I have a 2001 f-150 4.6 with regular cab and automatic. Since the truck was new I have an occasional large puff of smoke- fills half the garage- come from the tailpipe at start up. This seems to happen warm or cold and the only common thing to each of these occurences is that prior to the smoke event the truck was accelerated moderatlly to briskly. I have about 12000 miles on the truck now and it still does this. A trip to the dealer was no help. Any ideas?

 

What did they tell you at the dealer.....puffing smoke of any color can't be normal.