Valve Seals?
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Joined: Jan 2010
Posts: 82
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From: Richardson Texas
Valve Seals?
My 86 is acting bad and I'm on a tight budget. I have been checking everything to fix my smoke issue. It likes to smoke all the time now and I need help. Did a compression check and all was good. When I did a vacuum test, I found the issue. Needle was going nuts and gauge was telling me burnt valve. My question is this. Would the valve seals leaking also give me a bouncing needle? The motor has approx 30k on it and when I changed the intake gasket the motor looked brand new inside. Any advice would be great. Thanks
Drifting
Joined: Apr 2008
Posts: 1,565
Likes: 2
From: Sparta Mo.
Valve seals are easy enough to change, but a bad valve seat won't cause smoke, it'll make it back fire and pop either out the exhaust or out the intake. (which ever one is burnt)
I'm also not sure a bad seal would affect the intake vacuum. Bad valve guides could certainly do it though. A certain amount of "jiggle" in the vacuum is ok. Especially if you have an aftermarket cam with a fair amount of overlap. Is it jumping around alot? I would try the easy stuff. Is the PCV valve clogged? How about the breather? If bad valve guides are the problem, (which would make it smoke like a freight train) you could use the umbrella type valve seals and it would fix it temporarily. If you put new seals in it and it stops, you need valve guides. (machine work in the heads) The seals will just prolong the inevitable.
I'm also not sure a bad seal would affect the intake vacuum. Bad valve guides could certainly do it though. A certain amount of "jiggle" in the vacuum is ok. Especially if you have an aftermarket cam with a fair amount of overlap. Is it jumping around alot? I would try the easy stuff. Is the PCV valve clogged? How about the breather? If bad valve guides are the problem, (which would make it smoke like a freight train) you could use the umbrella type valve seals and it would fix it temporarily. If you put new seals in it and it stops, you need valve guides. (machine work in the heads) The seals will just prolong the inevitable.
Thread Starter
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Joined: Jan 2010
Posts: 82
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From: Richardson Texas
Thanks for the help. I guess I will just swap the heads and call it a day. I did change the PCV, IAC, TPS and full tune up so all the hoping for that to fix it was wishful thinking.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
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From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
smoker
Your problem is your intake gaskets. change them again, use really good ones, and use "the right stuff" around the intake ports as well as the water passages, and it will go away.
If you used MR gasket gaskets, they are too large, and will not seal all the way around.
I have a set of stock E86 heads ready to go for $150 plus shipping.
If you used MR gasket gaskets, they are too large, and will not seal all the way around.
I have a set of stock E86 heads ready to go for $150 plus shipping.
Thread Starter
Advanced
Joined: Jan 2010
Posts: 82
Likes: 0
From: Richardson Texas
Your problem is your intake gaskets. change them again, use really good ones, and use "the right stuff" around the intake ports as well as the water passages, and it will go away.
If you used MR gasket gaskets, they are too large, and will not seal all the way around.
I have a set of stock E86 heads ready to go for $150 plus shipping.
If you used MR gasket gaskets, they are too large, and will not seal all the way around.
I have a set of stock E86 heads ready to go for $150 plus shipping.
