BMW N54 N55 Turbo Burning Oil, Oil Usage 135i, 335i, 535i
car year: 2008 car model: 335i Coupe Dear Otto I have 335i 2008, and I noticed it is burning oil, almost a Liter of oil every 3000km. Warning message pop up, telling me that oil level is Low. My question is what would be quantity of oil in between Low and High level mark on the display? Could be malfunctioning Oil Level sensor ? What type of oil you recommending? Is there any DIY video available for 335i oil change?
The oil volume between the low and high oil levels is about 1-liter (or 1-quart). If you keep adding oil at similar intervals (due to the low oil level warning) and you are not overfilling, the sensor is probably correct, and the engine is indeed using the oil. The N54 (twin turbo) and N55 (single turbo) turbocharged 6-cylinder engines have a nasty habit of ingesting a fair amount of engine oil through the crankcase ventilation system. The stock oil separator is not up to the task of removing the higher volume of oil from the crankcase vent air, on these engines. Not only does this cause an alarming use of oil, but it also coats the complete intake manifold, cylinder head intake ports and intake valves with oil, which will eventually turn to carbon deposits. These carbon deposits disrupt the intake air flow and rob efficiency and performance.
BMW is well aware of this issue and has devised a walnut shell blasting procedure to clean out the deposits. Great!, you say, except that the general cost is about $800 and it needs to be done every 30,000 to 50,000 miles. Some engines show signs of deposit build-up in less than 20,000 miles.
Is there ANYTHING you can do about this? Well, yes, we’re glad you asked ……….
Burger Motorsports is offering an auxiliary crankcase ventilation oil separator kit. The Burger oil separator does a much better job of pulling the oil mist out of the crankcase ventilation airflow, greatly reducing (even eliminating) the oil usage problems (and carbon build-up) on these engines. The kit consists of an oil-separator/catch-can that is installed in the crankcase ventilation hoses between the valve cover and the intake manifold. Installation is straight forward and does not require any specialty tools.
As for oil type, we fully recommend the Liqui-Moly Vol-Synthese synthetic oils. The weight recommended by BMW, for these engines, is 5w-30 or 5w-40.