1999 Camry w/ a problem

My girlfriend has a '99 Camry 4cyl. with quite a few miles. Anyway, her car has a chronic overheating problem. The mechanic changed the thermostat and the water pump, and it still overheats. He also changed the Cat and she thinks he might have messed something up when doing that, but I don't see how that would affect the cooling system. I figure it is the radiator, though it gets hotter at idle. Does anyone have any ideas on what we should do.

One of the more obvious things would be making sure the cooling fans are coming on.
You can check the rad. by taking the cap off when cold,starting the engine and letting it run while observing the coolant in the rad. You should notice when the thermostat opens up by the cycling of the coolant.Replace the cap before shutting down the engine.

oh, just to mention, the fans also work.

how many miles is quite a few, are there any signs of coolant leaks, if not, i have seen head gaskets cause overheating on the 4, cyl, not what you wanted to hear, but a possibility

Thanks, anyone else have any ideas, if it is the headgasket, won't there be coolant in the oil, or visa versa??

If it's a headgasket the symptoms can vary. You may not get oil in the water, but plenty of combustion chamber byproducts, like compressed exploding gas for one. That could also be the result of a cracked waterjacket.

You need to watch for other symptoms too.
1) Cooling system noises
2) Violent bubbling in the radiator.
3) How quickly does it overheat from dead cold.
4) Does running without thermostat help (not recommended on most 4 bangers).
5) Varying engine performance (temperature dependant)


Was there some specific point in time or event when this started happening? How many miles is "quite a few"? (just curious)

Also, check the airflow resistance across the radiator. If the front is pasted with dead grasshoppers it won't cool very well.

quite a few is 100K, i didn't want to list it outright because it is well taken care of and do not want biased opinions that say "well, it's an old car, so"

Might be a bad suction (bottom) hose from the block to the radiator. If it is collapsing internally with suction, will limit coolant flow.

Nah, 100k is nothing, especially if it's well cared for. I know of one Toyota from the 90's that's turned 450k and still passing Calif. smog tests.

Have you checked on some of those obvious things yet?

Thanks a lot, I appreciate it. I have to wait, it's my gf's and she is away at school. Next time she is home I will tackle it. Her mechanic couldn't seem to find the prob, yet I don't know how well he looked, but I will try everything you guys said and post what happens.