BMW Oil Filter Housing Leak – How to Replace Gasket – 6-Cylinder, M50, M52, M54, Etc.
This answer is applicable for many BMWs in addition to the one listed below.
I have a 1995 325is with 231,000 miles on the clock. It runs fine but recently it developed an oil leak between the oil filter housing and the Engine block. Will you send me, or tell me where I can find the correct procedure for replacing the oil filter housing gasket. Any help you can give me will be greatly appreciated.
A common oil leak on late model BMW 6-cylinder engines and MINI 4-cylinder engines is the small gasket between the oil filter housing and the engine block. The oil filter housing is the large aluminum casting that houses the oil filter and, on many applications, also mounts the alternator and the power steering pump.
This issue apples to the M50, M52, M52TU, M54, M56, S50, S52 and S54 6-cylinder BMW engines from the early ’90s through the late ’00s, as well as the MINI W10, W11, N12, N14, N16 and N18. With this noted, the most common models for leakage are the M52TU and M54 versions. The cure is to remove the housing and replace the gasket. Below, we outline the basic steps on how to perform this task. There are some differences between the specific engine models or chassis that they are installed in. This DIY procedure will assume an M54 engine in an E46 3-series, such as a 2002 325i.
Procedure, How to Replace Oil Filter Housing Gasket:
1) Remove the complete air filter housing.
2) Remove the oil filter cap to allow the oil filter housing to drain.
3) Unbolt the power steering reservoir bracket and move the reservoir aside. Some models may require removal of the reservoir. In this case, drain the reservoir and disconnect the hoses.
4) Remove the main serpentine accessory drive belt.
5) Disconnect the battery negative cable from the battery.
6) Disconnect the wiring connections from the back of the alternator.
7) Remove alternator cooling duct-work.
8) Remove upper and lower alternator mounting bolts and remove the alternator.
9) Disconnect the VANOS oil solenoid oil supply hose.
10) Disconnect wiring connectors from any sensors mounted to the rear of the housing, such as; oil pressure and/or oil temperature.
11) If the vehicle has an oil cooler (example; M3), disconnect the two cooler hoses from the housing.
12) Remove the six bolts securing the oil filter housing to the engine block.
13) Pull the housing away from the engine block. Note that we have not removed the power steering pump, so we cannot fully remove the housing from the vehicle. If you prefer to fully remove the housing, the power steering pump should be disconnected from the housing prior to removal before step 12).
14) Pull the old gasket from the grooves in the housing. Use a pick to assist, as the gasket may be hard and come out in pieces.
15) Clean the engine block and the housing (brake parts cleaner works well).
16) Install the new gasket into the grooved area on the housing and reinstall all parts in the reverse order.