BMW X6 M (F86) engine: which one, problems and replacement

The BMW X6 M in the X6 M generation (F86, built 2014–2019) was built with one engine, the S63B44: a 4.4 L petrol V8 with 560 hp.

This guide tells you which engine your X6 M has, what goes wrong with it, what a replacement costs from our stock and what else to plan for when you fit one.

• Generation: X6 M, 2014–2019
• Body styles: F86 (SAC)
• Engines: S63B44
• Output: 560 hp
• Replacement engines in stock: 134 from 8.668,00 €

Which engine is in your X6 M?

S63B44 in the X6 M

The S63B44 was used in the F86 X6 M, built 2010–2017. It is a 4.4 L twin-turbo petrol V8 with 560 hp and 680 Nm.

Reading the code: S marks an S-series code, reserved for engines developed by BMW M; 63 is the family number; B stands for petrol (from the German Benzin); 44 is the capacity in decilitres, so 4.4 litres.

X6 M engines by model year

The X6 M kept the same engine for the whole F86 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 X6 M

A replacement engine does not have to come from another X6 M. 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.

S63B44: BMW F10 M5, BMW F06 M6, BMW F85 X5 M.

How to confirm your engine code

The X6 M only used the S63B44, 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 X6 M engine problems

The S63B44 in the X6 M shares the known weak points of the S63 family. Full S63 guide.

Rod bearings. Early S63 engines can show rod bearing wear, especially with long oil intervals.

Injectors. Injectors fail and cause misfires.

Turbochargers. Turbos wear and leak oil because of heat inside the V.

Valve stem seals. Seals harden and cause oil consumption.

Timing chain. Chains stretch at high mileage.

Symptoms to watch for on the X6 M

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.

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.

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.

Oil pressure warning or bearing noise at high revs. On M engines, a warning at high revs can be the first sign of bearing wear. Check the oil level and stop driving hard until it is diagnosed.

Looking after the X6 M engine

• Oil: 0W-30 or 5W-30 BMW Longlife-01, about 9 litres.
• Service interval: Oil every 7,500 to 10,000 km; shorter if driven hard.
• Timing drive: Timing chains, one per bank.
• Workshop notes: Prefer later S63TU and T4 engines. Check the version code before ordering.

Buying a used engine for the X6 M: checklist

1. 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.
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. 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.
4. 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.
5. 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.
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. 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.
9. 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.
10. 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.
11. Bearing and valve clearance history. M engines are built to tighter tolerances. Ask for the last rod bearing replacement and valve clearance check, and consider an oil analysis if the engine can be run.
12. Both cylinder banks. On a V engine, check compression, plugs and coils on both banks. Faults on one bank alone are common and easy to miss on a quick test.

BMW X6 M replacement engine cost

We currently hold 134 X6 M engine engines. The cheapest is 8.668,00 €, the most expensive 15.656,00 €, and half of them cost less than 13.338,00 €.

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.

X6 M engine prices by model year

Engines from 2015–2019 have a median of 12.987,00 €, while units from 2025–2029 sit at 11.813,00 €. Newer engines usually cost more because they come from younger donor cars with lower mileage and later updates.

X6 M 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.

1 of these come from F86 donor cars, priced from 15.550,00 €. 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 X6 M

Here is a selection of X6 M engines currently on our shelves, photographed in the yard. Click any of them for the full photographs, mileage and specification.

BMW F91 M8 S63B44 Engine 2022, 59,500 km15.044,00 €BMW F90 M5 S63B44 Engine 2018, 31,600 km14.915,00 €BMW F90 M5 S63B44 Engine 2018, 102,300 km14.766,00 €BMW F90 M5 S63B44 Engine 2020, 67,900 km13.678,00 €BMW F90 M5 S63B44 Engine 2017, 146,300 km14.486,00 €BMW F90 M5 Competition S63B44 Engine 2020, 174,500 km12.138,00 €BMW F90 M5 S63B44 Engine 2017, 149,300 km10.604,00 €BMW F90 M5 Competition S63B44 Engine 2024, 139,600 km11.127,00 €BMW F95 X5 M S63B44 Engine 2020, 63,800 km10.633,00 €BMW F91 M8 S63B44 Engine 2021, 91,200 km15.255,00 €BMW F95 X5 M S63B44 Engine 2018, 113,200 km11.975,00 €BMW F95 X5 M S63B44 Engine 2018, 97,100 km15.163,00 €

BMW F91 M8 S63B44 Engine 2022, 59,500 km — 15.044,00 €, reduced from 16.250,00 €. It comes from a 2022 donor car with 59,500 km, and 28 units are available. We can confirm fitment against your VIN the same day.

BMW F90 M5 S63B44 Engine 2018, 31,600 km — 14.915,00 €, reduced from 15.600,00 €. It comes from a 2018 donor car with 31,600 km, and 12 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW F90 M5 S63B44 Engine 2018, 102,300 km — 14.766,00 €, reduced from 16.250,00 €. It comes from a 2018 donor car with 102,300 km, and 10 units are available. The listing shows every side of the engine and the fitted parts.

BMW F90 M5 S63B44 Engine 2020, 67,900 km — 13.678,00 €, reduced from 14.450,00 €. It comes from a 2020 donor car with 67,900 km, and 30 units are available. The listing shows every side of the engine and the fitted parts.

BMW F90 M5 S63B44 Engine 2017, 146,300 km — 14.486,00 €, reduced from 15.650,00 €. It comes from a 2017 donor car with 146,300 km, and 14 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW F90 M5 Competition S63B44 Engine 2020, 174,500 km — 12.138,00 €, reduced from 13.350,00 €. It comes from a 2020 donor car with 174,500 km, and 6 units are available. We can confirm fitment against your VIN the same day.

BMW F90 M5 S63B44 Engine 2017, 149,300 km — 10.604,00 €, reduced from 11.400,00 €. It comes from a 2017 donor car with 149,300 km, and 22 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW F90 M5 Competition S63B44 Engine 2024, 139,600 km — 11.127,00 €, reduced from 12.600,00 €. It comes from a 2024 donor car with 139,600 km, and 25 units are available. The listing shows every side of the engine and the fitted parts.

BMW F95 X5 M S63B44 Engine 2020, 63,800 km — 10.633,00 €, reduced from 11.550,00 €. It comes from a 2020 donor car with 63,800 km, and 28 units are available. The listing shows every side of the engine and the fitted parts.

BMW F91 M8 S63B44 Engine 2021, 91,200 km — 15.255,00 €, reduced from 16.100,00 €. It comes from a 2021 donor car with 91,200 km, and 16 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW F95 X5 M S63B44 Engine 2018, 113,200 km — 11.975,00 €, reduced from 12.750,00 €. It comes from a 2018 donor car with 113,200 km, and 21 units are available. Ask the desk for compression figures or extra photographs before you order.

BMW F95 X5 M S63B44 Engine 2018, 97,100 km — 15.163,00 €, reduced from 16.250,00 €. It comes from a 2018 donor car with 97,100 km, and 5 units are available. Ask the desk for compression figures or extra photographs before you order.

Will it fit my X6 M?

Will the S63B44 fit my BMW F86 X6 M?

Yes, the BMW F86 X6 M left the factory with the S63B44, so an S63B44 from another car is the direct replacement. The X6 M was built 2014–2019, and the S63B44 was produced 2010–2017, so check that your car's build date falls inside that window. Confirm the drive type (rear-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 F86 X6 M?

We have 1 S63B44 engine from F86 donor cars, priced from 15.550,00 €. 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 X6 M

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. 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.
3. Reset VANOS adaptations. Clear the VANOS adaptations so the ECU learns the camshaft positions of the new engine.
4. 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.
5. 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.
6. 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.
7. 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

Before an X6 M engine 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.

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.

S63 engine guide · Send us your VIN