I have a 91 2600i 4wd 105k. Last year in May it started blowing alot of white smoke from the exhaust. After talking to my mechanic, he said the head gasket was probably blown. He recommended having it towed to his shop so if the head wasn't cracked, not driving it would hopefully save it. When he tore the engine apart, he said the head was ok. He also resurfaced it.
The truck ran excellent til just this past august. One day when I started it, a puff of white smoke came out the exhaust. I kept an eye on it. It wouldn't do it all the time, and there was no consistancy to the symptom. I monitored the antifreeze loss for 3 weeks, and the level went from the highmark on the resevoir to below the low mark.( readings were taken while the truck was hot. Never once did it over heat. Never. I took it back to the mechanic and he pressure tested the cooling system. The system never lost pressure. I'm confused. Then when I started it to take it from him, I reved it up a little and the white smoke apeared. You guys probably know, its got that sweet smell. Now he's confused. He's going to rip it apart on monday, but I was hoping to get some info here. I've been doing alot of research on this engine(2.6L I think it's a mistubishi engine) and they said it was notorious for blowing gaskets.
Sorry for rambling. Any info anyone has would be greatly appreciated. I read the head bolts need to be retourqed after so many miles to help prevent head warpage and blown gaskets. Please help! Thanks so much

As a former owner of a 1989 B2600i 4x4, I can assure you that your 1991 has a MAZDA engine in it. I highly suggest that you have the head Magna-fluxed (checked for a crack).

Also you did not mention whether your mechanic reused the head bolts when he changed the gasket last time. The head bolts are a one time torque type of bolt, So it is possible that the head was not tightened to spec.

Good luck with your truck.

PS: While you have it apart that far, I suggest checking the wear and the tension on the balance shaft chain and the timing chain and tensioners. That is what wiped out my truck at 109K miles.