The BMW 318is in the second 3 Series generation (E30, built 1982–1994) was built with one engine, the M42B18: a 1.8 L petrol inline-4 with 140 hp.
Below you will find how to identify the engine in your 318is, the faults to look for, current prices for a replacement and the swap options that make sense.
- Generation: second 3 Series, 1982–1994
- Body styles: E30 (saloon, Touring, coupé, convertible)
- Engines: M42B18
- Output: 140 hp
- Replacement engines in stock: ask the desk for the next arrival
Which engine is in your 318is?
| Engine code | Built | Power | Torque | Type |
|---|---|---|---|---|
| M42B18 | 1989–1996 | 140 hp | 175 Nm | 1.8 L petrol inline-4, naturally aspirated |
M42B18 in the 318is
The M42B18 was used in the E30 318is, built 1989–1996. It is a 1.8 L naturally aspirated petrol inline-4 with 140 hp and 175 Nm.
Reading the code: 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.
318is engines by model year
| Model year | Engine |
|---|---|
| 1989 | M42B18 (140 hp) |
| 1990 | M42B18 (140 hp) |
| 1991 | M42B18 (140 hp) |
| 1992 | M42B18 (140 hp) |
| 1993 | M42B18 (140 hp) |
| 1994 | M42B18 (140 hp) |
The 318is kept the same engine for the whole E30 run, which makes ordering simple: any unit with the same code fits, subject to the gearbox, drive type and sump.
Other cars with the same engine as the 318is
A replacement engine does not have to come from another 318is. These models left the factory with the same engine code, so a unit from any of them is a candidate donor once the sump, mounts and ancillaries are matched to your car.
M42B18: BMW E36 318is.
How to confirm your engine code
The 318is only used the M42B18, but the exact version can still change with the build date, gearbox and market. Send us the last seven characters of the VIN and we read the engine code from BMW's records, or look for the code stamped on the block. How to find your BMW engine code.
Known 318is engine problems
The M42B18 in the 318is shares the known weak points of the M42 and M44 family. Full 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. |
Head gasket. The M42 is known for head gasket failures, often showing as coolant loss into a cylinder or oil in the coolant. The later gasket design improved this.
Timing chain guides and tensioner. Guide rails and the tensioner wear, leading to chain noise on start-up.
Valve cover and oil leaks. Valve cover and spark plug tube gaskets harden and leak oil into the plug wells.
Plastic cooling parts. E36-era thermostat housings, expansion tanks and water pump impellers crack with age.
Symptoms to watch for on the 318is
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.
Looking after the 318is engine
- Oil: 10W-40 or 5W-40 synthetic, about 4.5 litres with filter.
- Service interval: Oil every 10,000 km; cooling system parts every 80,000 to 100,000 km.
- Timing drive: Timing chain at the front with guides and a hydraulic tensioner.
- Workshop notes: Hydraulic lifters mean no valve adjustment, but they need clean oil of the right viscosity to stay quiet.
Buying a used engine for the 318is: checklist
- 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.
- 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.
- 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.
- 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.
- 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.
BMW 318is replacement engine cost
We do not have a 318is engine on the shelf at the moment. Send us your VIN or the code you need and the desk will tell you when the next unit arrives and what it will cost.
On top of the engine, budget for the workshop's labour and the parts that are best replaced while the engine is out: engine mounts, the rear main seal, cooling parts, a clutch or converter seal, fluids and filters.
Will it fit my 318is?
Engine swaps and upgrades for the 318is
These engines were fitted to other versions of the E30 at the factory, which makes them the most practical upgrades: the body was designed around them and many parts are shared.
| Engine | Factory model | Power | Gain |
|---|---|---|---|
| M20B25 | E30 325i | 170 hp | +30 hp |
| S14B20 | E30 320iS | 192 hp | +52 hp |
| S14B23 | E30 M3 | 200 hp | +60 hp |
Can I fit the M20B25 in my 318is?
It is a conversion rather than a replacement: the M20B25 is an inline-6 and your M42B18 an inline-4, so mounts, sump, cooling, exhaust, wiring and the engine control unit all change. The gain is 30 hp and 51 Nm. In Germany and most of Europe an engine swap must be inspected and registered.
Can I fit the S14B20 in my 318is?
Yes, it is one of the more common upgrades. Both are petrol inline-4 engines, so the mounting points are similar, but the S14B20 needs its own wiring and engine control unit, the matching gearbox or clutch, and often a different sump, cooling and exhaust. The gain is 52 hp and 35 Nm. In Germany and most of Europe an engine swap must be inspected and registered.
Can I fit the S14B23 in my 318is?
Yes, it is one of the more common upgrades. Both are petrol inline-4 engines, so the mounting points are similar, but the S14B23 needs its own wiring and engine control unit, the matching gearbox or clutch, and often a different sump, cooling and exhaust. The gain is 60 hp and 65 Nm. In Germany and most of Europe an engine swap must be inspected and registered.
Fitting a replacement engine in the 318is
- 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.
- 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.
- 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.
- 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.
- First 1,000 km. Drive gently for the first few hundred kilometres, vary the engine speed and avoid full load. Change the oil and filter after about 1,000 km to remove any assembly debris.
The full fitting and first-start procedure.
318is engine questions
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
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
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
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
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
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.
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
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
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
Delivery, warranty and payment
Every 318is 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.
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.
All E30 engines · M42 and M44 engine guide · Send us your VIN
