1999 Tahoe rough idle and smoke from exhaust
#1
1999 Tahoe rough idle and smoke from exhaust
I own a 1999 Tahoe 5.7 L 4x4. Recently, it has been starting to idle rough after it is first started. Any idea what could be causing this issue?
Smoke has also been coming out of the exhaust as well when idling and accelerating. The smoke issue does not happen every time I drive the car, but it happens sporadically. It is white smoke, which I know isnt good. The car has been running fine besides the rough idle, so I really dont know what could be causing the issue. I looked it up online and it said that it could possibly be coolant mixing with fuel, but my coolant level has not gone down. Could it be related to anything having to do with the Catalytic converter? In August, I got a check engine light and when we checked it, the code was related to the catalytic converter.
I have owned 3 different Chevys with 5.7s and I've never encountered issues like these.
Smoke has also been coming out of the exhaust as well when idling and accelerating. The smoke issue does not happen every time I drive the car, but it happens sporadically. It is white smoke, which I know isnt good. The car has been running fine besides the rough idle, so I really dont know what could be causing the issue. I looked it up online and it said that it could possibly be coolant mixing with fuel, but my coolant level has not gone down. Could it be related to anything having to do with the Catalytic converter? In August, I got a check engine light and when we checked it, the code was related to the catalytic converter.
I have owned 3 different Chevys with 5.7s and I've never encountered issues like these.
#4
would a bad cat be the cause of either or both of these problems? I know that there is something wrong with the cat since I had the code read. I dont know the exact code, but it relates to a bad cat.
#6
alright well at least replacing the cat will solve one of the problems. I am having my mechanic look at it tomorrow and I will let you all know what the cause of the various problems are so that others who may experience the same issues can look at this thread for reference
#7
You may have either an intake manifold leak or a blown head gasket. The intake has to come off regardless once that is off you should be able to see if the intake gasket is cracked or blown. It is better to check with an automotive shop.
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#8
alright well at least replacing the cat will solve one of the problems. I am having my mechanic look at it tomorrow and I will let you all know what the cause of the various problems are so that others who may experience the same issues can look at this thread for reference
I have a 99 Tahoe having the same issue. Rough fluctuating idle and just got a mechanic to replace head gaskets because loosing coolant and fluctuating temp gauge and the idle. turned out needed two new heads and it still has the same idle fluctuating idle? Anyone have this issue and able to fix it? I’ve replaced idle control valve and egr. And my Tahoe doesn’t have Catalytic converters only the factory muffler.
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carid
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August 12th, 2015 5:42 AM