BMW X1 18i (F48) engine: which one, problems and replacement

The BMW X1 18i in the second X1 generation (F48, built 2015–2022) was built with one engine, the B38B15A: a 1.5 L petrol inline-3 with 140 hp.

Below you will find how to identify the engine in your X1 18i, the faults to look for, current prices for a replacement and the swap options that make sense.

• Generation: second X1, 2015–2022
• Body styles: F48 (SAV)
• Engines: B38B15A
• Output: 140 hp
• Replacement engines in stock: 18 from 901,00 €

Which engine is in your X1 18i?

B38B15A in the X1 18i

The B38B15A was used in the F48 X1 18i, built 2015–2024. It is a 1.5 L turbocharged petrol inline-3 with 140 hp and 220 Nm.

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; A identifies the version or output stage.

X1 18i engines by model year

The X1 18i kept the same engine for the whole F48 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 X1 18i

A replacement engine does not have to come from another X1 18i. 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.

B38B15A: BMW F39 X2 18i.

How to confirm your engine code

The X1 18i only used the B38B15A, 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 X1 18i engine problems

The B38B15A in the X1 18i shares 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 X1 18i

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 X1 18i 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 X1 18i: checklist

1. 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.
2. 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.
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. 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.
5. 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.
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 X1 18i replacement engine cost

Across 18 X1 18i engine units in our stock today, prices start at 901,00 € and reach 4.236,00 €. The median — the price in the middle of the range — is 2.250,00 €.

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.

X1 18i engine prices by model year

Engines from 2005–2009 have a median of 2.105,00 €, while units from 2020–2024 sit at 3.144,00 €. Newer engines usually cost more because they come from younger donor cars with lower mileage and later updates.

X1 18i 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.

2 of these come from F48 donor cars, priced from 1.343,00 € to 2.707,00 €. 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 X1 18i

These X1 18i 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 B38B15A Engine 218i F22 20132.890,00 €Used BMW X1 18i 2018 B38B15A F48 Engine2.707,00 €BMW 118i F20 B38B15A Engine 2015 · 82,000 km1.525,00 €B38B15A Complete Engine BMW 118i F202.344,00 €BMW F39 X2 18i B38B15A Complete Engine1.352,00 €BMW B38B15A Engine1.400,00 €

BMW B38B15A Engine 218i F22 2013 — 2.890,00 €, reduced from 3.650,00 €. It comes from a 2013 donor car, and 27 units are available. Ask the desk for compression figures or extra photographs before you order.

Used BMW X1 18i 2018 B38B15A F48 Engine — 2.707,00 €, reduced from 3.600,00 €. It comes from a 2018 donor car, and 19 units are available. We can confirm fitment against your VIN the same day.

BMW 118i F20 B38B15A Engine 2015 · 82,000 km — 1.525,00 €, reduced from 2.250,00 €. It comes from a 2015 donor car with 82,000 km, and 7 units are available. We can confirm fitment against your VIN the same day.

B38B15A Complete Engine BMW 118i F20 — 2.344,00 €, reduced from 2.700,00 €. It comes from a recorded donor car, and 30 units are available. We can confirm fitment against your VIN the same day.

BMW F39 X2 18i B38B15A Complete Engine — 1.352,00 €, reduced from 1.850,00 €. It comes from a recorded donor car, and 16 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW B38B15A Engine — 1.400,00 €, reduced from 1.850,00 €. It comes from a recorded donor car, and 26 units are available. The listing shows every side of the engine and the fitted parts.

Will it fit my X1 18i?

Will the B38B15A fit my BMW F48 X1 18i?

For the BMW F48 X1 18i, the B38B15A is the factory engine and the one to order. The second X1 was built 2015–2022, and the B38B15A was produced 2015–2024, 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 F48 X1 18i?

We have 2 B38B15A engines from F48 donor cars, priced from 1.343,00 € to 2.707,00 €. 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.

Engine swaps and upgrades for the X1 18i

These engines were fitted to other versions of the F48 at the factory, which makes them the most practical upgrades: the body was designed around them and many parts are shared.

Can I fit the B47C20 in my X1 18i?

It is a full conversion: the B47C20 runs on diesel and the B38B15A on petrol, so the fuel system, wiring, engine control unit, instrument coding and usually the gearbox change too. The gain is 50 hp and 180 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Can I fit the B48A20 in my X1 18i?

It is a conversion rather than a replacement: the B48A20 is an inline-4 and your B38B15A an inline-3, so mounts, sump, cooling, exhaust, wiring and the engine control unit all change. The gain is 52 hp and 60 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Fitting a replacement engine in the X1 18i

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 X1 18i 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.

A 12-month warranty covers eligible internal failure when the engine is fitted by a qualified workshop with new fluids and filters. You can pay by card, bank transfer or crypto and receive the invoice by email straight away.

All F48 engines · B38 engine guide · BMW X1 18i engines for sale · Send us your VIN