Chevrolet Camaro Repair Question
Asked on January 5, 2007
Smokes, bad exhaust smell
1991 Chevy Camaro Z28 Miles:162,000 I just bought this car and he said it smokes a little bit on start up but will stop, after owning it for a week, it has not stopped smoking after start-up and there is a bad exhaust smell outside and inside the car. I don't know anything about cars but my first instinct would be an exhaust leak. I'm not sure exactly what color the smoke is, but recently it snowed, and after running the car for about 10 minutes, the snow was black. My wife seems to think it is a cracked head, but there is no coolant smell, the temperature is fine, no oil in the water or water in the oil, the oil pressure is fine, but it is also idling at 1500 rpm. I don't want to take it to a mechanic around here because i've been previously ripped off by atleast four of them in the past. Is it possibly a DIY problem? I noticed an oil leak and asked the guy who sold it to me and he said it was possibly the O-rings or valve cover gasket, would that make it smoke excessively and reek of exhaust? Or is that another problem entirely? Any suggestions would be greatly appreciated :( Please help.
Replied on February 3, 2007
Don't know what color smoke, but possibly since it was cold outside, the coolant temp sensor has shorted and is telling the computer it's 40 below 0. If that's the case, it will run very, very rich all the time. It will blow black smoke like a freight train. A coolnat leak in the combustion chamber would make white smoke almost like steam, and oil would be blueish and smell like oil. Sounds like you have an overfueling problem to me. That's where I'd start, with the coolant temo sensor. It's easy to replace, it's on ar near the thermostat housing. You'll have to take off the breather and air snorkel for access to it. I can't recall if the 91 still has the short aluminum plate over the front of the intake, if so, it'll have to come off as well. Good luck.