Oil Pan or Filter Housing Gasket?

[Roscoe458]

Really don't wanna have to replace the oil pas gasket if I don't have too. But it sure looks like the oil pan is leaking. If the oil filter housing gasket is leaking, can it drip down and appear to look like the pan gasket is leaking? Anyone experienced this before, or have some insight?

[sijray21]

Really don't wanna have to replace the oil pas gasket if I don't have too. But it sure looks like the oil pan is leaking. If the oil filter housing gasket is leaking, can it drip down and appear to look like the pan gasket is leaking? Anyone experienced this before, or have some insight?

If the oil filter housing gasket is leaking it can definitely make it seem as if the pan is leaking. I had this happen. Try to clean it as best as you can or take it to a reputable shop for diagnosis and then decide for yourself. I ended up changing the oil filter housing myself and it solved 95% of my problem.

[Mr Bingley]

Put the car up in the air in a well ventilated area. Place several large overlapping sheets of cardboard under the car all around. Do no do this over a surface that you care about staining like a new concrete pad. Using brake parts cleaner, thoroughly spray down the pan, block, transmission, cross brace, mounts, steering rack, etc. (wear safety goggles and dish washing gloves). Clean it until it's spic and span. Spray from the top judiciously at those areas of the block you can see--avoid hoses, connectors, etc. From underneath (close the hood to prevent over spray onto painted surfaces) really soak it down. The whole process should take several cans. Wipe down what you can with shop rags and allow it to dry completely--an hour or more depending on the weather. The entire underside should be clean. After driving it, inspect--oil won't travel upwards, so it is leaking where the wet begins--trace the wet to the source. Fix the leak. Clean it again local to the leak, and it should stay clean thereafter.

[R Shaffner]

+1 to ^. The only addition I have is to spray WD-40 or similar on any sections that are heavily gunked up, or thick with oil and dirt. Let the WD-40 soak in for a few minutes to loosen things up. Then I start with the brake cleaner.

[Randy Forbes]

Not knowing the specific engine you have in your car, I will add to the above points that the S54 engine has an oil pressure regulating valve about mid-height at the extreme rear RH side of the engine block. While the valve itself never seems to present a problem, the O-ring that seals between it and the block has been know to leak on several examples.

Historically, I replace the whole valve/O-ring assembly. This can be done in situ.





PRV seen at extreme LH end of block, just below the outline of the cylinder barrel.



ALL S54 owners should keep this in mind; I don't know if the M54 engine is similarly equipped...

[rf900rkw]

>I don't know if the M54 engine is similarly equipped...

No. Contrary to the extremely popular belief that all Z3s are the same, only the S54 has the high pressure VANOS with it's own pump and regulating system. If an M54 has a wet oil pan, replace the oil filter housing gasket. Because, you know, gravity and such.

[Roscoe458]

Thanks for the info! I got her clean like suggested. Gonna drive her awhile and see if I can get figured out. When I come to a conclusion I will let yall know.

[KBH22102]

2001 S54 with 87K miles. I’ve been chasing a slow oil leak. I have changed the valve cover gasket and the CPV (used a Viton o-ring), but I still have the leak. I’m going after the oil filter housing gasket next. The videos I have found online are for E46 M54 engines. Is the process appreciably different for the S54? Anything unusual I need to be aware of and any other ‘while you’re at it’ tasks I should take care of? Is the S54 mechanical fan and clutch just as prone to grenading as other Z3 fans, and should it be proactively replaced? I have a persistent whine from my power steering even after changing my reservoir, all the lines, and doing > 10 fluid exchanges so I will likely just replace the PS pump while I am there. I also have a set of Rogue Engineering power pulleys to throw on.