Re: Head gasket? Lotta Milky stuff..
Reply #1 –
He probably figured that since rich usually turns the spark plugs black and sooty, lean should make them clean and white. Actually, coolant leaking into the cylinders will do a very good job of "steam cleaning" the plugs, as well as the tops of the pistons, sometimes cleaning off all the deposits that help the rings seal.
The cooling system is always under pressure, and coolant will get sucked into the cylinders past a damaged gasket, get vaporized into steam, then blow out wherever it can, even back into the cooling system and out the overflow tank. The coolant can also help wash the oil off the cylinder walls, letting the rings wear out faster, allowing normal exhaust pressure and/or coolant and/or steam into the crankcase.
Also, when the engine is turned off, the coolant will keep dripping into the cylinders until the pressure is gone, and then will slowly leak past the rings into the crankcase oil.