93 2.2 camry overheating
 

It overheated so I changed thermostat and flushed it out. It was a cheap thermostat though. When we finished that we were letting it run and checking for leaks and there was no flow and it overheated again. I figured it was a bad water pump. Changed the water pump and timing belt put it all back together. 50/50 mix elevated in front to fill went for 5 min drive. Heat worked, temp guage went up a little past half way and coolant was going past cap to overflow and was overheating again. The fans come on when you turn AC on. No flow, fans have not come on without AC on, no leaks. new thermostat, new water pump, no smoke, no bubbles, no coolant in oil. Any advise would be great.
Bryan

When does the engine overheat? At idle, driving, hwy speeds. Typically the fans only need come on when the engine has prolonged idling or in stop and go traffic. At higher speeds the airflow through the radiator is adequate.

The engine should be able to idle without overheating. The fans will cycle on and off.

There is a temp switch on the lower part of the radiator. The switch turns on the fan if the coolant temp raises about 199F. The location is on the engine side of the radiator, bottom radiator tank. Unplug the harness to the switch then turn on ign switch. Fan should run. If not there is a problem with the switch or the fan circuit.

Have you checked for a plugged radiator? You should be able to hook up a garden hose at full flow to one of the large radiator openings and have the water come out the other without backing up.

Check bottom radiator hose, on rare occasions it can collapse inside.

Is the pressure cap OK?

The other issue is a blow head gasket. How hot did the engine get when it first overheated?

Thanks Joey!
The cap is old. We are going to buy a new one and a new thermostat from Toyota. We did not pull power supply from bottom of radiator to see if it came on. We will do that also. I don't know if radiator is plugged or not but when we get some more fundage we will just buy another one from the local parts store. It does overheat sitting, driving city and driving highway. We will also check lower hose although I didn't notice it being colapsed but will observe during next test session. I'll keep y'all posted. I don't get paid until friday so it won't be until then. Thanks so much for your input. I at least have a plan of action now. Still a bummer though.

My friend and I had this same problem during our spring break on the way back from Panama City to Atlanta and it the problem ended up being a hydraulic lock, with air being trapped in the cooling system.

We thought it was the fans so we bypassed the switch so it would stay on, we thought it was the thermostat so we took it out.

And after all of that it still would over heat it when you started to drive it weather it was on the highway or city after 5- 10 mins of driving.

So we was pulled over again and I noticed the upper radiator hose was really fat, filled with compressed air, after the car cooled it went back to its normal size, so we finnaly made it to a rest stop and we took off the upper rad. hose from the block, and connected the garden hose from the rest stop to where the lower rad hose connects to the block and turned the water on at full force basically flushing the system with a strong force of water hoping to get all of the air out.

We let it run through for about 5-10 mins, and reconnected the upper and lower rad hoses, and started it up and drove all the way back to Atlanta and the problem was solved.