White smoke on start up
Thread Starter
2nd Gear
Joined: Sep 2020
Posts: 2
Likes: 0
White smoke on start up
I just purchased a 1986 c4 corvette. It’s runs and drives great. 79k miles. When I start it up it blows some white smoke out of the passenger side exhaust. It lingers for a bit and goes away. If I turn it off and start it up again less smoke blows out than the first time. Never smokes when I’m driving it. Only on startup. What should I check to troubleshoot it?
Safety Car
Joined: Mar 2003
Posts: 3,583
Likes: 504
From: Indianapolis IN
Finalist 2020 C4 of the Year - Unmodified
C4 of Year Finalist (stock) 2019
Chances are your valve stem seals are shot. My '86 had the same issue when I purchased it. Replacing the seals fixed the smoke on start up. After 34 years, the originals more than did their job. Below are links to the ones I used for the replacement:
INTAKE: FEL-PRO SS72527 & EXHAUST: FEL-PRO SS72877
INTAKE: FEL-PRO SS72527 & EXHAUST: FEL-PRO SS72877
Intermediate
Joined: Sep 2020
Posts: 36
Likes: 15
From: Montreal
Be there done that. So, that's my best guess too. Quite a big job. I am not a professional mechanic but I did it after watching some video. Just make sure you don't drop a valve in your cylinder. I would suggest buying an inspection camera to make sure that your cylinder is at the top when changing the valve stem on that cylinder. Also, find out some forum talks about how to tighten your rocker afterward. No rocket science but if you don't do it right, you will have clunking sounds or no compression. If you need some help just ask me.
Advanced
Joined: Jun 2013
Posts: 64
Likes: 26
From: Cudahy, WI
2022 C4 of the Year Finalist - Unmodified
My 86 did the same thing replaced the valve seals and O rings put on roller rockers while i was there, i bought a valve keeper that you screw in the spark plug hole and hook to an air compressor
along with a valve spring tool the one that mounts on the rocker stud
about $100 in tools, and $200 in parts including the rockers to save what would be over $1,000 in labor for a shop to do was well worth taking the weekend to do the job
along with a valve spring tool the one that mounts on the rocker stud
about $100 in tools, and $200 in parts including the rockers to save what would be over $1,000 in labor for a shop to do was well worth taking the weekend to do the job
Cruising
Joined: May 2020
Posts: 13
Likes: 0
Just did mine this past spring. Not a mechanic but got her done. learned a lot along the way and did a few extras while i was in there (injectors, fpr, plugs).
having the right tools before you start makes a world of difference. Once I had the right tools all went pretty good. the toughest part for me was adjusting valves.
having the right tools before you start makes a world of difference. Once I had the right tools all went pretty good. the toughest part for me was adjusting valves.
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