94 Saturn Running Rich-Deposits on exhaust pipe
My 94 DOHC Saturn with 147k miles and it has been running fine but I have a noticeable amount of soot carbon deposits on the tail exhaust pipe. I have powerstack intake with a K&N filter. I am burning about a quart of oil every 3500 miles which from what I have read is not a lot for a Saturn. My catalytic converter was clogged and now replaced. I don't want to have to do it anytime soon again. I'm getting 35 MPGs since it has been warm out and 31 MPG when below freezing. Can anyone tell me how to stop the deposits or what is causing them?
if there's no servise engine light i would say have a scan done to determine the condition of the oxygen sensor(s)in the exhaust they may still be in spec but just barely
Possibly it could be that you are burning so much oil. One quart isn't too much to burn, but it could quite possibly be causing your "soot" deposits. You had to replace your cat because it was clogged? Could have been clogged by excess oil burnoff. The oil can be coming from a number of things internally. Try to remove the deposits from your tailpipe, and look to see if you have a lot of smoke coming from your pipe. If there is, reply. I would wager that perhaps your rings are worn or something else of that nature. It all depends on how hard you drive your car. Reply back with more details on it and we'll see if we can nail it down.
I do drive it reasonably hard. I drove it a very hard when I was younger. I've had the car for almost 10 years. Very common to redline and then shift. I never thought I would keep this car this long, but it has been so reliable and so much fun to drive. I wouldn't say there is a lot of smoke at idle, but possibly when accelerating. I did have to replace the cat because it was clogged. Would you think I would have to replace my rings? With 147k on it, do you think its worth to fix? The car is in great shape. Do you think the cat would clog up soon again? Thanks for you help.
I drive a 1991 Saturn SL2 and I have the same problem as you. I'm not positive if this is a problem or just a nuisance. I have a 3" catback on my Saturn and when I welded it all together myself I bypassed the catalytic converter to save costs of having to replace it. This is why I assumed that I get the carbon soot that covers my rear bumper. It covers my tailpipe and bumper but I can only see it coming out the tailpipe when driving @4000 rpms or more, so I was wondering when if at all can you see the carbon soot coming out the back? I had always assumed it was just soot that hadn't been reburned by my absent catalytic converter. I'm starting to think it just might be a common thing with this kind of Saturn, because I don't see and performance, maintenance, fuel/oil consumption, or reliability issues.
I can only see a little bit of smoke at night when there are tailights behind me and I am accelerating hard above 4,000 RPMs. I don't notice any soot on my bumper and I wash my car by hand. Maybe that's what to come. We have emmissions tests here so I cannot bypass teh cat or I would. I think the previous post is probably right about the rings being worn. I'll I can say is that this is one hell of an engine to be still running quiet, smooth and reliable for the torture I put it through in my years of driving.
Here's hoping you don't get busted for bypassing the cat, $100,000 fine (that is one hundred thousand dollars) or maybe that fine is just for shops.