BMW M54 6 Cylinder Engine Oil Leak at Oil Filter Housing

This answer is applicable for many BMWs in addition to the one listed below.

Q
car year: 2000
car model: 323i
Against the block, below the oil filter, is there some kind of gasket or “O” ring where the oil filter housing meets the block?

A
We are finding that oil leaks from the gasket between the oil filter housing (and alternator and power steering mount) and the engine block are becoming quite common on the M54 6-cylinder engines (most 6-cylinders from 2000; 3-series through 2006, 5-series through 2005, X5 through 2006, X3 through 2006, Z3 and Z4 through 2005, except M and 3.5 turbo models).

The repair is to remove the housing/mount assembly and replace the seal/gasket.  This requires removal of everything that is attached to the mount.  The job can be done without removing the intake manifold, but if the manifold is removed, you do have more room to work. This procedure is covered in the Bentley repair manuals. Naturally, while you are “in there” you may want to replace the accessory drive belts (and possibly the idler and tensioner pulleys) since these will be removed anyway.

On an alternate note, we have also seen oil leakage on these engines from a housing plug (looks like a small freeze plug) on the rear of this same oil filter & mount assembly. The plug is not replaceable. The proper repair it to replace the complete assembly (!). In this case, we have seen success with properly cleaning the area and then applying an epoxy such as JB-Weld around the sealing area of the plug. Either way, the housing still needs to be removed for a proper repair …. and you’ll need a new gasket as noted above.

Oil filter housing to engine block gasket:

Bentley repair manuals: