2001 corolla overheating

[Irwin Daniel]

01 corolla overheating. Changed thermostat (oem Toyota brand) boiled and it opened at 180, waterpump and radiator. Compression check and still overheating. Any suggestions?

[Irwin Daniel]

Pulled the thermostat out and water is now circulating. Can a thermostat that opened when boiled still be bad? Just pulled thermostat out and ran without it. Didn't overheat. Can a thermostat that opened when boiled still be bad?

[Cbatoday]

Are you loosing any coolant from the system?

Is there any oil in the header tank

Have you bled the coolant system to stop air locks

1. Start with engine at ambient temperature 

2. remove the rad or expansion cap

2. Turn the engine on and turn the heat to max. Turning the heat to max allows the radiator fluid to circulate through the cooling system to ensure that all air pockets are eliminated from the system.

3. Rev the engine to 2,000 RPMs and hold for approximately 10 to 15 seconds and repeat two to three times. This will allow the radiator coolant to circulate throughout the whole system and ensure that all air pockets exit the radiator.

 

[Mooly]

Boiling a thermostat doesn't really tell you very much. In normal operation the 'stat' doesn't open by much at all but simply 'hovers' on it's seat opening by little more than the thickness of piece of paper as it regulates the flow. 

[Dread2zz]

On 7/12/2020 at 1:19 AM, Irwin Daniel said:

01 corolla overheating. Changed thermostat (oem Toyota brand) boiled and it opened at 180, waterpump and radiator. Compression check and still overheating. Any suggestions?

Does it drop below the cold start rpm? (1500rpm) when heated up? 

[Irwin Daniel]

No. I pulled thermostat out and it doesn't overheat. Taking oem Toyota thermostat back and try another one. I replaced the thermostat about 6 weeks ago and did fine until a week ago. Just finding the time to get back to it. 

[Zunoon]

I have a Corolla 2001 and started having overheating problems. I changed the radiator and all normal. I have also been advised to replace the hoses, my old ones  look good, but check the stiffness. My old ones are very soft and supple and this could cause them to collapse when the driving thereby restricting coolant flow which causes overheating.