I have a 4.6 and have water on the oil cap, but not in the oil , as i changed it this weekend . but i am adding about a gallon of coolent every 2 weeks . I have found that the coolant is going out of the exhaust ( white smoke ) but clears up when the truck warms up.....????? the truck has no loss of power , so I have ruled out head gasket. any help or thoughts would be greatly app. thanks in advance...

 

Welcome to the forum

The moisture on the cap could be from short trips and the engine not getting warm enough to evaporate the moisture in the crankcase or it has a bad PCV valve.

A gallon every 2 weeks? It could still be a head gasket that is blown and letting coolant into the cylinders but not the crankcase. If that is the and too much gets into a cylinder, it could fill with coolant and break the rod because coolant won't compress like air will.