I have a leak from the bottom of the engine. Seems to leak 1/2 down the dipstick then stop. Then this weekend I had the car on ramps after 2 months after my last oil change and it leaked some more. Which seal could it be. The rear main seal or the oil pan gasket? Any way of telling. The oil seems to leak down the sides of the oil pan and onto the drain plug.

Second thing to check is the condition of the PCV system. Pressure build-up inside the crankcase will find a release through the weakest seal.

The weakest seal might be the rear main seal (worst case), the front main seal, the intermediate shaft seal or the cam shaft seal.

Another possibility, depending on the year of the Volvo to which you are referring, is the seal on the rear side of the camshaft cover.

All the seals on the front of the block, C-shaft, I-shaft, front main, may or may not leak to the spot you see. The rear main seal or the cam cover seal might.

The cam cover seal has a history of catastrophic failure; rapid loss of oil while running. It can be hazardous to the engine. Check with engine cold by reaching on that rear spot with a clean paper towel to see what's what back there.

Second thing to do is be sure the PCV system is clean, including the oil separator box.

Good Luck,

Bob

:>)

Thaks for the reponse. The dealership told me it was one of those 2 seals. I have a 1988 240 wagon. I know the valve cover gasket is leaking so I'll try that first.

I also have a tiny oil leak . The oil collect at the lowest bell housing nut where it joins to the gear box.I have not been able to trace that leak to any where i.e. It seems to be generated from that nut itself. The gear box and the bell housing surfaces are flush with each other however there is kind of notch/space at the location of nut where the surfaces meet. It seems that oil comes from that .Everything else seems dry. What seal it can be.
Sorry to jump in like this with my issue .
Regards
Gopesh

I know this makes little sense, but trust me - I lived it, and it leaked like you described. After chasing an "oil leak" all over the engine - replaced front seals, cleaned out the flame trap lines, they needed it anyway, valve cover, etc., I was about to take my 91 240 in to a mechanic for the rear seal when someone suggested I check the aluminum transmission cooling lines. Bingo. There is a small clamp that holds the lines to the frame near the bell housing had rubbed almost through one of the lines - no hole, but it was so thin fluid "weeped" through the line wall. When mixed with the aluminum "dust" the transmission fluid, which was due for a change, looked like old oil. You could not see the leak without removing the clamp. Installed new lines, replaced the trans fluid, and the "real main oil leak" disappeared.

Turns out this is a pretty common problem - the clamp loosens just slightly and over time the weeping starts.

Good luck!

Dave
91 240 original owner