Kanvis78

I have a 2000 ES300 that has started overheating at idle or stop and go traffic. Fine when actually diving. The fans run and go to high speed, but only for about 5 seconds then go back to slow speed. Not sure how to check the thermostat and water pump operation, but I would assume they are OK because temp is perfect during long drives. While idling, if I squeeze the per and lower radiator hoses, it doesn't feel like any water flow in either. Not sure where to start and it's our only transportation. Please help ! Thanks!

PFB

One area you should check is for a partially blocked radiator, or dirty cooling fins.

Kanvis78

How can you checked for blockage ? I did hose of fins from inside to clean.

JDMSteven

If its been a while, or you need to change your fluid anyway, drain the coolant and grab some radiator flush.

EricMac

If no additives have been added to the system ( system stop leak etc. ) you should Not have blockage. After checking fluid levels etc. Make sure your fans are cycling on and off. You should be able to do this by simply starting vehicle. Fans should cycle after aprox. 5 min of idle time. If they do not turn on and temp gets to 3/4 to hot range. turn off engine and test the fan relay. Fans aid in cooling esp during stop & go traffic. Also to be sure the thermostat is opening, while engine is warmed up check that your upper and lower radiator hoses are approximately the same temp. ( X be careful when doing this with engine hot HOSES CAN BURN YOUR HANDS X ) If one hose is significantly cooler than the other you may have a blocked thermostat restricting your flow. Good Luck