Overheating Solara

My 2001 Toyota Camry Solara is a salvage car that has 139,000 on it and when I recently had the timing belt replaced I had the water pump replaced to play it safe. After that the needle on the temp guage would soar up into the red but then the machanic finally got it come down and stay down. Then it did it again on a very very hot 112 degrees day and I did nothing but have a friend re-fill up the radiator and the temp guage has gone up to the middle of the range and stayed there on every drive. Suddenly now, in much cooler weather, it started going up to the red again. So I filled the radiator which didn’t take much, but that’s not solving it. What should I do?

I’m sure that after many over heating episodes you likely need new head gaskets at this point. Not sure if the work done had anything to do with the overheating. The only way the water pump change could have caused overheating is if it leaked and you ran low on coolant. Every time the needle goes into the red it is causing damage to your engine, so don’t let it.

It sounds like your mechanic didn’t get all the air out of the system after replacing the water pump. The heating/cooling cycles eventually get the air out, but not without the possibility of engine damage as Xebadaih suggests. There is a simple test that can be done to see if combustion gases are getting into the coolant, which indicates head gasket failure. Any reputable shop should have something similar to this: http://www.amazon.com/UVIEW-560000-Combustion-Leak-Tester/dp/B000NPDL76

There is another possibility: during hot weather when you weren’t using the heater, the temperature cycles worked the air out of the main loop of the engine cooling system but any trapped air in the heater core would have been trapped there since the heat wasn’t switched on. You noticed the low coolant level and topped up the system and your overheating problem went away. Now during cold weather, you have turned on the heater and any air that was trapped in the heater core has now migrated into the main cooling loop, causing the original problem to return. This possibility depends on the design of the heating system, as some cars use a coolant valve to shut off the flow to the heater core while others just let the coolant flow through the core all the time and manage the heat output with the “blend doors” inside the vehicle.

You didn’t say whether you have the I-4 or V-6 Solara, but that information would be helpful.

Thanks so much. I have the 4 cylinder Solara. I think you diagnosed correctly as the problem had gone away for months and then returned after I first used the heater when cold weather came. Now I understand why I once read that you have to have the heater turned all the way on when filling or bleading the collant. Sounds like all I need to do is get a shop to properly fill and bleed the system? Or can I just fill it myself and fill up the overflow holder and do it all while the engine is running with the heater turned on all the way. Any specific instruction you have for me?