Running Warm

[dybgpn]

Hey guys, I took my 87 truck w/ 22re down to jiffy lube to have the radiator flushed and filled for winter. Before I had that done my temp needle always stayed just below half (ever since I have had my truck, about 1.5 years). Now when I turn the heater/defroster on it rises to above half to about 3/4 to close to red for my taste. when I turn the heater off it goes back down below half. What is going on here?? The radiator is full, and the overflow is at the full level also.
Should I get a new radiator cap? I can compress it with my fingers (off of the radiator) so fluid should be getting to the overflow (when the cap is on).
I don't know very much about radiators.
I don't want my truck to start overheating. Could the pressure thing they use to flush the radiator have done smething to my truck?

[DeadlyPeace]

I'd say take it back to Jiffy Lube and make them fix it. Probably something simple like they didn't fully burp it or didn't run the heater while burping it.

[BuckUrspace]

that sounds aboat right !

[ToyotaMike]

Agree with the above. Also another theory is that when they flushed it it could have cleaned off some of the corrosion on the temp sensor so it's reading a bit more accurately. But definately check the first suggestion before anything else.