5.4 headgasket problem?
It's got 8000 miles and I've changed the oil several times before.
Just today, when I started the van there was a huge puff of white smoke (not steam) that came out the tailpipes.
I had recently changed the coolant from Ford Yellow (G-05) to Prestone Green/Distilled.
Is this a sign of headgasket failure or???



