BMW 118i (F40) engine: which one, problems and replacement

The BMW 118i in the third 1 Series generation (F40, built 2019–) was built with 2 different engines over its life: the B38B15 (136 hp, 2014–2026) and the B38A15 (136 hp, 2014–2024).

This guide tells you which engine your 118i has, what goes wrong with it, what a replacement costs from our stock and what else to plan for when you fit one.

• Generation: third 1 Series, 2019–
• Body styles: F40 (hatchback)
• Engines: B38B15, B38A15
• Output: 136 hp
• Replacement engines in stock: 137 from 1.275,00 €

Which engine is in your 118i?

B38B15 in the 118i

The B38B15 was used in the F40 118i, built 2014–2026. It is a 1.5 L turbocharged petrol inline-3 with 136 hp and 220 Nm. It has the same output as the B38A15, so the build date decides which one your car has.

Reading the code: B marks a B-series code, BMW's modular engine family introduced from 2013 with 500 cc per cylinder; 38 is the family number; B stands for petrol, longitudinal installation for rear-drive and xDrive cars; 15 is the capacity in decilitres, so 1.5 litres.

B38A15 in the 118i

The B38A15 was used in the F40 118i, built 2014–2024. It is a 1.5 L turbocharged petrol inline-3 with 136 hp and 220 Nm. It has the same output as the B38B15, so the build date decides which one your car has.

Reading the code: B marks a B-series code, BMW's modular engine family introduced from 2013 with 500 cc per cylinder; 38 is the family number; A stands for petrol, transverse installation for front-drive cars; 15 is the capacity in decilitres, so 1.5 litres.

Other cars with the same engine as the 118i

A replacement engine does not have to come from another 118i. 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.

B38B15: BMW F45 218i, BMW G20 318i, MINI F56 Mini Cooper.

B38A15: MINI F56 Cooper, BMW F45 218i.

How to confirm your engine code

Because the 118i used more than one engine, the badge alone does not tell you which one your car has. The build date is the first clue; the VIN is the proof. 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 118i engine problems

The B38B15 and B38A15 in the 118i share the known weak points of the B38 family. Full B38 guide.

Coolant leaks. Thermostat housings and coolant pipes leak.

Ignition coils. Coils fail and cause misfires.

Engine mounts. Three-cylinder vibration finishes mounts.

Carbon build-up. Intake valves carbon up over time.

Symptoms to watch for on the 118i

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.

Rattle or whine from the gearbox end. On engines with the timing chain at the rear, a rattle or whine from the back of the engine is the warning sign of chain stretch or guide wear.

Whistle, loss of boost or limp mode. A split charge pipe, a sticking wastegate or worn turbo bearings. Check the pipes first, then the turbo shaft for play.

Poor low-down torque and uneven idle. VANOS seals or solenoids. The engine may run well at high revs but feel flat and lumpy at low speed.

Limp mode with a Valvetronic fault. The Valvetronic motor, its eccentric shaft sensor or the wiring. The engine runs on a reduced throttle until it is repaired.

Long cranking before the engine starts. On direct-injection engines, a weak high-pressure fuel pump or leaking injector lets pressure drop when the engine is off.

Looking after the 118i engine

• Oil: 0W-20 or 0W-30 BMW Longlife-17 FE+ or 01, about 4.25 litres.
• Service interval: Oil every 15,000 km or yearly.
• Timing drive: Timing chain at the rear (gearbox end).
• Workshop notes: Front-drive (B38A) and rear-drive (B38B) versions are not interchangeable without changes.

Buying a used engine for the 118i: checklist

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. Turbocharger shaft play and oil. Rotate the compressor wheel by hand. A small amount of side play is normal; in-and-out play or wheel contact with the housing is not. Oil pooled in the intake or intercooler pipes points to worn seals.
7. 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.
8. Gearbox-end timing chain. On this engine the timing chain sits at the gearbox end, so replacing it normally means removing the engine. If the chain has not been replaced, the time to do it is before the engine goes into your car.
9. 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.
10. Double VANOS units and solenoids. Ask for the adaptation values or fault history if the engine was running. Solenoids are inexpensive and are often replaced as a matter of course on a used engine.
11. Valvetronic motor and eccentric shaft sensor. The Valvetronic motor and its sensor cause limp-mode faults when they fail. Inspect the connector and the seal around the motor for oil.
12. Injectors and high-pressure fuel pump. Direct-injection engines rely on high-pressure pumps and precise injectors. Ask whether the injectors are original or updated and whether there were fuel pressure faults.

BMW 118i replacement engine cost

Our 118i engine stock runs to 137 units, priced from 1.275,00 € to 3.055,00 € with a median of 1.710,00 €.

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.

118i engine prices by model year

Engines from 2010–2014 have a median of 1.703,00 €, while units from 2020–2024 sit at 1.767,00 €. Newer engines usually cost more because they come from younger donor cars with lower mileage and later updates.

118i engine prices by mileage

Mileage matters less than history on a well-maintained BMW engine, but it is a useful guide. A low-mileage unit from a younger car gives you more life for a modest premium.

35 of these come from F40 donor cars, priced from 1.281,00 € to 3.055,00 €. An engine from the same body is the most direct swap because the sump, mounts and ancillaries already match.

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.

Replacement engines in stock for the 118i

These 118i units are in our Hamburg yard right now. Each listing shows real photographs of the engine you receive, its mileage and what is fitted.

BMW F40 118i B38A15 Engine 2020, 53,800 km1.785,00 €BMW F40 118i B38A15 Engine 2019, 124,600 km1.853,00 €BMW F40 118i B38A15 Engine 2019, 203,000 km1.295,00 €BMW F40 118i B38A15 Engine 2020, 187,400 km1.519,00 €BMW F40 118i B38A15 Engine 2018, 207,900 km1.937,00 €BMW F40 118i B38A15 Engine 2016, 42,000 km1.773,00 €BMW F40 118i B38A15 Engine 2016, 161,000 km1.430,00 €BMW F40 118i B38A15 Engine 2016, 71,400 km1.457,00 €BMW F40 118i B38B15 Engine 20201.805,00 €BMW F40 118i B38A15 Engine 2022, 99,700 km1.798,00 €BMW F40 118i B38A15 Engine 2018, 69,300 km1.440,00 €BMW F40 118i B38A15 Engine 2020, 118,200 km1.423,00 €

BMW F40 118i B38A15 Engine 2020, 53,800 km — 1.785,00 €, reduced from 3.000,00 €. It comes from a 2020 donor car with 53,800 km, and 22 units are available. We can confirm fitment against your VIN the same day.

BMW F40 118i B38A15 Engine 2019, 124,600 km — 1.853,00 €, reduced from 2.650,00 €. It comes from a 2019 donor car with 124,600 km, and 15 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW F40 118i B38A15 Engine 2019, 203,000 km — 1.295,00 €, reduced from 2.150,00 €. It comes from a 2019 donor car with 203,000 km, and 6 units are available. We can confirm fitment against your VIN the same day.

BMW F40 118i B38A15 Engine 2020, 187,400 km — 1.519,00 €, reduced from 2.400,00 €. It comes from a 2020 donor car with 187,400 km, and 27 units are available. We can confirm fitment against your VIN the same day.

BMW F40 118i B38A15 Engine 2018, 207,900 km — 1.937,00 €, reduced from 2.700,00 €. It comes from a 2018 donor car with 207,900 km, and 28 units are available. The listing shows every side of the engine and the fitted parts.

BMW F40 118i B38A15 Engine 2016, 42,000 km — 1.773,00 €, reduced from 2.950,00 €. It comes from a 2016 donor car with 42,000 km, and 29 units are available. The listing shows every side of the engine and the fitted parts.

BMW F40 118i B38A15 Engine 2016, 161,000 km — 1.430,00 €, reduced from 2.750,00 €. It comes from a 2016 donor car with 161,000 km, and 7 units are available. The listing shows every side of the engine and the fitted parts.

BMW F40 118i B38A15 Engine 2016, 71,400 km — 1.457,00 €, reduced from 2.350,00 €. It comes from a 2016 donor car with 71,400 km, and 13 units are available. The listing shows every side of the engine and the fitted parts.

BMW F40 118i B38B15 Engine 2020 — 1.805,00 €, reduced from 2.250,00 €. It comes from a 2020 donor car, and 19 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW F40 118i B38A15 Engine 2022, 99,700 km — 1.798,00 €, reduced from 3.000,00 €. It comes from a 2022 donor car with 99,700 km, and 12 units are available. We can confirm fitment against your VIN the same day.

BMW F40 118i B38A15 Engine 2018, 69,300 km — 1.440,00 €, reduced from 2.600,00 €. It comes from a 2018 donor car with 69,300 km, and 28 units are available. We can confirm fitment against your VIN the same day.

BMW F40 118i B38A15 Engine 2020, 118,200 km — 1.423,00 €, reduced from 2.350,00 €. It comes from a 2020 donor car with 118,200 km, and 23 units are available. The listing shows every side of the engine and the fitted parts.

Will it fit my 118i?

Will the B38B15 fit my BMW F40 118i?

The B38B15 is the original engine for the BMW F40 118i, which makes it the straightforward choice. The third 1 Series was built 2019–, and the B38B15 was produced 2014–2026, so check that your car's build date falls inside that window. Confirm the drive type (front-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 F40 118i?

We have 2 B38B15 engines from F40 donor cars, priced from 1.805,00 € to 3.055,00 €. Delivery to your door is included, and the engine carries a 12-month warranty when fitted by a qualified workshop. Add fitting labour and the parts you replace at the same time — seals, cooling parts and mounts — to estimate the total.

Fitting a replacement engine in the 118i

1. 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.
2. Replace the rear timing chain if in doubt. On engines with the chain at the gearbox end, chain work needs the engine out. If the history is unknown, replace the chain, guides and tensioner before fitting.
3. Prepare the turbo. Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting.
4. Reset VANOS adaptations. Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
5. Teach the Valvetronic limit stops. Run the Valvetronic learning routine so the ECU knows the eccentric shaft limits.
6. 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.
7. 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.
8. 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.
9. 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.

Delivery, warranty and payment

Every 118i 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 F40 engines · B38 engine guide · BMW 118i engines for sale · Send us your VIN