My friend has a '92 Blazer v6 4x4. The 4wd used to work and then one day wouldn't. You can hear the transfer case engage and when I crawled under the truck I could see the shaft going into the front case spinning. Any suggestions on what it might be? Also he says that the truck has suddenly lost alot of power and is blowing smoke at start up and a little after. Is this a blow head gasket or maybe a manifold gasket. The reason I am asking is becasue he bought another car and is going to junk the blazer but if I can fix this stuff I will buy it from him for a few hundred. Thanks for the help.

come on no one has any ideas? 27 views and no input...

my 87 did the same thing (4wd) it was a cracked hose since mine is vacuume fed, fixed the line and is all fine now. now its blowing smoke too, so I want to know the answer there to.
chris

What color's the smoke? That will tell you what it's burning.
White = coolant (antifreeze)
Blue = oil
Black = excess fuel (rich)