When the N63 4.4L twin-turbo V8 arrived on the scene in 2008, it was unquestionably one of the most advanced V8 engines ever produced. In fact, it still is to this day. BMW experimented with a new “hot vee” engine design which mounted the turbochargers and exhaust manifold between the cylinder banks, being the first engine of its kind. While the N63’s hot vee layout significantly reduces the overall engine packaging, the design also comes with its fair share of issues.
Most significantly, the excess heat created between the cylinder banks and near the cylinder heads causes crucial components, like valve seals, to wear prematurely, leading to excess oil consumption. Oil consumption is so bad on some N63 engines that BMW owners started multiple class action lawsuits to receive compensation for the faulty design. In this article, we’ll take a look at the N63’s tendency to drink oil by the liter, what causes the issue, and what you can do about it.
What Causes N63 Oil Consumption?
It’s important first to understand why the N63 is such a thirsty engine. The primary reason boils down to the engine’s overall design. Twin-turbo V8s tend to be massive engines. That isn’t exactly a shocker, as engineers have to find room to fit two banks of four cylinders longitudinally while also saving space for the turbos and all of their auxiliary components. For that reason, it would be hard to cram such a large engine in a vehicle as small as a 5-Series, so BMW came up with a new design.
The “hot vee” layout that they settled on places the two turbochargers, along with the exhaust manifolds, between the cylinder banks on top of the engine. That not only saved space but also increased turbocharger efficiency. However, that design also leads to a major negative consequence, a lot of heat. Since the massive heat generated by the turbochargers collects so close to the cylinder heads, it steadily wears out gaskets and seals within the heads, allowing oil to sneak by in areas like the valve seals.
The oil then leaks into the combustion chamber where it is burned off. Since the issue is caused by the design of the engine itself, BMW hasn’t developed a true way to remedy the issue completely. While BMW did attempt to improve the oil consumption issue on later iterations of the N63, with a new oil catch can design on the N63TU and thermal shielding around the cylinder heads on the N63TU3, the issue carried across all iterations of the engine, albeit less extreme on the later models.
- Low engine oil iDrive alert
- Low engine oil when checking oil level through iDrive
- White/bluish smoke from the exhaust
- Engine burning more than 1 quart per 750 miles
The symptoms of excessive oil consumption are pretty straightforward. The primary symptom is an alert by the iDrive that your engine oil is low. In some extreme cases, N63 owners would get an alert that engine oil was low as frequently as every month. In fact, outside of the service bulletins for oil consumption, there is even a dedicated service bulletin covering the frequent illumination of the “oil level low” iDrive message itself.
Since the N63 is known for its oil consumption issues, it is also a good idea to check your engine oil frequently through the iDrive’s electronic dipstick, unless you have a newer N63TU3 engine which returned to a physical dipstick. Since there is no physical dipstick on N63 and N63TU engines, you have to navigate to the “Check Oil Level” section in the iDrive, making sure the oil is at operating temperature and the vehicle is on a level surface.
It is important to also mention that the N63 engine also has other issues that can cause excessive oil consumption outside of its overall design. These engines are also known to have PCV failures which can also lead to oil burning off in the combustion chamber by being recycled through the intake manifold. For that reason, the PCV system is a good place to start before jumping to conclusions about faulty valve stem seals.
First-generation N63 engines had the worst rate of high oil consumption of all of the engine variants. With the introduction of the N63TU in 2012, the engine received a modified oil catch can and a new valve stem seal design which helped with the oil consumption problem but did not remedy the issue completely, with many TU owners still complaining about oil consumption.
The same situation was still the case on the N63TU2 as well. In 2018, the N63TU3 arrived with improved thermal shielding for the crankcase and the cylinder head which seems to have improved the problem dramatically. Here are the vehicles that were most affected by oil consumption issues:
- E70 X5 xDrive50i (2010-2013)
- E71 X6 xDrive50i (2009-2014)
- E72 ActiveHybrid X6 (2009-2011)
- F01 750i/xDrive Sedan & ALPINA B7 (2009-2012)
- F10 550i/xDrive Sedan (2010-2013)
- F13 650i/xDrive Coupe (2011-2012)
- 2013-2019 BMW 750i/750Li
- 2013-2018 BMW 650i
- 2013-2019 BMW 650i Gran Coupé
- 2013-2016 BMW 550i GT
- 2014-2016 BMW 550i
- 2017-2019 BMW M550i
- 2018-2019 BMW M850i
- 2014-2019 BMW X5
- 2014-2019 BMW X6
- 2018-2019 BMW X7
Excessive Oil Consumption Fixes
Since the problem stems from the design of the engine itself, there isn’t much you can do to stop oil consumption completely. However, there are some steps that you can take to lessen the amount of oil that your engine burns.
One of the major steps that you can take is to change your oil more frequently with an oil with lower Noack volatility while still making sure that it is still LL-01 approved. In the owner’s manual, BMW recommends changing your oil every 10,000 miles or 12 months which, in my opinion, is frankly ridiculous. Reducing your oil change interval to 5,000 miles will ensure that the oil retains its lubricity and viscosity until your next oil change, which can greatly reduce oil consumption.
Noack volatility is also an important metric to look for as it measures the evaporation loss of lubricants in high-temperature service. The lower the value, the less likely the oil is to burn off due to the high temperatures that the N63 subjects the oil to. Oils like Castrol Edge 5W-40 have low Noack volatility while also being a slightly heavier oil which also helps reduce oil consumption.
Oil Consumption Class Action Lawsuit
At this point, there have been so many technical service bulletins and class action lawsuits about the N63’s oil consumption issues that they are hard to keep track of. BMW also issued a Customer Care Package for N63 owners, but that revolved more around other issues like injector failure and battery discharge.
The first class action lawsuit that actually had an impact on N63 owners experiencing oil consumption issues was launched in 2016 and called Bang v. BMW. The resulting settlement outlined that BMW would have to offer a number of complimentary services to determine the severity of the oil consumption on each engine, while also offering free oil changes for vehicles that applied. The stipulations are that the vehicle must either be less than 10 years from its in-service date or have less than 120,000 miles on the odometer, whichever comes first.
To check the severity of the oil consumption, BMW performs an oil consumption test on the engine by filling the oil, sealing the oil cap, and measuring the consumption after a certain mileage. If the vehicle burned at least 1 quart of oil in 750 miles, it failed the test, leading to a repeat of the test. If the vehicle fails the test twice, it is eligible for a new long block.
However, depending on mileage, a portion of the cost will have to be paid by the customer. For vehicles with 50,000 to 60,000 miles on them, owners are responsible for 5% of the cost, from 70,000 to 80,000 miles, the out-of-pocket jumps to 30%. For high milers with over 100,000 on the odometer, BMW will only pay 25%.
While it isn’t an ideal solution, the settlement took a bit of the sting out of replacing the engine completely out of pocket.
It Seems Like As Long As The N63 Is Around, It Will Be Burning Oil
While the N63 is an innovative engine with plenty of performance to offer, it has experienced its fair share of problems. So many in fact that it is often considered one of the worst BMW engines of all time. While I don’t personally agree with that, it might be because I haven’t owned one. It would be extremely annoying to add a quart of oil every 750 miles.
There’s no doubt that the original N63 had it the worst, as the changes made to the N63TU, N63TU2, and N63TU3 made a slight improvement to the oil consumption issue. With that being said, even the newer engines are known to burn oil as well. The issue stems from the engine’s hot vee design itself, making it nearly impossible for BMW to resolve completely without redesigning the engine entirely.
Unfortunately, there is only so much that you can do to help reduce the issue. More frequent oil changes using low Noack volatility oils that are BMW LL-01 approved is the best way to limit oil consumption yourself. Outside of that, there isn’t much else that can be done. With the success of multiple class action lawsuits, BMW has finally agreed to aid with the issue, performing oil consumption testing and significantly reducing the cost of an engine replacement in certain circumstances.
That doesn’t really help those who are experiencing the issue with over 120,000 miles on the clock though. In that case, it might just be worth living with the issue or getting rid of the car altogether. For more information about the BMW N63 engine, take a look at our engine page which covers all aspects of the engine from common problems to popular modifications.