'93 Lexus GS300 is running hot. on 1999 Lexus GS300

Just changed the harmonic balancer, radiator and thermostat, but car starts running hot. Please help.

by in Calumet City, IL on August 29, 2013
2 answers 3 comments
ANSWER by on August 31, 2013
THERE MAY BE A BLEEDER VALVE THAT NEEDS TO BE OPEN IN ORDER TO PURGE AIR FROM THE SYSTEM WHILE FILLING.
COMMENT by on September 20, 2013
Thank you, will have it checked. The mechanic told me that there is a lot of pressure in the motor that causes the water to backup in the reserve box. He suggests that it could be a blown head gasket, which I find hard to believe since the car never ran hot until the harmonic balancer was changed.
ANSWER by on September 20, 2013
check to see if your cooling fans are working
COMMENT by on September 20, 2013
The main radiator fan is working, but not the cooling fan. Don't know how to get it to work. Please advise. Thank you.
COMMENT by on September 24, 2013
The only way I can see a connection between an overheating condition and replacement of the balancer on a GS300 is through the water pump drive belt. I believe the water pump has a separate belt with its own adjustment point and all belts must be loosened in order to replace a balancer. I'm betting the water pump belt is too loose to turn the pump fast enough at higher speeds or possibly any speed. Incidentally, temperature and pressure are directly proportional so as the engine heats up, the pressure will also rise. To address your concern with the cooling fan: at only two times will both fans run simultaneously. One is during overheat and the other is when the A/C is running. Check your belt..