Temp Gauge coming down while driving (Camry 2007 2.4L) (Thermostat replaced)

Hello there,
I hope you all are doing well.

I’ve just bought a used Toyota Camry 2007 (V4_2.4L) and I noticed that while I am driving the temp gauge starts going down, giving an indication of the engine not being fixed in the correct operating temperature and once I stop, the temp gauge starts going up and reaches the correct operating temperature (a bit lower than the middle).

I assumed that it would be due to a faulty thermostat that stays open and does not let the engine to stay warm while driving, then I replaced the thermostat but it didn’t help and the problem still persists.

I am writing to ask if any of you have encountered the same problem and may provide me with probable fixes for it.


Your diagnosis seems correct. Cooling while driving indicates a stuck open thermostat.

I’d suggest either you installed the t-stat backwards or you got a bad one right out of the box. Both happen.

I would also look at the coolant temp sensor data with a scanner before changing any more parts.
It’s possible the actual temp is not falling and it’s an issue with the gauge.


Make sure the radiator cooling fan(s) aren’t operating while the car is being driven down the road.


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