Blue smoke
Thread Starter
4th Gear
Joined: Mar 2006
Posts: 4
Likes: 0
Blue smoke
I have 1979, 350, L82. The car looks as though it is leakining a little from thee valve covers at the rear.
When I start it up, a wiff of blue smoke appears then go away.
It only does it after it sits for awhile.
Any suggestion what might be the cause?
When I start it up, a wiff of blue smoke appears then go away.
It only does it after it sits for awhile.
Any suggestion what might be the cause?
Melting Slicks
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
If oil is leaking from the valve cover onto the exhaust it will cause it to burn off when the exhaust heats up...is the smoke coming from under the hood? If this is what is happening, there should be significant visual evidence of the oil. R&R the valve covers and replace the gaskets. (BTW there are only two valve covers).
Drifting
Joined: May 2003
Posts: 1,634
Likes: 2
From: Melbourne, Victoria, Australia, the World
Frankie,
Sounds like valve stem seals are letting a bit of oil into the intake/exhaust. It is only noticable on start up when the oil has had time to accumulate.
Replace the seals and check the guides at the same time. If the guides are sloppy then it's time to do a valve job.
Be aware of the "while I'm at it I'll......" syndrome, you may end up with a big block in there.
Sounds like valve stem seals are letting a bit of oil into the intake/exhaust. It is only noticable on start up when the oil has had time to accumulate.
Replace the seals and check the guides at the same time. If the guides are sloppy then it's time to do a valve job.
Be aware of the "while I'm at it I'll......" syndrome, you may end up with a big block in there.
Melting Slicks
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
If it is puffing out the exhuast I agree that the valve seals are the likely culprit. If you have good compression all around, you could probably change the seals with the heads on and solve the problem. If compression is down, RHD '68 L89 might just have point on the big block.
Drifting
Joined: Apr 2003
Posts: 1,323
Likes: 2
From: Castle Hills Texas
I went through this on my 80 as well and it turned out to be valve guide seals. Next thing I knew, there were new heads and a new cam in there, as well as true dual exhaust. It fixed the problem.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Race Director
Joined: Sep 2005
Posts: 18,640
Likes: 121
From: Farragut,TN
I would do both. compression check and seal replacement. the blue smoke you see in your description is coming from bad valve seals or worn valve guides. the compression check will give you an idea of the piston rings and valve condition.
Thread Starter
4th Gear
Joined: Mar 2006
Posts: 4
Likes: 0
Originally Posted by RHD '68 L89
Frankie,
Sounds like valve stem seals are letting a bit of oil into the intake/exhaust. It is only noticable on start up when the oil has had time to accumulate.
Replace the seals and check the guides at the same time. If the guides are sloppy then it's time to do a valve job.
Be aware of the "while I'm at it I'll......" syndrome, you may end up with a big block in there.
Sounds like valve stem seals are letting a bit of oil into the intake/exhaust. It is only noticable on start up when the oil has had time to accumulate.
Replace the seals and check the guides at the same time. If the guides are sloppy then it's time to do a valve job.
Be aware of the "while I'm at it I'll......" syndrome, you may end up with a big block in there.
