After redoing the head on my 95 960, I am left with a persistant oil leak which seems to be coming from the rear cam seal. This is really frustrating because the car runs really well now and is so close to being 'right'. The oil comes from around the bottom of the cam position sensor housing and then runs down the engine onto the exhaust and oil pan.

Here's what I've done so far and my thoughts. I've replaced the cam seal three times. When I 'glued' the top section of the cam cover on, I had the seal in place- probably not a good idea, but this engine is a new experience for me after having owned red blocks for 25 years. Anyway, when I noticed the oil leak shortly after getting it running, I investigated and the seal was slightly cocked in the bore. So I took it out and replaced it. This time I pushed the seal as far into the bore as I could as the FAQ seems to suggest. Still leaks of course. After reading the green manual and looking at the old head, I realized that the seal doesn't need to go that far into the bore, because if it goes in that far it starts to crowd the oil return hole that is cast into the piece. So in goes seal # 3, but this time I was only going to push it in flush with the 'step' in the housing. Well, I got it ever so slightly cocked and didn't want to push it in any further. And it still leaks.

I'm not convinced that the slight misalignment of this seal would allow it to leak. My other idea is that I maybe didn't get enough of the 'goop' on that area of the cam cover and it is leaking at the seam near the seal and makes it appear that the seal is leaking. Maybe I'm overthinking it and just need to replace the seal again and be VERY careful to get it in just right-not too far in and straight. Thoughts or ideas from those with more experience with this engine?

I might have to agree with you, on that the sealer is leaking, though any angle on the seal would cause a leak. A couple of questions. Did you do a pristine job of cleaning the mating surfaces? Were there any nicks in those edges that should have been smoothed out? Was the sealant OEM or an aftermarket? Or could it be that there is too much sealer there and those return holes are clogged with sealant? Try to push a wire into the spaces. Did all of the bolts torque down? Those 10mm fine thread bolts do not take any over tightening, and the treads in the holes last for only a few cycles.

I think your only resort is to have the seal replaced with the tool to rule out seal seating, then if it still leaks, pull the head top, reclean, repair any bolt holes and re seal. Sorry, thats pain, and not what you want to hear.

DanR '94 964 336,000 miles (102,000 on the new engine)
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DanR

DanR- thanks for the suggestions. The mating surfaces were perfectly clean, used the OEM goop from FCP Groton, all bolts torqued down. I'm going to replace the seal one more time w/ some RTV on the outside and be careful. If that doesn't fix it, I'll just live with it. I am not up for pulling the cam cover again, etc. I'm crazy but not that crazy.

Be sure not to start the car for 24 hours after installing the RTV coated seal.

OK, thanks for all the help. Now I have another question. I was looking at two new rear cam seals I have. One is a Elring (OE, I guess) and the other is KOK? or something I haven't heard of. Here's the interesting part-the Elring is a single lip and the other is a double lip design. Seems to me that two lips are always better than one! LOL So, which one should I try?

The Volvo tool for this job installs the seal square and to the proper depth.It is difficult to install any other way.You may need to hire this out or obtain a tool.

Bill

Just bumping this to keep it from getting buried. Come on whiteblock buys, give me your thoughts! Thanks.