Fan exhaust works, but the heater does not warm up. I plan on replacing the thermostat to start with. Does it matter what type of thermostat I use (160 F of greater)?

 

Go greater than 180. I dont remember what stock is but do that. Changing temps only confuses the puter. Only other thing i could think of would be to maker sure the lines to the heater core are not kinked and make sure your coolant isnt really nappy. Spooge in the coolant can plug/restrict the core. Good luck

 

if that don't work change heater core, really easy and little $$

 

IS it?

I know my '89 was, but I thought they changed it after '91

 

It kind of depends...does the engine warm up, but not the heater? That would pretty much rule out the thermostat. Double check to make sure the valve in the heater line is opening and letting warm water in. If so, then it could be a clogged heater core. But, if everything is cold, it is likely the t-stat.

 

The engine will "warm up" with a 160 degree thermostat, but not enough to provide much heat when it is cold out. The stock thermostat is around 190 and that is what is needed for heat in cold climates. I had a 160 when I was in Florida but had to change it out to a 190 when I moved to Colorado or I had no
heat.

 

He did not metion if the engine warmed up or not---i just changed one out on my 1985 4x4 and it was stuck open ,yes the indication was engine not warming properly.-TR