PT Cruiser Overheating Question

PT Cruiser
Year 2002.

Replaced thermostat about 2 weeks ago, after pegging the hot side. Now-it
runs cool on the open road, between the first mark and second.

In town, while sitting in traffic-it starts to peg to the hot side again.
then back on the road-it runs cool. tells me the thermostat is ok.

So-does this baby with 136k have a sensor that's gone bad or is it the
fan....Also-there's no fluid on the ground when it overheats, so it's not a
freeze plug. FYI.

Thanks in advance and have a safe July 4!!

 

Check the fans and make sure they are working. It could also be the water
pump even though it is not leaking. I experience my truck overheating with
no leakage but the impellors wore so worn down the pump was not sufficient
for the heat Louisiana. You may also might want to check and make sure you
have no air in the system.

 

From what you describe (overheating when at idle in traffic, cool at
Interstate speed), I'd suspect the fan is not coming on when it should.
Could be the fan, the relay, the coolant temp sensor (some vehicles have
more than one sensor), or the wiring between them. Good luck!

Bob