I have a 91 explorer with a 4.0. after the engine is warm and the truck has been shut off for more than 3 minutes and is restarted it blows what appears to be steam out the tailpipe for about 5 to 10 seconds. The head gaskets were just replaced 4 days ago and there is no oil in the water and no water in the oil. The engine has not overheated and the water pump is pumping.It is not losing any water that I can tell.
Before the headgaskets were replaced it was doing the same thing but stopped for 3 days after the work was finished and then started again. The white smoke does not smell like coolant it just smells like exaust.
The engine does not smoke at all when cold and only smokes after it has been warmed up then shut off for a few minutes. After it runs for about 10 to 15 seconds the smoke stops and does not smoke at all while running.
I would be grateful to anyone that might give me some idea as to what might be going on, thanks

 

It could be condensation inside your exhaust. Fuel has a certain amount of water in it that will burn off. Could be condensing inside your muffler or exhaust somewhere and then blowing out. Try using a better gasoline from a major supplier (like BP). They have very little water in them...

 

Do not worry this is normal working condition, absolutely no prob with that kind of smoke. If it had another color it would be ok to worry but not in this case.