exhaust though the engine.... hmmmmm!

Looked at my fiancee's car today and it is running like there is a definit loss of compression in one of the cylinders. Took out the spark plugs and found that one of them (cylinder 2) had the entire end burned off (the parts of the plug between which the spark is produced was completely gone). As the car ran, you could see a little white smoke coming through around the pcv valve and if you took the oil filler cap off, tons of white smoke came out. I was told that it was probably a burned valve. Would a burned valve cause all this smoke to go though the motor or do you think it is more that the piston is burned up some how allowing exhaust gases to leak down into the oil pan, then up though the motor. If its only the valve, I can replace the valve, but if its the piston burned up, we are going to dump the car and go get a new one. can anyone help on what they think it might be. Also, of course, when you rev the motor a little with the filler cap off, the smoke increases with the rmps. THanks for your help.

-Billy

White smoke? I'd lean towards a head gasket. But it's possible that cylinder 2 misfired so long, it washed the oil off the cylinder walls and scored the wall, causing low compression and blow-by..

You could have a detonated piston, more likely it dropped a valve and it cracked the head or block on the next compression stroke. If you do keep it, get a whole new engine, rebuilt or a low mileage boneyard one.

Bob

did the smoke smell sweet like coolant, or pungent like burning oil?