3blackbirds

Hey guys.

I believe I have a cam seal leak off the no. 1 cylinder. Both chain covers are wet on the bottoms. I'm going to replace the seals on both sides. How difficult is it to get to the cam shaft seal since I'm in there? I have an exploded view on a parts page of the cam. Doesn't "look" too hard to take apart. Any torque values you can lend me?

'90 964 C2

I just got done replacing the clutch and doing a tune up. Now i have this leak... figures.

Thanks!!

ian89C4

The left side shouldn't be too hard to get to. But remember, You need the special cam holder tool to take the cam gear off to get to the seals. If the engine is in the car I would imagine that it is very hard, but if it out it is not too bad. Also keep in mind that if you move the cam even a little bit while you are working on it and the cam is allowed to turn free of the timing chain (i.e. the cam moves and does not turn the rest of the moving bits in the engine) then you will have to re-time the entire engine. In it-self it is not to hard to time, but it can be time consuming. The right cover will be hard to get off as the AC bracket is in the way of two of the nuts. It can be done, but it is a pain in the a@#.
Also, watch out for the woudrough (Spelling?) key the helps hold the cog behind the chain sprocket in place. I forgot about them and one dropped down into the case, luckily I was able to get a magnet down there and got it. There are also shims behind that cog, make sure you put the right number back in. The pics below aren't the best, but hope they help a little bit.

Chain sprocket to the camshaft - 88 ft-lb
Timing chain housing cover to housing - 4 ft-lb

I can't seem to find the torque values for the three bolts that hold the seal cover behind the chain sprocket to the number one and number four cylinders (brass colored circular thing in one of the pics)

If I remember anything else I will toss it on here. I know there are a lot more people on here with more experience than me, hopefully they chime in.

Good luck!!!!

ChaseN

No no, you've got it all wrong.

That's a catastrophic oil leak - I've seen it before Jamie. You need a complete rebuild - probably to 3.8l (only PMNA parts will do, you know) with MoTec, just to be on the safeside. While you're in there go ahead and have the cams reground - I hear Elgin does good work. You'll probably need a set of larger headers (with heat exchangers, gotta keep the heat) to complement the rest of that work. Once you're done with that, I've got a line on a freshly rebuilt 993RS 6-speed (its still in Germany though, so you'll have to figure out shipping as well). Skip the 6-speed and it'll just leak again. I've seen it all before.

Its a rough diagnosis, I know. But you wouldn't want to go into this with so many misconceptions, you know? Uncle Sam's paying any ways, what the hell?

3blackbirds

Thanks Ian, that is great help. I'm going to tackle this thing in a few weeks. The motor is in, I just had the darn thing out 5 months ago. Didn't leak then of course...

Chase, I would have considered a rebuild to your recommendations, but I just put a down payment on a GT2 RS... maybe next paycheck!

ian89C4

Wow....you will have to post pics of your GT2 RS when you get it. That thing is a beast!

I hear you on not wanting to pull the engine, its a pain in the butt, try it with a C4

Let me know if you need more info, I will see what I can do.

Alan G.

It is not that hard of a job, but you will have to check the cam timing when you put it back together. It is worth getting all of the timing chain case seals and gasgets as a set.

ChaseN

That'll fix the leak

School me, where did I go wrong...my deployment take-home amount definitely did NOT equal a GT2 RS

3blackbirds

Army savings program!

Here are pics of what I'm looking at... cam seal leak or leaky head... (no head gasket) Sorry for the upclose and blurry.



Cylinder 1,



Cyl 2 and 3,

ian89C4

looks like a leaky head. Also the seal between the chain tensioner housing could be shot, that's what it looks like in the first picture. You may look at getting the head machined to accept the head seal ring. Also looks like the seals between the cylinders and the case are shot too. When I resealed my engine this past winter those seals were completely shot, they were hard as rocks.