BMW N63 engine is an eight-cylinder engine from BMW automobile manufacturer, which replaced the BWM M60 and M62 engine series, with technical characteristics that meet the high requirements of the modern automotive industry. It was developed according to the concept of “Efficient Dynamics”, which implies a combination of economical operation of the engine and convenience in driving. The N63B44 engine is the first mass-produced biturbo V8 from BMW. Previous atmospheric V8s developed from 286 to 360 hp. But here the working volume was reduced to 4.4 liters, and the power increased to 408 hp.
BMW makes confident steps in aspiration to create energy-consuming and ecological engine, though it is not so simple to do it. This series can safely be called the engine of the new generation – the system of direct fuel injection, and, what is noteworthy, two turbochargers placed in the cylinder block camber is an innovation first developed by BMW engineers.
A new aluminum cylinder block with an all-new lightweight crank was developed for the N63. The cylinder heads are redesigned, with a revised arrangement of the intake and exhaust ports. Inlet valves are 33.2 mm in diameter and exhaust valves are 29 mm in diameter. N63 cylinder heads are equipped with modernized Bi-VANOS/Dual-VANOS intake and exhaust camshaft timing system. The timing drive utilizes a toothed bushing chain.
The turbocharging system is realized with two Garrett MGT22S turbochargers working in parallel and placed in the block camber, there is also the exhaust. The maximum boost pressure of the N63 is 0.8 bar. The arrangement of turbochargers and main catalysts in the space between the rows of cylinders (in the V-block camber) allows to achieve a high level of power at an optimal layout and weight, as a result – the usual intake and exhaust manifolds have changed places. This arrangement allowed the use of larger diameter and shorter piping lengths, minimizing pressure drop on both the intake and exhaust sides.
However, this arrangement of the exhaust manifolds has become a big problem with this motor: the space between the cylinder heads, in which the exhaust is enclosed, heats up to 900 degrees Celsius. This temperature “boils” the oil and reduces the life of the main components of the N63 engine.
Siemens MSD85 control system
In 2012, the engine was modernized and received the prefix TU to its name. In the finalized powerplant used pistons with modified bottom, new connecting rods, adapted crankshaft. The cylinder head is designed to utilize the Valvetronic III intake valve lift system (as on the N55), as well as direct fuel injection (TVDI). The N63TU camshafts are new compound camshafts. The VANOS timing system has been modernized and its adjustment ranges have been expanded. The cooling and oil supply system has been improved, the intake has been modified, the exhaust has remained the same. The turbocharger pump wheel has been slightly modified. Engine management system was replaced by Bosch MEVD17.2.8.
N63B44 engine
The engine has been produced since 2008 and is used in several model lines of BMW cars to the present day. It has a cylinder displacement of 4.4 liters (4395 cc) and produces 402 hp at 5500-6400 rpm. Torque is 600 Nm at 1750-4500 rpm. The maximum possible revolutions of the engine crankshaft is 7000 rpm.
The BMW N63B44 engine is fitted to vehicles with the 50i index:
- 2008 – BMW X6 xDrive50i (body E71)
- 2009 – BMW 750i/750Li sDrive/xDrive (body F01/F02)
- 2011 – BMW X5 xDrive50i (body E70)
- 2011 – BMW 550i sDrive/xDrive (F10/F11 bodystyle)
- 2012 – BMW 650i sDrive/xDrive (F12/F13 bodystyle)
N63B44TU engine
BMW N63B44TU engine is a 2012 modification, more powerful than the previous one – 450 hp at 5500 rpm. Gas distribution mechanism of the engine has received a stepless system of changing the valve lift Valvetronic. Torque has also increased and amounted to 650 Nm at 1750-4500 rpm.
The engine BMW N63B44TU is installed on cars with the index 50i:
- 2013 – BMW 650i Gran Coupe (body F12/F13).
- 2013 – BMW 750i/750Li sDrive/xDrive (body F01/F02).
The N63B44 engine was the basis for the BMW S63 turbocharged sports motor, for the X6M, X5M, M6 and M5.
Problems of N63 motors
For 10 years of operation, experts and technicians have come to the opinion that if you intend to buy a BMW with a biturbo “eight”, it is better to buy immediately with a faulty motor. N63 has so many diseases that it will break sooner or later. And here it is important not to overpay for a car with a “bouquet” of problems and malfunctions, the elimination of which is very expensive.
Oil consumption
Among experts there are different opinions about N63, they note the main problem of the majority of BMW units – oil consumption. Based on the feedback of car owners, the new engine during the first 100 thousand kilometers does not really lay on oil, keeping within the declared norms of consumption. But after the milestone of 100 thousand kilometers, the consumption increases noticeably to an average of 1 liter per 1000 kilometers of mileage. The reason for the consumption is oil caps, clogged oil drainage rings, grayed compression rings, as well as turbines, crankcase ventilation, injectors. Oil consumption diseases are characteristic of many turbo motors, among them the N63 engine series: the spring function of the ring is weakened – a common design flaw, this is the reason for the N63’s voracity. High operating temperature, plus the use of “manufacturer-recommended” engine oils, accelerate coking of piston grooves and provoke loss of ring mobility – oil is successfully “squeezed” into the combustion chamber.
The second most common possible cause of “oil spoilage” is the material of the cylinder block. “Alusil” still suffers from childhood diseases in the form of corrosion, the formation of caverns. In this case, only replacement of the block will help, otherwise up to 1 liter per 1000 km will go into such a cylinder.
Weak silumin block
Forced biturbo engine with high operating temperature has an extremely heat-loaded silumin block, devoid of a hint of safety margin. Threads on about one in ten blocks sometimes fail to re-tighten and threads leak (the higher the mileage, the greater the likelihood, of course). There is a certain probability of lifting the cylinder head during further operation in case of further use of factory threads.
Oil caps
The oil caps of the cylinder pairs (3-4/7-8) closest to the engine shield turn into plastic in 3-4 years due to overheating. The others turn plastic a little later. Replacing only the oil caps is successful in about one out of ten cases. In addition, oil overgrows the seats of inlet and sometimes exhaust valves, which in the future still sooner or later leads to reassembly of the cylinder-head.
Fuel injectors
Piezo injectors manufactured by SIEMENS-VDO, since the release have been updated several times only by factory number. On average a new revision of the injectors came out once a year, which is a lot even considering the inertia of a major manufacturer. All for the sake of trying to solve their main problem – probable uncontrolled leakage leading to so-called “hydrostroke”, which simply bends connecting rods.
This problem can befall a BMW biturbo eight after a long period of idling without driving, or a long period of depressurization of the power system. For example, this is almost guaranteed to happen during an overhaul, or even a medium overhaul when the fuel line is disconnected for an extended period of time. Once reinstalled, the injectors begin to “overflow” in an unpredictable algorithm, within hours of being put back into service. Mercedes, by the way, hastily switched to electromagnetic injectors after experiencing similar overflow problems (which BMW itself has expectedly done in recent models).
Spark plugs
The spark plugs of the N63 motor are also a source of problems. This is the first BMW engine model with three revisions of spark plugs. It turned out that the plugs are too brittle: the electrode can break off. In addition, at high pressure in the combustion chamber, the plugs of the first samples are simply unable to “break through” the fuel-air mixture. Even brand new plugs from the box can give ignition misses. That is why, for M-motors, BOSCH company produces reinforced plugs in the same form factor. They are guaranteed to be normal.
TNVD
From 2008 to 2014, three revisions of the fuel injector manufactured by BOSCH were released for the BMW N63 motor. The pump itself does not cause any particular problems (unless it starts knocking noticeably), just the car drives dumber and dumber, which is only noticeable when comparing the response (time/pressure) of a new pump and a pump with mileage. Replacing the model with a new one gives a sharper response to the throttle and then it becomes obvious that the car has regained its lost sharpness. A strong recommendation is to replace the old fuel injector with the current model. As of 2017, the cost of the most recent pump revision is 10 times off retail on the recall.
Vanos valves
The solenoid valves on the Vanos system are inherently jammed when depressurizing (disconnecting). The second revision of the valve (released 10/2012) seems to be free of this problem. With patience, the valve can be forced pumped or revitalized with a couple weeks of daily emergency operation.
Vanos mechanisms
VANOS mechanisms have so far been left unchanged by the manufacturer almost from the very beginning of production. The manufacturer as if does not notice the problems with them, which is expressed in the fact that with the passage of time and wear (and it is well noticeable by “floating” adaptations) the plastic protective cover, which is constantly boiled in oil, is sometimes torn off from the mechanism. Usually it is torn off at the moment of cold start. The cover is chewed up by the chain drive teeth, deformed and floats in the cylinder head. Or, what is worse, it breaks into pieces and clogs the oil inlet. About every 10th N63 engine is already full of plastic stuff – pieces of Vanos mechanism cover.
Supercharger cooling pump
A common problem is a leaking charge air cooling pump. This metal-plastic product works with temperatures up to 120 degrees and after idle time for a couple of weeks it simply “shrivels up” and starts to drip. Simply because shriveled not moisturized for a long time seals. By the way, the same fate and problems at the second additional pump, if it is available in the set.
Turbine
After 5-6 years of operation, the turbine loses radial/axial alignment and starts to shave chips off the housing. It has been modified four times during production (new ones even come with a modified housing). Every second car has an oil-filled intercooler and wet pipes.
Due to the location of the turbines in the block collapse, where the normal operating temperature reaches 300 degrees Celsius, “boiling” engine oil, which is fed to the turbine bearings and drained from the cartridge through thin-walled metal tubes. The boiling point of engine oil rarely exceeds 280 degrees. The oil simply clogs and clogs the tubes. Fresh oil simply begins to go into one of the parts of the turbine: it burns in the exhaust or goes into the elements of the intake manifold.
Oil getting into the intake manifold floods the pressure and temperature sensors, of which the N63 motor has four (two for each side).
High Temperature Effects
Everything that is constantly in contact with high temperature, deteriorates and crumbles. For example, numerous vacuum tubes and pipes in the cooling system suffer from excessive heat. The plastic housings of turbine pressure reducing valves also crack.
Throttle valve
Electromechanical throttles of the BMW N63 motor at a mileage of about 50-60 thousand kilometers can begin to jam. In case of jamming at low speed, the engine enters emergency mode, which cannot be switched off by anything but a brief removal of the battery terminal. A good precursor of the emergency state of the throttle is nervous engine operation when warming up. Characteristic shaking of the N63 motor can also indicate problems with the injectors.
The timing chain sprocket
The chain drive sprocket wears out in a few years: its teeth are simply “eaten”.
Crank liners
BMW motors have almost always had problems with connecting rod liners. The manufacturer unsuccessfully calculates their strength and wear resistance, which eventually translates into a lot of problems with the engine. The liners rotate, especially against the background of oil change with intervals of more than 8000 km. In this case, even branded BMW oil accumulates dirt, which seeps under the liners. In general, the longer the oil change interval, the higher the chances of hearing the characteristic engine knock. For N63 motors, a revision of the crankshaft and all liners: connecting rod and main liners was released in 2011.
Piston group
In 2011, a modernized piston group was released, designed to avoid the problem of clogged piston grooves and loss of ring properties.
It’s hard to avoid problems with the BMW N63 motor, especially in sluggish traffic with plenty of uncounted engine hours. Malfunctions with BMW’s biturbo V8 can be postponed. It is important to change oil every 5-7 thousand kilometers.