Correct, but you'd be surprised as to how many people mistake cold start blue smoke for white smoke. The reason this confusion happens is that the condensation you get on a cold start mixes with the blue smoke causing it to lighten significantly. If there were a leak between the combustion chamber and the cooling system, the overflow bottle usually does just that...overflow.landyacht318 said:Wouldn't worn valve stem seals cause blue smoke, not white?
Actually, that's just the opposite of what you will find. If you see heavy whitish to brown deposits on a spark plug, it's an indication of coolant in the combustion chamber.B-300 said:If one has no deposits (steam cleaned) on it you can be sure there is a coolant into combustion chamber leak.