BMW N63 Turbocharged V8 Engines

N63 twin turbo 4.4 V8 in an X5
Chronology
The N63 was the follow on from the normally aspirated N62 V8, it was only available as a twin turbo 4.4. From 2008 onwards it was used in the E71 X6. It was adopted in 2009 for the F01 750i and in 2010 the F10 550i. The X5 version entered service in 2011 and the 650i N63 was sold from 2012.
In 2012 the N63TU replaced the N63 in all the models which had it up until that point. The newer engine had around 10% more power and torque.

N63 showing twin turbos and direct injectors
Design
In a radical departure from past designs the exhaust was now in the centre of the V8 valley and the intakes on the outside. This was more efficient in terms of packaging but caused many new issues managing so much heat in one area as the catalytic converters were fed from the same central area. Air to water intercoolers were used for the first time by BMW as they were more efficient in this configuration. The water intercoolers could reduce charge temperature by up to 80C, BMW had seen half this from some previous air intercoolers.
This engine used double VANOS but not Valvetronic. This was also done in the N54 turbo engine as Valvetronic is of less benefit in a turbo charged engine. Also the N63 used direct injection and it's far easier to package the cylinder heads for that if you don't have the Valvetronic gear in the way.
The N63 used similar block and bore technology to the N62 and had a cast crankshaft and conrods. The timing chains used new tooth-roller technology for lower friction.
The turbos were fairly small Garretts, this had the advantage of fast spin-up and reduced turbo lag - especially when combined with such a short exhaust manifold. Boost pressure was around 11psi although diverter valves could reduce this to smooth things out.
The direct injection system was similar to that on the N54 and could run at up to 200bar pressure.
In 2012 the M63TU Technical Update was released. This engine went back to using Valvetronic as a suitable packaging approach had been found to accommodate it along with the direct fuel injection. The TU had lighter Mahle pistons, forged conrods and crank, a catch can system to replace the OSV (finally!) and the fuel system and VANOS from the N55. There was also improved component cooling and a second coolant pump (one mechanical and one electrical).
For the TU the turbos design was modified and the diverter valve system was no longer needed thanks to the use of Valvetronic which couldn't generate much intake manifold vacuum. In the original engine there had a been a problem if the throttle plate shut suddenly.

Catalytic converter emerging from the engine valley!
Variants
Code | Size | Power bhp@rpm |
Torque lb/ft@rpm |
BHP/ litre |
Torque/ litre |
Made | Bore x Stroke |
Timing | VANOS | Used in |
N63 N63TU |
4.4 | 400 @ 5500-6400 440 @ 5500-6000 |
450 @ 1750-4500 480 @ 1750-4500 |
91 100 |
102 109 |
2008-12 2012 on |
89x88.3 | Chain | Dual | 550i, 650i, 750i, X5, X6 |

N63 in a 650i coupe.
Problems
The N63 has a thirst for engine oil due to the piston ring design, apparently the N63TU isn't so bad.
The N63TU has a catch can, so no more clogged oil separator valves! The N63 doesn't, so the valve will clog.
These are direct injection engines so are prone to carbon build up on the backs of the intake valves, the N54 and N55 have the same issue. You may have to remove the intake manifolds to clean the intake ports every 40k miles.
There is an awful lot of heat generated by this engine. BMW have gone to great length to manage it but only time will tell if it's worked reliably.
BMW revised the oil change interval to 12,000 miles but 10,000 would be safer. Good clean oil is vital to the life of these turbos. These engines use a fair amount of oil between changes and you MUST regularly check the level!
There were TSB's (technical service bulletin) regarding chain stretch, direct injector replacement, the vacuum pump, breather lines and the MAFs.
A modified injector released in 2015 is meant to be more reliable and can substantially improve economy. Apparently the heat of the engine caused rubber seals on the injectors to fail. It also possible for the injector nozzles to foul.
Early models had problems with the starter motor, the solenoid could stick. Not easy to get at on this engine.
The new roller chain can fail. Owners have found chain parts on top of the cylinder heads but without the chain having failed (yet).
These was a recall on the high pressure fuel pump but generally they seem to be reliable.
This engine has the same valve stem seal problem as the N62. If you're seeing clouds of smoke once the engine has warmed up this may be the cause. New seals are available, they're a better design and should cure the fault once and for all. They can now be fitted without removing the engine from the car or removing the heads from the engine.
Due to heat issues this engines kills batteries, especially in hot climates. BMW tried high tech Absorbent Glass Mat (AGM) batteries but the problem didn't go away. There was a technical service bulletin (TSB) to replace them every oil change in some countries.