Blowing smoke
Thread Starter
Instructor
Joined: Aug 2010
Posts: 101
Likes: 1
From: Moriches NY
Blowing smoke
1991 c4 automatic 94K miles, will start to blow smoke at around 85 MPH (stops after dropping down below 75 MPH). I know the rear main seal & lower intake are starting to leak (winter project). Was wondering if this is a sigh of other issues (valves, seals, rings). Any ideas?
Melting Slicks
Joined: Jun 2001
Posts: 3,444
Likes: 0
White smoke is water getting into the combustion chamber and creating steam. Blackish/Blue smoke is oil buring.
If Blackish / Blue it could be valve seals and/or guides. It could be rings. Do a compresion test and see what your dealing with.
If whitish, it's most likly a head gasket or worse case cracked cylinder wall.
But verify it is coming out of your exhaust by having someone follow you. If it just coming out from under the car, then it could be your leak hittinig the exhaust or something like that.
If Blackish / Blue it could be valve seals and/or guides. It could be rings. Do a compresion test and see what your dealing with.
If whitish, it's most likly a head gasket or worse case cracked cylinder wall.
But verify it is coming out of your exhaust by having someone follow you. If it just coming out from under the car, then it could be your leak hittinig the exhaust or something like that.
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
What does your oil look like Golden or Black? If it looks like Chocolate Milk Shake, you might have other issues like a Head Gasket leak. If you run a compression test, you will know whether it is leaking in the cylinders or whether it is valve guides.
Thread Starter
Instructor
Joined: Aug 2010
Posts: 101
Likes: 1
From: Moriches NY
1991 c4 automatic 94K miles, will start to blow smoke at around 85 MPH (stops after dropping down below 75 MPH). I know the rear main seal & lower intake are starting to leak (winter project). Was wondering if this is a sigh of other issues (valves, seals, rings). Any ideas?
Melting Slicks
Joined: Mar 2003
Posts: 2,898
Likes: 0
From: Oklahoma City Oklahoma
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