Orange Juice

iTrader: (3)

so Im swapping out the plugs this morning and all the plugs have oil on the threads. The valve cover isn't leading. The plugs themselves look good, anyone seen this before or have any idea what it is?

RPM WS6

iTrader: (3)

Every time I've had oil on spark plug threads (only the threads, not the tip), it has always been from a weeping valve cover gasket.

If the tip/electrode is oil fouled, then you have a different problem.

fleetmgr

^^ yup, valve cover leaking.

Orange Juice

iTrader: (3)

I felt below the valve cover, nothing. Thread on "all" the plugs were heavy with oil. I have been told it is valve seals.

RPM WS6

iTrader: (3)

Are you seeing smoke from the exhaust on start-up?

Any loss of oil measurable on the dipstick?

Typically, leaking valve seals will allow a bit of oil into the combustion chamber after engine shutdown, and then you'll get a puff of smoke on start-up when this is burned off. I've had this before, got some pretty big oil puffs from the exhaust on start-up, but it was never enough to cause oil deposits all the way up the threads of the plugs (or foul the tips, but yours doesn't seem to have that issue either).

fleetmgr

You won't necessarily feel anything under the valve covers, as it accumulates in the spark plug wells over time, not over night. Bad stem seals will not do this.

Orange Juice

iTrader: (3)

The plugs as I pulled them out were wet with oil and the same all through the motor. The car has smoked at wot but I though this was a rich condition from the tune. I will see better tonight when it goes on the dyno.

RPM WS6

iTrader: (3)

I agree. All it takes is some accumulated oil around the outer edge of the spark plug in the plug well, and then it coats the threads as you unscrew the plug. To get that much oil all the way up the plug threads from the inside of the engine, you'd really need to have a combustion chamber full of oil under pressure, and oil fouled plug tips as well.

Again, you'd see some smoke on engine start-up with leaking valve seals, as the oil weeps into the chamber during engine cool-down. When I had this issue there was zero smoke at WOT, but a plenty-big puff on start-up.

If you are seeing smoke from the exhaust during WOT and it isn't due to overly rich A/F or carbon build-up, then I'd look beyond valve seals.

LS6427

iTrader: (2)

You need new valve seals.......only way to have oil on the threads.....and smoke at WOT......

When my valve seals were bad on my 436ci......I wouldn't get that puff at start-up......I did have wet raw oil on all of my spark plug threads though......also, when I went WOT from a steady cruising speed I would leave an initial HUGE blue-grey cloud of smoke.....then as I stayed on the throttle that cloud would slowly, over about 3-4 seconds clear up and it would be clear as I continued to accelerate.

When I hit the throttle that sudden decrease of pressure would suck oil through the leaky valve seals from the oil under the valve covers....going through my cylinders and giving me that huge initial cloud of smoke. As the pressure started to stabilize that cloud would clear up.
I removed the heads and had a valve job done on both heads.....problem solved.

I think if the valve seal leaks were really bad....you will get the start-up puff of smoke too.......as some people do.

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