in the shop
Can you check if an M42B18 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 M42B18, we confirm that your car was built with this code or with a version that can take it. BMW used it in the BMW E30 318is, BMW E36 318i and BMW E36 318is.
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 M42 Engines · Search M42B18 in the shop
Does a used M42B18 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 M42 Engines · Search M42B18 in the shop
How much power and torque does the BMW M42B18 have?
From the factory the BMW M42B18 makes 100 kW (136 HP) and 172 Nm of torque. It is a 1.8 liter (1,796 cc) inline 4, DOHC, 16 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 M42B18 on our site lists its year and mileage. You can ask for extra photos, a close-up of the code stamp or a short video before you order.
See all M42 Engines · Search M42B18 in the shop
Will the M42B18 engine fit my BMW E36 318is?
Yes, if your BMW E36 318is was built with the M42B18. BMW used this 1.8 liter (1,796 cc) petrol engine with 100 kW (136 HP) in the E36 318is from about 1989 to 1996.
In our records the M42B18 is the engine for the E36 318is, which makes the match simple. Still, check the code on your old engine or send us your VIN.
Also tell us if your E36 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 M42 Engines · Search M42B18 in the shop
What comes with a used M42B18 engine?
Each M42B18 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 M42 Engines · Search M42B18 in the shop
What should I replace when I fit a used M42B18 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 M42 Engines · Search M42B18 in the shop
Will the M42B18 engine fit my BMW E30 318is?
Yes, if your BMW E30 318is was built with the M42B18. BMW used this 1.8 liter (1,796 cc) petrol engine with 100 kW (136 HP) in the E30 318is from about 1989 to 1996.
In our records the M42B18 is the engine for the E30 318is, 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 M42 Engines · Search M42B18 in the shop
Which cars use the BMW M42B18 engine?
BMW fitted the M42B18 to the BMW E30 318is, BMW E36 318i and BMW E36 318is. These cars were built with this engine from about 1989 to 1996.
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.
The M42B18 is the only M42 version we list, which makes it easy to pick, but the wiring and the engine computer still need to match 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 M42 Engines · Search M42B18 in the shop
How do I know a used M42B18 engine is in good shape?
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. 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 M42B18, 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 M42 Engines · Search M42B18 in the shop
How much is a replacement M42B18 engine for a BMW E30 318is?
A used M42B18 for the BMW E30 318is costs from about 1.150 € to 1.950 € 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 M42B18 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 M42 Engines · Search M42B18 in the shop
Delivery, warranty and payment
Before an M42B18 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.
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.
M42 and M44 engine guide · All M42 and M44 engines · Send us your VIN
