So I have an 89 pickup and I'm starting to have overheating problems. I've had the truck for 3 years and it's always run great, but lately from when the truck starts to heat up the engine temp begins to climb and overheat. If I'm driving and need to get somewhere I turn the ac heat all the way up and that cools the engine back down. After a bit I turn the ac back to cool and the engine runs fine and is no longer overheating.

I am am just curious what the problem may be so I can fix whatever's causing the overheating in the first place.

any info will help!

 

A number of things can cause the overheating.

inspect radiator....mud and clogged up with bugs on the front?

If it only tends to overheat on the highway then replace the radiator.

When it gets hot, look under the hood and see if the upper radiator hose is bloated and extremely hot.....note if the lower hose is then normal looking and feels cooler to the touch. That would indicate a clogged radiator and replacing it will likely fix it.

Stock shroud and fan clutch?

Electric fans tends to cause more heating probs.

inspect thermostat....replace if it looks "old"

is the water rust colored.?