1990 thermostat replacement

[mrjiggles]

Replaced radiator in 1990 camry. All was working well. Decided to replace original thermostat with toyota replacement thermostat.
Now engine overheats after a few minutes of idling. Any ideas? Thanks.

[fourdrinie]

either it's defective, which you can test in an almost boiling pot of water to see if it opens...or you placed it in backwards....guess you have some testing to do...

[Doctor J]

Is it 4 or 6 cylinder?

[mrjiggles]

It's a 4 cyl. I tested the new toyota thermostat in boiling water and it opens. So does the original thermostat. I put back the original thermostat and the car doesn't overheat, however it is running slightly hotter now. Temp gauge needle is not in the 12 o'clock position as it used to be. It's pointing about 1 o'clock. The cooling fans are working properly as well. I've seen discussions about burping the engine. Could air be a possible cause? The coolant level is full and it's new. Thanks for the responses.

[Mike Gerber]

"Temp gauge needle is not in the 12 o'clock position as it used to be. It's pointing about 1 o'clock. The cooling fans are working properly as well. I've seen discussions about burping the engine. Could air be a possible cause?"

Yes it could. Did you properly bleed the system after installing the new thermostat? If not, park the car slightly uphill. A slightly slanted driveway will be enough of an incline. Remove the radiator cap. Turn the temperature indicator to hot and place the other lever in the defrost mode. Now let the car idle like that for 45 minutes to 1 hour. Note the bubbles rising from the radiator neck.

Also make sure you installed the thermostat with the bleed hole near the 12:00 o'clock position. 11:00 o'clock to 1:00 o'clock is acceptable.

Mike

[mrjiggles]

Thanks Mike. I will bleed the system as you stated. Thanks again.

[greg r]

thermostat with the bleed hole near the 12:00 o'clock

That's a very important detail I'm sure some folks miss. At least I've never trapped air while remembering that position.