my '93 4.0 with 130,000+ miles seems to be developing a overheating problem, but its intermitant. yesterday i pulled my 1,000 pound box trailer 25 miles, engine temp was a little higher than normal but not enough to worry much about. later i drove to work, was fine on the way there. when i got to work i waited for the shift ahead of me to leave from a meeting, i sat for about 20 min with the a/c on high, actually fell asleep. woke up and the temp guage was higher than when i pulled the trailer, not pegged out to the far right but over halfway of the needle sweep. i rolled down the windows, turned the climate controls to heat and ran the blower on high for 5 min until the temp guage dropped to normal. on the way home, it was fine, coolant level is normal, was last changed 3 years ago when i put in a thermostat. when iwas pulling the trailer i was only going 55 in 4rth, wasnt really working it hard, and it wasnt hot outside. im wondering if the fan clutch could be not working or if its something with the water pump. both are oringinal. if i get a new water pump is the "severe duty" worth it or just a extra 20 bucks? usually if i have something with a cooling system issue, its either working or running hot, not a intermittant issue.

 

Thermostat not opening correctly Radiator plugged or impeller gone on pump.

 

I've always had the thermostat go bad before the water pump. Cheaper fix also.
Dave

 

Hey RACSAN-did this get resolved yet? I'm experiencing the exact symtoms and have already replaced the thermostat with no improvement...

 

its been normal since that day. weird. i pulled the trailer today and have had no issues, guage reading where it did before, maybe i just had a guage glitch.

 

I'm told that I have exhaust in the coolant/antifreeze. Major engine work but we're going to try this "BlueSteel" magical sealant(??) before we steer this Ranger to the junk yard.
Thanks for posting back. It bothers me that this is so intermittent-have great confidence in my mechanics integrity but sometimes wonder about capability...