Leaking C2
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Joined: May 2002
Posts: 11
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From: Walnut Creek, CA
Leaking C2
I have a 1990 C2 with 112,000 miles. It is leaking oil from the cylinder base gaskets and the seam where the two halves of the cases meet up. I'm told a "re-seal" is about $3500. I'm torn between just driving it the way it is (it leaks about 1/2 a dozen 2' - 3" spots when parked and will burn smoke off the exhaust if it sits in traffic too long), do a re-seal, or go for an entire engine rebuild.
Any thoughts and/or advice would be appreciated. I've also considered buying a used engine and would like to hear any thoughts on that as well.
My previous car was a 1991 C2 and it didn't leak a drop. Is this a common problem with the 90 C2's?
Thanks!
Any thoughts and/or advice would be appreciated. I've also considered buying a used engine and would like to hear any thoughts on that as well.
My previous car was a 1991 C2 and it didn't leak a drop. Is this a common problem with the 90 C2's?
Thanks!
Race Car
Joined: Jun 2001
Posts: 3,706
Likes: 10
From: Virginia Beach, Va.
Leakage in that manner is a known problem for 1991 and below 3.6 engines...except for at the case halves. 
It is really up to you whether you can just "drive it" or go for a rebuild/replace. In my opinion, if you wanted to alleviate the leaks, redo the engine you currently have, I'm guessing it's the original...when you purchase a used/rebuilt unit, there's a possibility you're asking for a lot more trouble!
I live with my leaks and slowly take care of them. While my C2 does leak at the head to cylinder mating surface, which is fairly indicative of an early '91 C2, it has it's other leaks too. Recently I found the steel "L" shaped line that screws onto the case via a fitting on the right hand side just needed "snugged up" with a 36mm oil line wrench...cleaned up the area and so far it's remained dry.
Again, you have to decide whether or not you want to attack the problem. Chances are you are leaking from several little sources to make up the mess on your garage floor. ...and just to add my two cents in regards to your case halves leaking at the seam - I doubt that, but it's possible...shoot some engine cleaner up there when the engine is warm, not hot, hose it down and check it out after a drive to work and back. You may find a different source other than you though, BTDT!
It is really up to you whether you can just "drive it" or go for a rebuild/replace. In my opinion, if you wanted to alleviate the leaks, redo the engine you currently have, I'm guessing it's the original...when you purchase a used/rebuilt unit, there's a possibility you're asking for a lot more trouble!
I live with my leaks and slowly take care of them. While my C2 does leak at the head to cylinder mating surface, which is fairly indicative of an early '91 C2, it has it's other leaks too. Recently I found the steel "L" shaped line that screws onto the case via a fitting on the right hand side just needed "snugged up" with a 36mm oil line wrench...cleaned up the area and so far it's remained dry.
Again, you have to decide whether or not you want to attack the problem. Chances are you are leaking from several little sources to make up the mess on your garage floor. ...and just to add my two cents in regards to your case halves leaking at the seam - I doubt that, but it's possible...shoot some engine cleaner up there when the engine is warm, not hot, hose it down and check it out after a drive to work and back. You may find a different source other than you though, BTDT!
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Joined: May 2001
Posts: 5,864
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From: TX
As Jeff mentioned, pre-1991 964 engines didn't have a cylinder to base gasket, and in a small percentage of engines can leak. Besides living with it, there are three basic options to fix the cylinder leakage: 1) the Porsche fix, with new cylinders, machining, gaskets and studs, or 2) Use alternate sealing rings (niresist), or 3)a "new" used engine. If it were my problem, I'd opt for option 1 or 2. If you do one of those, also replace your rod end bolts with stronger bolts (Raceware, ARP are two brands). From 3.2L engines on, Porsche reduced them to 9mm (previously 10mm), so over-reving can over-stress them with ugly consequences (important if you track your C2). Also check the condition of your valve guides. Replace any seals while the engine is out, ie power steering pump seal, timing chain cover seals, etc. Option 3, as Jeff points out, may bring new problems.
