944 S2 running rich and oil leak

Schocki · 02-24-2002, 07:40 PM

Hi guys,
My 1991 S2 developed a small (I hope) problem. The car is absolutely stock except for a conical shape K&N air filter. My wife just came back from a 350 mile trip and I noticed that the chrome exhaust tip is black. I used to live in Germany and drove the car hard an the Autobahn but the chrome tip was always clean :-).
The car always fires up with no problem but I noticed more black smoke from the exhaust while driving. Esp. under hard acceleration. Is my O2 sensor shot?
Furthermore the car needed 2 quarts of oil for the trip!!! But the car does NOT smoke blue and never did!? I noticed that the valve cover on the exhaust side of cyl #4 leaks and that the exhaust manifold is wet of oil at this spot. Could this be the oil problem? When the engine is completely warmed up and running at a constant speed does that mean that there is more oil leaking at this spot. I think it must be quite an oil leak if the exhaust manifold is still wet after such a long highway trip.
Thanks for any advice
Michael

1991 944S2 cobalt-blue and running rich
1972 911T Targa gemini-blue with 200 miles on a rebuilt engine and tranny and NO oil leaks :-)

AFJuvat · 02-24-2002, 09:29 PM

You probably found the source for your oil leak. I would get the valve cover gasket changed.

I would also have your air/fuel mixture checked.

AFJuvat

Z-man · Z-man's Garage

It does sound like the valve cover gasket. I had mine replaced in January.

How many miles on the car? It may be worth doing the seals/gaskets at this time, to keep your car running fine.

If you're around 100k, don't forget about the cam chain tensioner/guide. If that fails, you're in deep trouble!

-Zoltan.

Schocki · 02-25-2002, 04:33 PM

I think that the rubber gasket between the valve cover and the head is the source for the oil leak. I will fix it ASAP!
I will go the easy way with the richness and check the plugs, fuel pressure vacum and the CO prior to the cat first.
Thanks for your recommendations!!!
Schocki

Mrmerlin · 02-25-2002, 05:36 PM

Hi bro, hey it sounds like the oil leak has been found, for the running rich I would look into replacing any and all of the flexible couplings under the hood for the vacuum system also look at the fuel pressure regulator, for a vacuum leak.....
If your going to use engine gunk to rinse away the spilled oil be careful about getting water on the engine speed sensors in the rear drivers side of the engine, just cover this area with a plastic bag otherwise water will rinse into your clutch system and ruin the throw out bearing......Stan