Left Bank Smokin?
Thread Starter
Racer
Joined: Jan 2010
Posts: 375
Likes: 21
From: London Ontario
Left Bank Smokin?
My '72 SB with 96,000 miles always puffed a little blue smoke at startup so this winter I thought I would tackle the problem
Compression test - good results (for 96K)
replaced original valve seals with umbrella type seals
So I've driven it about 200 miles this spring and now the left side smokes blue CONSTANTLY ( worse than before) and the right side doesn't at all!
Any comments would be a great help for me:
Should I have used both Umbrella/O ring Seals?
Compression test - good results (for 96K)
replaced original valve seals with umbrella type seals
So I've driven it about 200 miles this spring and now the left side smokes blue CONSTANTLY ( worse than before) and the right side doesn't at all!
Any comments would be a great help for me:
Should I have used both Umbrella/O ring Seals?
Racer
Joined: Aug 2006
Posts: 330
Likes: 3
From: Wellington, New Zealand
I had the same issue with my 1974 115,00 miles, replaced seals with standard O ring type and problem was solved. I actually wanted to use umbrella seals but was unsure which ones I needed to order, so just went with the O rings.
Pro
Joined: Aug 2013
Posts: 591
Likes: 3
From: Monroe Washington
I've got a fresh 383 built stroker... <2500 miles or so on it so far... And will get the occasional blue puff on startup as well.. Interested to see what responses you get here, and as I diagnose my own solution I'll try to update as I find out info... Figure I'll go talk to the local corvette/engine experts and get some feedback as well...
Thread Starter
Racer
Joined: Jan 2010
Posts: 375
Likes: 21
From: London Ontario
Thanks for the input
I did another dry/wet compression test with good results
after running it today I did find a puddle of Oil on the intake manifold under the throttle linkage
I'm going to pull the intake and try a new gasket
Has anyone experienced a leaking intake causing Blue smoke?
I did another dry/wet compression test with good results
after running it today I did find a puddle of Oil on the intake manifold under the throttle linkage
I'm going to pull the intake and try a new gasket
Has anyone experienced a leaking intake causing Blue smoke?
Racer
Joined: Jan 2005
Posts: 499
Likes: 0
From: Enfield CT
I had a internal intake leak that caused the car to burn oil on the left side of the engine.The gasket split at the intake and sucked oil up from the lifter valley.To check for a internal intake leak disconnect and seal the pcv grommet hole with tape.Now place a piece of plastic wrap over the other valve cover hole breather hole and rev the engine up.If the plastic wrap sucks in you have a internal vacuum leak
If you have oil leaking from the intake I would replace the gasket anyway
If you have oil leaking from the intake I would replace the gasket anyway
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
I had a internal intake leak that caused the car to burn oil on the left side of the engine.The gasket split at the intake and sucked oil up from the lifter valley.To check for a internal intake leak disconnect and seal the pcv grommet hole with tape.Now place a piece of plastic wrap over the other valve cover hole breather hole and rev the engine up.If the plastic wrap sucks in you have a internal vacuum leak
If you have oil leaking from the intake I would replace the gasket anyway
If you have oil leaking from the intake I would replace the gasket anyway
What he said. It's your left side intake gasket, it's pulling oil into the cylinders from the head-to-intake joint. As long as no ill-conceived machine work was done to your engine recently it shouldn't be too terribly difficult to correct with a good set of new, properly-installed gaskets.
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,599
Likes: 7,046
From: New Or-leens Loo-z-anna
The umbrella seals were very brittle and I also had an oil puddle at the intake on the driver's side......new valve stem umbrellas seals and intake gaskets cured the smoking (and oil consumption/1 qt. at 3,000 miles).
Pro
Joined: Nov 2013
Posts: 730
Likes: 37
From: Catoosa Okla
Thanks for the input
I did another dry/wet compression test with good results
after running it today I did find a puddle of Oil on the intake manifold under the throttle linkage
I'm going to pull the intake and try a new gasket
Has anyone experienced a leaking intake causing Blue smoke?
I did another dry/wet compression test with good results
after running it today I did find a puddle of Oil on the intake manifold under the throttle linkage
I'm going to pull the intake and try a new gasket
Has anyone experienced a leaking intake causing Blue smoke?
A rule of thumb taught to me by an old timer goes like this:
If it smokes under constant acceleration, it's the rings. If you wind the engine up driving down the road and let off the gas in gear, then let it wind down on it's own, then hit the gas pedal again. If it smokes then, it's valve seals/valve guides, ect. Under deceleration, bad valve seals of guides will "draw" oil into the cylinder and smoke when you hit the gas.
