Oil on spark plug threads
- Thread starter Razor
- Start date
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If you've eliminated the valve covers.. and other simple leakage stuff from the outside..
Guides in my experience as long as the following other stuff has been looked at: If you have a blowby prob, or PCV probs - is the intake plenum area coated with oil from the crankcase or possibly a bad turbo seal? If you have an RJC power plate you can just pop off the throttle body pipe and look through the open throttle. If it's coated with oil, this could be part of the problem. It's easier to see with the plate because it tends to pool along the back edge of the plate.
If the motor sits for a while, and you start it back up, does a bit of blue smoke come out the exhaust? If someone else is driving the car and you let it coast a bit, does it puff a bit of blue on decelleration?
Lots of stuff it could be, but if the motor has some miles on it, and some of the other stuff above has been checked off, I would think guides.
I never did it on a turbo Buick motor, but have had mixed results with teflon seals on the heads on other motors that were NOT force inducted..
If you have stock heads and a pretty mild setup, the way the car came from the factory with seals on the intake and nothing on the exhaust works pretty well in my opinion. It lasts a long time.
Billy
Guides in my experience as long as the following other stuff has been looked at: If you have a blowby prob, or PCV probs - is the intake plenum area coated with oil from the crankcase or possibly a bad turbo seal? If you have an RJC power plate you can just pop off the throttle body pipe and look through the open throttle. If it's coated with oil, this could be part of the problem. It's easier to see with the plate because it tends to pool along the back edge of the plate.
If the motor sits for a while, and you start it back up, does a bit of blue smoke come out the exhaust? If someone else is driving the car and you let it coast a bit, does it puff a bit of blue on decelleration?
Lots of stuff it could be, but if the motor has some miles on it, and some of the other stuff above has been checked off, I would think guides.
I never did it on a turbo Buick motor, but have had mixed results with teflon seals on the heads on other motors that were NOT force inducted..
If you have stock heads and a pretty mild setup, the way the car came from the factory with seals on the intake and nothing on the exhaust works pretty well in my opinion. It lasts a long time.
Billy
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- Aug 11, 2002
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Obviously you have'nt been reading what the Alky Guru has been doing to that poor 3.8.
Razor, punishing the rest of us with your insane results is slowly coming back to bite you.
Not bashing, just jealous.
Razor, punishing the rest of us with your insane results is slowly coming back to bite you.
Not bashing, just jealous.
Well thats part of the you have to break eggs to make an omelette. The heads were ported and polished.. but bought used..mileage?? who knows.. They at one time had some 150 lb springs.. and a lot of passes.. but a local shop said they were fine. Same shop that told me they were flat.. and as soon as I blew a HG.. they needed .007 off at another machine shop.
I swapped the seals and it didnt get better. Tonite I pulled the worse one.. #2 .. and inspected the valve. Pulled the seal off, it has some play. So guides it is.
Once you eliminate the obvious.. very few things are left.
I'll have Bill at Champion fix'em.
Tho..the question still remains... do teflon seals seep a little?
Man i'd hate to waste some perfectly good HG's.. well tommorrow i'll turn up the squeeze and maybe can give me a reason to tear into it
I swapped the seals and it didnt get better. Tonite I pulled the worse one.. #2 .. and inspected the valve. Pulled the seal off, it has some play. So guides it is.
Once you eliminate the obvious.. very few things are left.
I'll have Bill at Champion fix'em.
Tho..the question still remains... do teflon seals seep a little?
Man i'd hate to waste some perfectly good HG's.. well tommorrow i'll turn up the squeeze and maybe can give me a reason to tear into it
- Joined
- May 26, 2001
- Messages
- 9,208
Not from inside......
Been thinking about this and do not see how bad guides or seals can get oil on spark plug threads.
On the exhaust side, gas is being blown out a high velocity. How can enough oil survive this toronado, flood the combustion chamber and go against the gas flow and out on the spark plug threads?
Coming in through the intake side it is swirled in the heat of combustion and there would have to be LOTS of oil to make it on the plug threads?
Are the tips of the plugs fouled? All plugs have oil on them or just some?
Been thinking about this and do not see how bad guides or seals can get oil on spark plug threads.
On the exhaust side, gas is being blown out a high velocity. How can enough oil survive this toronado, flood the combustion chamber and go against the gas flow and out on the spark plug threads?
Coming in through the intake side it is swirled in the heat of combustion and there would have to be LOTS of oil to make it on the plug threads?
Are the tips of the plugs fouled? All plugs have oil on them or just some?
I would say that it isnt anything to be concerned with. I've seen many cars do it. It can be unburned combustion. Unburned gas or oil from the cylinders getting squeezed out during the compression stroke.
Many things, but nothing that should affect performance unless the cylinder is burning oil. That can be bad since oil in the combustion lowers the octane and causes detonation.
Many things, but nothing that should affect performance unless the cylinder is burning oil. That can be bad since oil in the combustion lowers the octane and causes detonation.
I've changed thousands and thousands of plugs in my time....
....and I've often seen oil on the spark plug threads when there were no oil leaks anywhere around the spark plug hole, and no evidence of any excess oil in the cylinder or cumbustion chamber. I have no explanation, but I've not seen any detrimental effects either.
....and I've often seen oil on the spark plug threads when there were no oil leaks anywhere around the spark plug hole, and no evidence of any excess oil in the cylinder or cumbustion chamber. I have no explanation, but I've not seen any detrimental effects either.
