Most inline BMW engines are prone to a large oil leak caused from the oil filter housing gasket. This gasket is located between the engine block and oil filter housing. Oil is drawn from the oil pan via the oil pump and pumped through the block to the oil filter housing where it passes through the oil filter media. The oil is then circulated back to the block where it continues its journey to rest of the engine’s components. Where this oil leak differs from any other oil leaks such as the valve cover gasket or oil pan gasket is due to the fact there is full oil pressure behind this gasket, at times this can exceed 80+ psi!
Typically these gaskets begin to fail slowly, the gasket begins to harden and becomes less pliable, losing its ability to seal the engine block to the oil filter housing. The oil leak will progress very quickly and start to run down the drivers side of block, leaving a massive mess on the undertray and under the vehicle. The only remedy is to replace the gasket. At this time it is recommended to replace the oil cooler gasket as well (if equipped) which is located on the oil filter housing.
Have you run into this problem with your BMW? Do you need a hand in diagnosis and repair? Give us a call, we would love to give you some help.