Oil On Spark Plug

[skinner2k3 3]

Nipped out to try and find reason for a missfire the car developed on the way home from a track day.

 

Tried to start it and it ran like a pig and sounded pretty awful too, decided it wasn't firing on all cylinders, removed the plugs and one of them was soaked in oil......arse!

 

I am guessing head gasket, but could a valve stem seal fail badly enough to do that?

Edited June 19, 2011 by skinner2k3

[steve@cornwall 100]

Nipped out to try and find reason for a missfire the car developed on the way home from a track day.

 

Tried to start it and it ran like a pig and sounded pretty awful too, decided it wasn't firing on all cylinders, removed the plugs and one of them was soaked in oil......arse!

 

I am guessing head gasket, but could a valve stem seal fail badly enough to do that?

 

 

Last one I had like that had the rings embedded in the piston crown!! --- Hope that makes you feel better

[skinner2k3 3]

Much better

 

I guess I wont know until I whip the head off. Something to keep me busy I guess

[rallysteve 22]

do a compression test on it first, could be valve guide/seal

 

 

 

Steve

[skinner2k3 3]

I intend to do one this weekend.

 

Going to take the plugs out and turn it over by hand first, have a good listen. Assuming that's ok a compression test and then put some good plugs in and see if she fires.

 

The more I think about it the more I think it may be a valve seal. Having sat there for a week it would have had plenty of time to leak through and run onto the plug.

 

Has anyone actually tried pressurising the cylinder to hold the valve shut and change a seal with the head on?

[smithy 1]

I intend to do one this weekend.

 

Going to take the plugs out and turn it over by hand first, have a good listen. Assuming that's ok a compression test and then put some good plugs in and see if she fires.

 

The more I think about it the more I think it may be a valve seal. Having sat there for a week it would have had plenty of time to leak through and run onto the plug.

 

Has anyone actually tried pressurising the cylinder to hold the valve shut and change a seal with the head on?

 

 

used to do it on the lease cars when i was apprentice,to be honest it is a bit of a pain in the arse and on my own car i would always opt to have head off to clean the valves and re lap while changing seals.

[skinner2k3 3]

Is there much specialist kit required?

 

Can it be done another way, with normal tools?