Month and a half ago my wifes 05 Camry 2.4 threw the CEL on. I scanned it a couple days later as no major problems were apparent other than the temp gauge had a reading that was cooler than normal. I forget what the exact code was, but something about the coolant temperature. I checked the temp sensor first and the voltage reading was within spec. Called AutoZone to inquire if they had a thermostat. Anyways, finally got around to changing it yesterday. Replaced the lost coolant and let run for 10-15 mins at idle...all good. The wife calls me this afternoon from road and the temp gauge pegged out after 5 mins of the car running....then just a moment or two later settled back to the normal position. Water pump is just fine....temp sensor is fine....thermo should be fine given thats its new...I'd love a suggestion...


thanks..

 

Hello,
I don't want to be simplistic but did you make sure the thermostat was the right direction, not backwards. Another thing may be you have the wrong temperature thermostat. To check the thermostat action, heat it in some hot water and watch the mechanical action. If it moves in boiling water then it is OK.

 

Haha, I'm not a kid!! Yeah its the correct temp range...180F

And yes, its installed the correct way. Its mechanical action was already tested.