87000 miles. Auto trans. Dual cab. 4x4. Babied.

Help!

Picked up the 250 from the ford dealer. The truck has been running hot with the AC on. Runs at the "m" range of "normal" typically and has for the ten years I've had it. So the ford dealer folks talked me into a new water pump and thermostat... $960 later.... I picked the truck up and within a mile I notice the temp gage is up at the "l" end of "normal". So I pulled over and shut it off. Waited 20 minutes. Turned it back on. And it was now down at "o" end of "normal". I decided to leave it at my sisters house which happened to be seven short blocks from that location. Down hill.. And in that short drive to my sisters house the temp gage went up and down wildly.

It's never done this before. I dropped it back off at ford later that evening....


The heating issue I had before is the truck would run hot when the ac is turned on. A side note is the ac, when it's on blows cold when going flat or down hill, but shuts off when the truck is under load going up a hill. Eg vacuum related. The ford people said they could not replicate the issue...

Any ideas?.

 

The temperature gauges in these trucks are notoriously flaky. The best solution is to install an aftermarket gauge that actually gives readings in degrees. After installing mine, I could observe my factory gauge reading from just before "N" to over the "R" with only a 5 degree actual difference, and to make matters worse, the factory gauge would give different readings when the actual temperature stayed steady.
And check the thin white vacuum line that runs over to the HVAC components on the passenger side firewall. That's the usual culprit with the AC issue you mention.

 

there probably wasn't a thing wrong.the stealership took ya for a ride.as stated above,get yourself a real temp gauge first.

 

So the dealer called me today to say that the water pump that they installed was defective and they are going to install another new water pump.... I don't believe that a new water pump would create an issue like this. Any thoughts? I called back to speak with the service manager. He said he is going to look into it.... Hmmm

 

Air in the cooling system will cause fluctuations like those seen by your gauge.

It's dealerships like that, that give all the others a bad name.