An experienced BMW mechanic diagnosed a long-time oil leak on my 1997 528i as coming from the gasket seal between the oil filter housing to the block. However, he quoted 5 hours labor to replace the seal, which sounds like it must be a very difficult job. I do not see this task covered in the Bentley manual. This is similar to the posting on December 17, 2011 asking about the torque values for the bolts.
Can someone describe this task: is it very difficult? Can it be done without removing the intake manifold or any other major component?
I answered my own question. Apparently this is such a common repair needed on BMWs that several people have posted instructions for various models and years. The posting most relevant to my car can be found at www.bmwtips.com, where the job for a 1998 528i E39 is described quite well.
The answer to my question is that the airbox and alternator needs to be removed. On some models the expansion tank, radiator fan, and power steering pump also need to be removed.
The repair is not described in the Bentley E39 or E46 manuals.