leaking valve stem seals?

[jazzvr]

My car wasn't starting but was still cranking over, pulled the plugs and they were drenched in oil! The car had been sitting for a couple months. I just wiped them clean with a rag cause I had nothing else and it started straight away. Im sure if I drove it everyday this wouldnt be much of a problem but I dont. Im guessing you have to remove the head to replace these?

[werd_103]

I don't think it'd be the valve stem seals. its more likely to be a leaky valve cover gasket.
what engine does this car have?

[wai]

More likely to be oil getting past the oil control rings on the piston.

The best test for leaking valve stem seals (or worn valve guides) is to go down hill on a trailing throttle and then accelerate. If you get a puff of smoke when you start to accelerate, this is a clear indication of worn valve stem seals or valve guides. The trailing throttle causes inlet vacuum which sucks oil past the stems and as you accelerate, this excess shows as a puff when you accelerate away.

You need to check this with the engine warm.

[werd_103]

sorry i thought you meant on the top of the plugs and you weren't getting any spark through.(has happened to me before) i guess im just not that bright today

[jazzvr]

How would oil be getting past the piston(travelling up) when the car is off? And sorry if this is a stupid question but what do you mean by trailing throttle?

Actually werd_103, you might be onto something. The only reason I checked the plugs is because the leads had oil on them and there was a bit of oil down the spark plug hole tube gap thingy(forgot the name).

[werd_103]

but my idea still doesn't make sense cuz if its on a VR (just a guess from you user name) the thin flat valve cover is so high that when the cars not running you shouldn't get any oil leaking out of it. All the oil should drain down. just thinking out load here :p

[wai]

How would oil be getting past the piston(travelling up) when the car is off? And sorry if this is a stupid question but what do you mean by trailing throttle?

You can get oil vapour getting past worn oil control rings after the engine has cooled down. It is highly unlikely that oil will come down the valve stem and coat the plugs when the engine is off. For it to do this, there would be a whole lot of other damage because the valve guides would be extremely worn. Also, for the plug to be oily, the combustion chamber would have to be fairly full of oil. Also, the oil would not be draining from the top of the cylinder head and so you would see a lot of oil when you look down the filler.

A trailing throttle is essentially very little throttle or none at all to generate high inlet vacuum. This will suck oil past worn seals or guides. When you next try and accelerate, the excess oil will be seen as the engine clears its throat.

[KKK VR6]

If you are burning oil, then it will blow grey or blue smoke.
If it only puffs out smoke when you
start it and when you take off from the lights, then it's valve stem seals.

Wai is also right with oil vapour thing an trail throttle sign.

[Jmac]

If you want to check how sound the engine is THE best test is a cylinder leak test. Thatll see how good the rings are. bad stem seals generally suck the oil down on start up so you get a burst of blue smoke. totally agree with the vapour, have a look at the lowest hose on the next turbo car you see, if you were to take the pipe off the oil will drip out, that was vapour once before, but back to the top cylinder leak test is the go
Ive done stem seals in place to by the way, but there is a thread on here already so wont go through it all again
Cheers
Jmac