Bulletin
Engine code

IA Technical Bulletin

BMW S63 Engine Guide

Engine: S63

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S63 (S63B44O0, S63B44T0, S63B44T2, S63B44T4) · 4,395 cc twin-turbo V8 with cross-bank exhaust · US-market builds from 07/2009 · X5 M, X6 M, M5, M6, M8

The S63 is BMW M's 4.4 liter twin-turbo V8. It first appears in the E70 X5 M and E71 X6 M. BMW's training material calls the S63TU a further development of that engine, and the successor to the S85 V10 in the M5 and M6. IAIK describes the 4,395 cc S63 V8 family as a hot-V layout with cross-bank exhaust routing feeding twin-scroll turbochargers.

This guide keeps the generations apart, because the sources do. IAIK separates the original S63, the S63TU (F10 M5 era) and the S63TU4 (F90 M5 era), and says they need distinct specifications. BMW Technical Training, S63TU4 Engine (ST1916, p.6-7 and p.9), lists a further engine, the S63B44T2, for the F85 X5 M and F86 X6 M, and calls it the S63TU2. IAIK does not name it. The same manual gives the S63B44T4 lineage as the S63B44T2 first, with the N63TU3 (N63B44T3) as its technical base (p.6), and notes that no engine is coded S63B44T3 (p.10). Where a statement applies to one generation, the text says which.

For the S63TU, BMW's training says the aim was better response and rev character with lower fuel use, not more power than the original S63. It lists a new cylinder head, third-generation Valvetronic, new VANOS, a two-stage oil pump and twin-scroll turbochargers with a cross-bank exhaust manifold among the changes. IAIK places Valvetronic's arrival in this engine branch with the S63TU.

Quick read

Ownership position: IAIK's position is to confirm the exact M-engine variant before planning oil-system or turbocharger work.
Reliability: Not established as a rating for the whole family. IAIK, from our own shop: the S63TU4 Competition is among the three most solid engines it sees. BMW's recalls and service actions for these engines are listed by generation under Known Failure Points and Service Items.
Cost to own: Not established by IAIK. No figures are given here.
Power potential: Not established by IAIK. BMW's factory figures in the sources read run from 555 hp (original S63) to 600 hp (S63TU4 in the F90 M5). BMW's S63TU4 training also lists a 617 hp Competition version of the F90 M5, in US units.
Main watch item: Do not treat every reduced-power complaint as a failed turbocharger. IAIK asks for exhaust sealing, wastegate vacuum control and oil supply to be assessed separately.

Where you find it

These lists use US-market build dates from BMW's parts catalog data, which ends in December 2019. They are build dates, not model years. Check the VIN before you rely on a range.

Original S63 (S63B44O0): X5 M (E70), built 07/2009 to 06/2013. X6 M (E71), built 07/2009 to 06/2014.
S63TU (S63B44T0): M5 (F10), built 03/2012 to 10/2016. M6 Gran Coupe (F06), built 03/2013 to 09/2018. M6 Convertible (F12), built 03/2012 to 05/2018. M6 Coupe (F13), built 07/2012 to 08/2017. The later dates in each range are facelift cars.
S63TU2 (S63B44T2): X5 M (F85), built 12/2014 to 06/2018. X6 M (F86), built 12/2014 to 05/2019.
S63TU4 (S63B44T4): M5 (F90), built from 11/2017. M8 Convertible (F91) and M8 Coupe (F92), built from 07/2019. M8 Gran Coupe (F93), built from 11/2019. The catalog data ends in 12/2019, so later builds are not covered here.

BMW's S63TU training gives series introduction as June 2012 for the F12 M6 Convertible, and August 2012 for the F10 M5 Sedan and F13 M6 Coupe. Wikipedia lists later F95 X5 M and F96 X6 M cars with the S63B44T4. The other sources read here do not cover those cars.

BMW's S63TU4 training (ST1916, p.6) gives first use of the S63B44T4 as 11/2017 in the M5 and 07/2019 in the M8, the same starts as the build dates above. Its engine history table (p.9) gives first use by year only: E70 and E71 in 2010, F10 M5 in 2011, F12 and F13 M6 in 2012, F06 M6 in 2013, F85 and F86 in 2015, F90 M5 in 2017. It does not say which market it means or what kind of year it is. Two of the years do not line up with dates above: 2011 for the F10 M5 sits against the August 2012 series introduction in the S63TU training, and 2010 for the E70 and E71 sits beside the 07/2009 build start in the parts data and the 3/2009 start in BMW's valve seal bulletin. None of this is resolved here.

BMW's S63TU4 training ties the S63B44T2 to the F85 X5 M and F86 X6 M by series and model name (ST1916, p.6-7 and p.9). BMW's press release and engine description give the same 575 hp and 750 Nm figures, and BMW's oil chart calls their engine S63R.

S63 At a Glance

Question	Practical answer
Factory output	Original S63: 555 hp and 680 Nm. S63TU: 560 hp and 680 Nm. S63B44T2: 575 hp and 750 Nm. S63TU4 in the F90 M5: 600 hp and 750 Nm. IAIK lists no output figures. BMW's S63TU4 training prints US-unit figures for the same engines, for example 567 hp and 553 ft lb for the S63B44T2, shown under Technical Specifications.
Reliability profile	Not established by IAIK. BMW documents show recalls and service actions by generation, listed below. They are not failure rates.
Best ownership indicator	IAIK points to a correctly identified variant and a kept record of oil consumption, smoke behavior and repair history.
Typical annual planning budget	Not established by IAIK.
Possible first-year catch-up	Not established by IAIK.
Largest common repair exposure	Not established by IAIK.
Common tuned street range	Not established by IAIK.
Upgraded-turbo range	Not established by IAIK.
Engine oil	BMW's February 2017 oil chart lists 0W-30 LL01FE. Fill quantities differ by generation and are in the specification table.
Before buying or modifying	Identify the exact variant. Check smoke behavior, oil consumption and repair records. Ask a BMW dealer whether any recall or service action is open on the VIN. IAIK warns that competition output figures and hardware from another M generation do not prove a parts combination is compatible.

Technical Specifications

Each row says which generation it covers. Where a figure is missing for a generation, the sources read do not give it.

Specification	Detail
Configuration	V8. IAIK describes a hot-V layout with cross-bank exhaust routing feeding twin-scroll turbochargers for the family. BMW's training confirms two twin-scroll turbochargers and a cross-bank manifold for the S63TU. BMW's S63TU4 training says the S63B44T2 and S63B44T4 also have two twin-scroll turbochargers on cross-bank 4-in-2 manifolds (ST1916, p.34).
Engine codes	Original S63: S63B44O0. S63TU: S63B44T0. S63TU2: S63B44T2, for the F85 and F86. S63TU4: S63B44T4. BMW's S63TU4 training notes that no engine is coded S63B44T3 (ST1916, p.10).
Displacement, bore, stroke	4,395 cc for the family. Original S63 and S63TU: 89 mm bore, 88.3 mm stroke. BMW's S63TU4 training gives 4,395 cc and 89 mm by 88.3 mm for the S63B44T0, S63B44T2 and S63B44T4 (ST1916, p.7). S63B44T2 uses the S63TU crankshaft drive.
Compression ratio	Original S63: 9.3:1. S63TU: 10.0:1. S63B44T2 and S63TU4: 10.0:1 (ST1916, p.7).
Power	Original S63: 555 hp at 6,000 rpm. S63TU: 560 hp at 6,000-7,000 rpm. S63B44T2: 575 hp (423 kW) at 6,000-6,500 rpm. S63TU4 in the F90 M5: 600 hp (441 kW) at 5,600-6,700 rpm.
Torque	Original S63: 680 Nm (500 lb-ft) at 1,500-5,650 rpm. S63TU: 680 Nm (500 lb-ft) at 1,500-5,750 rpm. S63B44T2: 750 Nm (553 lb-ft) at 2,200-5,000 rpm. S63TU4 in the F90 M5: 750 Nm (553 lb-ft) at 1,800-5,600 rpm. BMW's S63TU4 training prints a different figure for the original S63, 442 ft lb (see the engine history table below).
Power and torque, US units	BMW's S63TU4 training prints US units (ST1916, p.7). S63B44T0: 553 hp, or 567 hp with the Competition package, at 6,000-7,000 rpm; 501 ft lb at 1,500-5,750 rpm, or at 1,500-6,000 rpm with the Competition package. S63B44T2: 567 hp at 6,000-6,500 rpm; 553 ft lb at 2,200-5,000 rpm. S63B44T4: 591 hp, or 617 hp with the Competition package, at 6,000 rpm as printed; 553 ft lb at 1,800-5,600 rpm, or at 1,800-5,860 rpm with the Competition package. The gap to the figures above is a unit difference: 423 kW is 575 metric hp or about 567 US hp, and 441 kW is 600 metric hp or about 591 US hp. The older figures line up the same way, with 547 US hp (p.9) about 555 metric hp and 553 US hp about 560.
Rev limit	Original S63: 6,800 rpm. S63TU: 7,200 rpm. S63B44T2: 6,800 rpm. S63TU4: 7,200 rpm (ST1916, p.7).
Firing order	1-5-4-8-6-3-7-2 for the original S63 and S63TU. BMW's S63TU4 training prints the same order for the S63B44T0, S63B44T2 and S63B44T4 (ST1916, p.7).
Valvetrain	Four valves per cylinder. Original S63: double VANOS, 50 degrees intake and 50 degrees exhaust adjustment. S63TU: Valvetronic and double VANOS, 70 degrees intake and 55 degrees exhaust adjustment. S63TU4: Valvetronic III, with the servomotor on the intake side of the cylinder head, and the VANOS solenoid valves sitting in the head cover (ST1916, p.15). S63B44T2: not stated in BMW's technical documents read, though BMW's 2014 press release lists Valvetronic among the technologies of the F85 and F86 engine.
Crankcase	S63TU4: BMW's S63TU4 training says the closed-deck crankcase comes from the N63B44O2, adapted, with lateral bolts added to the main bearing cap bolting for the higher output (ST1916, p.11-12). From 07/2019 the cylinder bores are electric arc wire sprayed, as in BMW's modular engines (p.11).
Rotating assembly	S63TU: forged steel crankshaft on five bearings with lead-free bearing shells, cracked forged connecting rods, cast pistons. S63B44T2 takes its crankshaft drive from the S63TU. S63TU4: BMW's S63TU4 training says the crankshaft drive, less pistons and bearing shells, matches the S63B44T2's (ST1916, p.12). From 07/2019 it has a new main bearing shell material and new cast pistons, graphite-coated on the skirt (p.12).
Fuel system	S63TU: direct injection with solenoid injectors rated to 200 bar and one high-pressure pump per bank. S63TU4: two high-pressure pumps. BMW's S63TU4 training gives injection pressure up to 350 bar, with Bosch HDEV 6 solenoid injectors, for the S63B44T4 (ST1916, p.42). Fuel: 95-98 RON for the original S63 and S63TU. The same training lists usable fuel as 95-98 RON (91-93 AKI) for the S63B44T0 and S63B44T2 and 91-98 RON (87-93 AKI) for the S63B44T4, and gives 98 RON (93 AKI) as the fuel rating for all three (p.7).
Engine management	Original S63: MSD85.1. S63TU: MEVD17.2.8, two control units, one per bank, mounted on the engine and coolant-cooled. S63B44T2: MEVD17.2.H (ST1916, p.7). S63TU4: DME 8.8.T, a Bosch eighth-generation unit, again with one control unit per bank fixed to the engine (p.45). BMW's S63TU4 training prints the S63TU as MEVD17.2.H (p.7), where the S63TU training says MEVD17.2.8. Not resolved here.
Turbochargers	S63TU4: two twin-scroll units from Honeywell, the same part on both banks, with one-piece wastegate valves, electric wastegate actuators and no blow-off valve. BMW says the compressor and the wastegate actuation are the changes from the S63B44T2 (ST1916, p.34-35).
Charge-air coolers	S63TU4: about 160 °C (320 °F) in and under 50 °C (122 °F) out, 32 kW cooling power at 2.7 bar charging pressure, with the two banks' coolers joined by a connecting piece that equalizes pressure (ST1916, p.44).
Engine oil	0W-30 LL01FE per BMW's February 2017 oil chart. Fill quantities in that chart: E70 and E71 (S63) 9.0 quarts (8.5 liters). F06, F10, F12 and F13 M cars (S63T) 9.0 quarts (8.5 liters). F85 and F86 (S63R) 10.0 quarts (9.5 liters). F90 (S63M) 10.5 quarts (10.0 liters).
Oil fill conflict	BMW's workshop data for the F10 M5 lists 9.5 liters for an oil change with filter, which does not match the chart's 8.5 liters for the S63TU. This is not resolved here. Confirm the fill on the car.

BMW engine history table (S63TU4 training, US units)

BMW's S63TU4 training (ST1916, p.9) lists each application with a first-use year, output in hp and torque in ft lb. Every engine in it is 4,395 cc.

S63B44O0, E70 X5 M and E71 X6 M: first used 2010, 547 hp, 442 ft lb.
S63B44T0, F10 M5 first used 2011, F12 and F13 M6 in 2012, F06 M6 in 2013: each 553 hp and 501 ft lb.
S63B44T0 Competition, F12 and F13 M6 in 2012, F10 M5 in 2013, F06 M6 in 2013: each 567 hp and 501 ft lb.
S63B44T0, F10 M5 "30 Years M5" in 2014, F12 and F13 M6 Competition in 2015, F06 M6 Competition in 2015: each 591 hp and 516 ft lb.
S63B44T2, F85 X5 M and F86 X6 M: first used 2015, 567 hp, 553 ft lb.
S63B44T4, F90 M5: first used 2017, 591 hp, 553 ft lb. F90 M5 Competition: 2018, 617 hp, 553 ft lb.

The 442 ft lb given for the original S63 does not match the 680 Nm (500 lb-ft) in the S63TU training. This is not resolved here.

The Insider Read

IAIK's first instruction for this engine is to confirm the exact M-engine variant before planning oil-system or turbocharger work. The S63, S63TU and S63TU4 share a displacement and a general layout, but IAIK says they need distinct specifications, and that the earlier and later engines should not inherit every TU assembly instruction.

IAIK treats a reduced-power complaint as a diagnosis problem, not a parts order. Exhaust sealing, wastegate vacuum control and oil supply are separate questions. A damaged line or connection is not the same fault as a turbocharger or manifold fault.

IAIK also warns against reading competition output figures, or hardware from another M generation, as proof that a parts combination is compatible. Before a rebuild it asks for the exact engine, turbocharger assembly, oil-pump arrangement and parts supersessions to be recorded. It says clearances, bearing selection, fastener procedures and first oil-system commissioning need the matching repair information.

IAIK gives no ownership cost and no output figures for this engine, and its shop view, below, covers the S63TU4 Competition only.

What IAIK sees in our shop

The notes in this part come from IAIK's own shop experience, not from BMW figures, and they are not failure rates.

IAIK's praise is for the S63TU4 in Competition form, which IAIK ranks among the three most solid engines it sees in our shop. IAIK has never seen an engine issue on one.

In our shop, IAIK sees these cars come in mostly for recall work.

Apart from that, the items IAIK sees are driveshaft flex disc (guibo) wear and rear differential leaks, with front differential leaks rarely, and IAIK sees those across all-wheel-drive (xDrive) BMWs in general, not as an engine item.

Factory Deep Dive

Cross-bank exhaust pulse routing

IAIK describes cross-bank exhaust routing that feeds twin-scroll turbochargers. Routing exhaust from cylinders on opposing banks lets the turbine feeds be organized around firing pulses, rather than treating each bank as an isolated four-cylinder engine. IAIK says the point is pulse separation and turbine response, not a promise of zero lag or zero exhaust interference.

For the S63TU, BMW's training describes a four-into-two cross-bank manifold. One turbocharger receives cylinder pairs 1 and 6 and pairs 4 and 7. The other receives pairs 2 and 8 and pairs 3 and 5. The training says this leaves 360 degrees of crankshaft angle between exhaust pulses in each turbine feed. It also says the S63TU manifold replaces the earlier S63 double-wall manifold with an open-pipe design under ventilated heat shields, with corrugated elements to absorb thermal movement, and that there is one catalytic converter per bank.

BMW's training says the S63TU has no blow-off valve, and credits Valvetronic and special programming for that. BMW's S63TU4 training (ST1916, p.34-35) says the S63B44T4 has no blow-off valve either, uses the same twin-scroll turbocharger part on both banks, and has electrically actuated wastegates. That differs from the vacuum-actuated wastegates in the S63TU training. It adds that the S63B44T4 turbochargers, supplied by Honeywell, follow the S63B44T2 design apart from a new compressor and impeller and the wastegate actuation, and that their wastegate valves are one-piece.

Oil supply: two pump stages with different jobs

IAIK says the S63TU oil system addresses oil moving toward the front of the sump during heavy braking. A G-rotor intake stage transfers oil from the front area toward the rear. A volume-controlled pendulum slide-cell pressure stage draws from the rear area and supplies the lubrication circuit. The two stages share a housing but do different jobs. IAIK says this is not a reason to call the whole S63 family dry-sump, and that it does not establish one common pump or priming procedure across the S63, S63TU and S63TU4.

BMW's training agrees on the S63TU design. It says heavy braking in the M5 and M6 can push oil to the front of the pan, where the pendulum slide-cell pump alone could not guarantee supply, so the pump has an intake stage and a pressure stage in one housing, chain-driven from the crankshaft. The full-flow oil filter is bolted into the oil pan from below. An oil thermostat opens the cooler circuit from an oil temperature of 100 °C. The filter bypass opens at about 2.5 bar of pressure difference, raised from 2.0 bar to protect the lead-free bearings.

The variants differ.

S63B44T2: BMW's engine description says the oil pump comes from the N63B44O1, the intake snorkel was reshaped for track use, and supply is kept up to 1.2 g of longitudinal or lateral acceleration.
S63TU4 pump: BMW's S63TU4 training (ST1916, p.18-28) describes an external gear pump, chain-driven from the crankshaft, in place of the N63B44O2 pendulum slide-cell pump. Delivery is varied by sliding one gear sideways under oil pressure. The engine control unit works out the target pressure from the engine's operating state and temperature and drives a proportional map control valve to match. A second hydraulic control takes over delivery when the map control fails.
S63TU4 sump: the small front sump acts as a volume buffer, and a plastic deflector with an integrated seal separates it from the rear sump. A second external gear pump, which BMW calls the suction pump, is flanged onto the main pump and moves oil from the front sump back to the rear. BMW says supply holds up to 1.3 g of longitudinal acceleration and up to a constant 1.3 g laterally (ST1916, p.18 and p.29). The filter module is built into the upper part of the sump on the engine's left, and carries the oil pressure sensor and the map control valve (p.18).
S63TU4 piston cooling: each cylinder has an inner and an outer oil spray nozzle, each with a valve that opens only at a set oil pressure. BMW's table gives the inner nozzle as opening at 3.3-3.7 bar and closing at 3.0 bar, against 2.25-2.65 bar and 2.0 bar on the S63B44T2. It gives the outer nozzle as opening at 4.5 bar and closing at 4.2 bar, while its text says 4.4 bar (ST1916, p.30-32). During warm-up the control unit can keep oil pressure below 3.3 bar, too low to open the nozzles. With no oil jet on them, the piston crowns get hot sooner and collect less condensed fuel. BMW ties this to the EURO 6 particle limit (p.31).

Cooling

BMW's training says the S63TU has separate coolant circuits for the engine and for charge-air cooling. The two control units are cooled by the charge-air circuit. Besides the belt-driven pump there are four electric coolant pumps: one for cabin heating, one for the turbochargers, and two for charge-air and control-unit cooling. The turbocharger pump can run for up to 30 minutes after shutdown, and the fan for up to 11 minutes. The map thermostat starts to open at 105 °C and is fully open at 120 °C when it is not electrically controlled.

The training also says the charge-air and control-unit circuit has no coolant level switch, so a low level is not detected automatically. A warning lamp for high intake air temperature with reduced power, or for insufficient control-unit cooling, then shows in the cluster with a Check Control message.

BMW's engine description for the S63B44T2 says the control units are no longer coolant-cooled, and its two charge-air coolant pumps serve the radiator feed and return rather than one bank each.

BMW's S63TU4 training says the control unit coolant connections are not connected on the S63B44T2 and S63B44T4 (ST1916, p.46). For the S63B44T4 charge-air coolers it gives about 160 °C (320 °F) in and under 50 °C (122 °F) out at 2.7 bar charging pressure, 32 kW of cooling power, and a connecting piece that equalizes pressure between the two banks' coolers (p.44). It treats the rest of the engine cooling as vehicle-specific and does not describe it (p.44).

Valvetrain and rotating assembly

BMW's training says the S63TU adds fully variable valve lift (Valvetronic III) to double VANOS, and widens intake VANOS adjustment from 50 to 70 degrees. It says the S63TU exhaust valves are hollow and sodium-filled, and that for valvetrain service the engine is locked at 150 degrees before firing top dead center of cylinder 1 rather than at top dead center.

BMW's S63TU4 training says the S63B44T4 uses Valvetronic III, with the servomotor on the intake side of the cylinder head, and calls the mix of turbocharging, Valvetronic and direct injection TVDI (ST1916, p.15). The training does not say outright whether the S63B44T2 has Valvetronic. BMW's 2014 press release lists Valvetronic among the technologies of the F85 and F86 engine. This guide does not carry the S63TU valvetrain details over to either engine.

For the S63TU4, BMW's training (ST1916, p.11-15) says the crankcase comes from the N63B44O2, adapted, and the cylinder head follows the N63B44O2 concept, with the intake pipe partly built into the head and the VANOS solenoid valves moved into the head cover. It marks a running change at 07/2019: from then the bores are electric arc wire sprayed, the main bearing shells use a new material, and the pistons are new cast ones, graphite-coated on the skirt (p.11-12). The manual does not say what these parts were before 07/2019.

The same training gives the S63B44T4 a compression ratio of 10:1, against 10.5:1 on the N63B44T3, with the piston crown reshaped for 350 bar injectors (p.13). Each piston has eight skirt oil drains and an added groove below the scraper ring. BMW's stated aim is drainage: together they clear the oil the scraper ring pushes down, so it does not get past the rings, a point BMW stresses for overrun, when the combustion chambers are under vacuum (p.13).

Fuel system and crankcase ventilation

BMW's training says the S63TU uses solenoid injectors rated to 200 bar, one single-plunger high-pressure pump per bank driven from the exhaust camshaft, and welded high-pressure lines from rail to injector.

For the S63TU4, BMW's training (ST1916, p.42-43) says injection pressure rises from 200 to 350 bar, with Bosch HDEV 6 solenoid injectors and a reworked high-pressure pump piston and plunger. It says the injectors and the control unit work together under what BMW calls the CVO function, so a replacement injector or control unit must be selected by the car's VIN in BMW's parts catalog.

The S63TU crankcase ventilation is built into the cylinder head cover and works on the same principle as the N63. It uses a labyrinth oil separator and has no separate line to the intake. In naturally aspirated running the crankcase vacuum is limited to a maximum of 100 mbar. Under boost the cleaned blow-by gas is routed to the compressor side of the turbochargers.

For the S63TU4, BMW's training says each head cover carries its own labyrinth oil separator, as on the S63TU (ST1916, p.17). It says the US and European versions have no hot-film air mass meter: the control unit works out air mass from a stored model fed by VANOS position, throttle position, air and engine temperature, engine speed, manifold pressure difference and ambient pressure (p.39). A crankcase pressure sensor and a tank ventilation differential pressure sensor let the control units detect leaks in those systems, and a leak is reported as a Check Control message (p.39-41).

Technician service notes

S63TU turbocharger positioning is an assembly requirement. BMW's S63TU training requires the turbochargers to be positioned with alignment equipment during installation, and names a different special tool for locating the cross-bank exhaust manifold. IAIK treats alignment as part of the installation procedure, not something to pull into place with fasteners. IAIK also says a turbocharger alignment instruction is not automatically the same operation as aligning the manifold. Use the current repair instruction before ordering tools or starting assembly.

S63TU vacuum reservoir. The training places the wastegate vacuum reservoir on the lower side of the oil pan, not in the engine's V. IAIK says to identify the reservoir and vacuum lines before moving components when planning sump or subframe access, and to inspect the lines and connections when they are disturbed. IAIK adds that a damaged vacuum path can affect wastegate control, but a boost complaint still needs diagnosis, because the location alone does not establish the cause of a reduced-power event.

S63TU fuel system. The training says not to open the fuel system when coolant temperature is above 40 °C (104 °F), because residual pressure can cause injury. It also says fuel must be kept off the ignition coils: long contact degrades their silicone, which can lead to arcing and misfires, and BMW calls for replacing any coil that is badly soaked in fuel. BMW's S63TU4 training gives the same 40 °C limit and the same coil warning for the S63B44T4 (ST1916, p.42-43).

S63TU control units. The training warns against swapping in control units from other cars to test them, because of the immobilizer, and says the immobilizer adjustment that follows cannot be undone. The S63TU4 training says the same about its control units (ST1916, p.46).

S63TU4 wastegates. BMW's S63TU4 training calls for a teach-in with BMW's diagnostic system whenever the electric wastegate controller is fitted by itself, and for a readjustment any time its adjusting linkage has been undone. A complete replacement turbocharger comes with the linkage already set, so the readjustment is not needed there. BMW rules out a resistance test on the wastegate position sensor, because it is a linear Hall sensor (ST1916, p.36). As on the S63TU, the training treats accurate turbocharger alignment at installation as a requirement (p.34).

S63TU4 oil service. BMW's S63TU4 training says the plan, as of its July 2019 status, includes an oil change at 1,200 miles as a running-in check. The upper sump section has a small drain hole so the front sump empties into the rear one during an oil service (ST1916, p.32).

S63TU4 air filter. On this engine an air filter change means taking out the front-end struts, according to BMW's S63TU4 training. The strut domes are aluminum, and once the struts have been off several times their threads may need repairing with thread inserts (ST1916, p.38).

Known Failure Points and Service Items

Recall information on this page was checked against NHTSA on October 1, 2026. Recalls are added and closed over time, and whether a specific car is covered is a VIN check with BMW or NHTSA.

The dossier gives one failure point in IAIK's own words. The rest come from BMW recalls and service bulletins that name these engines. They show what BMW documented. They are not failure rates.

01 Reduced power: separate exhaust, boost control and oil supply

IAIK asks for exhaust sealing, wastegate vacuum control and oil supply to be assessed separately, so that a damaged line or connection is not mistaken for a turbocharger or manifold fault. After any oil-system disassembly, IAIK says to verify the exact commissioning requirements for the engine and the parts replaced, and not to substitute a generic priming method. The vacuum-reservoir point applies to the S63TU. On the S63TU4 the wastegate actuators are electric, and BMW's training says no vacuum unit, vacuum lines or vacuum reservoir are needed for them (ST1916, p.35). If the actuator fails or its position signal is lost, the wastegate is left open: the engine then makes no boost, but the car can still be driven at reduced power (p.36).

Watch for a reduced-power complaint with no confirmed cause, damaged or loose vacuum lines, exhaust leaks, any oil-system work done without the engine-specific commissioning steps, and, on the S63TU4, a wastegate controller replaced without the teach-in.

02 Smoke, oil consumption and valve stem seals

IAIK asks for smoke to be recorded by when it appears: at a cold start, after warm idling, during driving, or after the driver reapplies the accelerator. Keep that with the reported oil consumption and the repair history. IAIK says a short video of the operating conditions is more useful than a description of a little smoke, and that smoke alone does not identify a failed part. It says the possible causes include valve stem seals, turbocharger seals and crankcase ventilation, and that a compression comparison must be read under the engine's test procedure.

BMW's bulletin SI B11 08 15 (March 2016) covers valve stem seal replacement on the S63 in the E70 X5 M, built 3/2009 to 6/2013, and the E71 X6 M, built 3/2009 to 6/2014. It lists three signs: smoke from the tailpipe when starting or when accelerating and decelerating aggressively, excessive oil consumption, and spark plugs fouled with oil. BMW's later bulletin SI B11 01 17 (November 2017) covers the S63T. Its model list includes F06, F10, F12 and F13 M cars built from 7/2012, and the F85 X5 M and F86 X6 M built from 3/2014.

SI B11 01 17 says that when oil consumption is the only complaint, a full oil consumption test under SI B11 03 13 comes first. When smoke is reproducible on a hot engine, it says to do and document compression and leak-down tests, and to check the crankcase ventilation lines and the turbocharger intake and outlet tubes for excess oil, before replacing seals.

BMW's oil consumption bulletin SI B11 03 13 says turbocharged engines use more oil than naturally aspirated ones. It allows up to 1 quart per 750 miles for BMW engines other than Motorsport engines, and up to 2.5 quarts per 1,000 miles for Motorsport engines. BMW's oil chart lists the S63 among its Motorsport gasoline engines. The documents read do not say which allowance BMW applies to each S63 generation, so confirm that before judging a car's consumption.

Watch for smoke at start-up or on throttle changes, oil use that has changed, oil-fouled spark plugs, and oil collecting in the crankcase ventilation lines or turbocharger tubes.

03 Turbocharger coolant lines (S63TU: F10 M5, F06, F12 and F13 M6)

BMW issued two service actions on the coolant lines that run to the turbochargers. SI B11 17 14 (December 2014) covers F06, F10, F12 and F13 M5 and M6 cars built October 2011 to July 2014. BMW gives the cause as excess heat around the lines and the situation as a possible coolant leak at the turbochargers. The action is to check the lines, replace them if they leak, and fit insulator sleeves to all four lines.

SI B11 08 17 (April 2017) covers F06, F10, F12 and F13 M5 and M6 cars built from March 2, 2012 to February 20, 2017. BMW says the line material may not withstand prolonged turbocharger temperatures, and the correction is to replace the coolant lines.

Watch for coolant loss, coolant leaking near the turbochargers, and a service action shown as open on the VIN.

04 Oil pump drive shaft recall 12V-475 (2013 M5 and M6)

BMW recalled 696 model year 2013 M5, M6 Coupe and M6 Convertible cars built July 19, 2012 through September 11, 2012. BMW says a manufacturing error left the tolerance between the oil pump drive shaft and the pump rotor out of specification, so the drive shaft could separate from the rotor. BMW says that could cause a sudden loss of oil pressure and severe engine damage, with a low oil pressure warning shown in the cluster. The remedy was to replace the oil pump.

Watch for a low oil pressure warning. Ask a BMW dealer to check the VIN, because this recall covers a narrow build window.

05 Electric auxiliary water pump recall 18V-248 (2011-2012 X5 M and X6 M)

BMW's recall 18V-248 lists model year 2011-2012 X5 M and X6 M cars built August 1, 2010 through December 31, 2011, among other models. BMW says the pump's electronic circuit board can malfunction and overheat, and that in an extreme case the pump can smolder and an engine compartment or vehicle fire cannot be excluded. The pump conducts heat away from the turbocharger after the engine is switched off. The remedy was to replace the pump.

These are original S63 cars. BMW's report names no warning sign a driver would see, so the practical step is to have a BMW dealer check the VIN.

06 Oil leak at the rear of the engine (SI B11 09 16)

BMW's bulletin SI B11 09 16 (February 2018) covers engine oil leaking from the center of the vehicle, seen between the engine and the transmission bell housing. It names the S63 and S63TU among the engines, and its model list includes the E70 X5 M, E71 X6 M, F10 M5, F12 M6 and F13 M6. BMW's parts list is an updated rear end cover kit and a cap with the rear crankshaft seal, used when diagnosis supports removing the transmission.

Watch for oil residue between the engine and the bell housing, and oil dripping from the middle of the car.

07 S63TU4 in the F90 M5: recalls 18V-323 and 19V-513

Recall 18V-323 covers model year 2018 F90 M5 cars built up to April 17, 2018, about 846 vehicles. BMW says a software error in the engine control unit can let fuel pressure drop, causing power loss and possible stalling, with the engine warning lamp and a drivetrain message. The remedy is a software update.

Recall 19V-513 covers F90 M5 cars, among other models, built October 10, 2018 to June 24, 2019. NHTSA lists the M5 under model year 2019. BMW says one or more high-pressure fuel pump mounting screws may have been tightened wrongly at assembly, and a loose screw can let vibration loosen the fuel line and eventually leak. The remedy replaces both high-pressure pumps and their screws.

IAIK sees S63TU4 cars come into our shop mostly for recall work.

Watch for power loss or stalling with a warning lamp, and for any fuel leak near the engine. Ask a BMW dealer to check the VIN for both recalls.

08 Charge-air and control-unit coolant level (S63TU)

The S63TU charge-air and control-unit cooling circuit has no coolant level switch, according to BMW's training, so a low level is not detected automatically. Low coolant shows up as a warning lamp for high intake air temperature with reduced power, or for insufficient control-unit cooling. This is an S63TU item: BMW's S63TU4 training says the control unit coolant connections are not connected on the S63B44T2 and S63B44T4 (ST1916, p.46).

Watch for a reduced-power event with an intake air temperature warning, and, because the circuit has no level switch, check its level during service.

09 Driveshaft flex disc and differential leaks (IAIK, all-wheel-drive cars)

IAIK sees driveshaft flex disc (guibo) wear and rear differential leaks on these cars in our shop, and front differential leaks rarely. IAIK sees the same items across all-wheel-drive (xDrive) BMWs in general; they are drivetrain items, not engine items.

Reliability Verdict

Not established as a rating for the S63 family. For the S63TU4 Competition, IAIK, from our own shop, has never seen an engine issue and ranks it among the three most solid engines it sees; that is IAIK shop experience, not a failure rate. What the sources do show is a list of BMW recalls and service actions, tied to specific generations above. Those documents say what BMW found and fixed, and which builds were covered. They are not failure rates.

Power Potential

Not established. IAIK gives no output figures for modified engines. Factory output in the sources read is 555 hp (original S63), 560 hp (S63TU), 575 hp (S63B44T2) and 600 hp (S63TU4 in the F90 M5). BMW's S63TU4 training lists 617 hp for the F90 M5 Competition, in US units (ST1916, p.7 and p.9). IAIK warns against treating competition output figures or hardware from another M generation as evidence that a parts combination is compatible, and asks for the exact engine and parts arrangement to be recorded before any power target is set.

Cost of Ownership

Not established. IAIK gives no cost figures, and the BMW documents read list recalls and service actions without prices. This guide gives no yearly budget and no first-year catch-up estimate.