My brother owns a 98 sle with 3800 non supercharged engine. The problem he is having is if you let his car sit at idle for a few minutes and then drive of a big puff of white smoke comes out of the exhaust. I removed the spark plugs and all of them had a whiteish gray thick substance covering the electrode. I guess this is oil car doesnt lose coolant but it does lose oil what could be causing this problem this car runs fine no missfires. I changed spark plugs and pcv and the smoke isnt as bad now but i want to find out the cause.

Does the smoke smell oily or sweet? Is it white or does it have a slight blueish color? If oily and bluish it could be a leaking vale seal. If white and sweet it could be coolant. But you said coolant levels are fine but oil is disappearing. Can you post a picture of all the plugs and what cylinder they are from?

well all 6 of the plugs look like the pic the electrode was worn down really low too. the exhaust smelled oily before i replaced the plugs after i changed them i didnt get as much smoke i really small puff i have to replace valve covers and oil pan gasket too they were leaking.oh the exhaust smoke was white it only happened for a second i couldnt see if it had a blueish tint to it.

Is that the plug from you engine or one you found online that looks like it? Because that is classic ash fouling.

that was a plug that looks just like it but the center electrode on all of the plugs was almost burned down to the ceramic part the plugs that were in it were r44lts i put the platnum ones back in it. is there anything i can do to stop this from happening again

First thing you can do is take the platinum plugs out. They can't handle the heat and pressure of a supercharged engine. Use copper plugs like Autolite. If your getting a poof of smoke when you start the engine after sitting for a while it'* a valve guide. You would need to change those to correct the problem. From what your saying and the looks of the plugs I would guess that'* the problem.

lol ya definately remove the plats.... ive put in 2 sets and said forget this.... btw thats 2 sets in about 20,000 miles... i bought them at 10% over cost but that was still pricey for 10,000 miles of use... the autolights are the way most in the forum go... im about to put in a set myself

he said that it wasnt supercharged, but would that make a difference if u run a colder plug in an NA engine?

car is definately non supercharged whay would all of the valve seals go bad at the same time all of the old spark plugs were coated that way could oil be getting into the plastic intake i have heard those things go bad every once and a while.

I assumed it was supercharged because your sig says SSEi. Sorry, my bad. personally I don't see any easy way for oil to get threw the LIM gasket and into your cylinders. Only 2 ways for oil to get in there, threw the valve seals, and past the rings. Burning oil all the time suggests rings. Burning oil at the start up after sitting suggests valve seals.

As for the plugs, I still suggest a good copper plug simply because the price of a high end plug is a waste of money. There is no performance to be gained using those plugs.