thanks for the reply's.the truck has a 22r.smoke comes out of the exhaust.if it was black and a diesel it would look cool.but it's not.it has 138000miles on it.maybe i will pull the head and check it out.smoke is white and smells like antifreeze and humid.the good thing about it is when it does it makes it easy to find exhaust leaks <img src="/forums/images/graemlins/lol.gif" alt="" />.so do you think i should have the head rebuilt while it is off?