hi, can someone help me pleaseeee, I have an 2008 Lexus gs350 awd, I've changed water pump, radiator, and thermostat, the car still over heats, the fans come on, but the car over heats when I drive for an hour or so then stop, please help with any information

 

Have you made sure you removed all the air bubbles in the coolant system? Because if there is a bubble in the coolant it will over heat.

Try jacking up the front of the car and add only toyota pre mixed coolant. By jacking up the front end that will help bubble rise up to the filler. Also coolant cap could be bad, you can take the car to a shop and have them pressurize the coolant system.

Worst case scenario you may have a blown head gasket, over heating the engine will cause this. It maybe best to take the car to the dealer and have them diagnose it before spending money on parts.

 

Yea I've blead the system and no loss of power or signs of head gasket problem, and I also had the radiator cap checked

 

Try taking the car to the dealer or even the toyota dealer and pay for an hours worth of diagnosis. Personaly the more you drive it and let it overheat the more of a risk youre taking of warping the heads and blowing a head gasket

 

Yea your right, thanks for the help

 

How did you bleed the system? May want to try the vacuum bleed method which will also check for leaks. Can be done at home, look up airlift vacuum bleeder

 

Also check if your system is not clogged, sometimes using wrong coolant or mixing coolant with water can make a mess inside the lines. Also check the fans again, maybe the are turning on but not working properly, bad bearing can cause them not to rotate as they should.

 

have you had the fans off make sure they are on right they go in opposite directions its easy to put them on wrong if they are the will be pulling air out of engine bay instead of putting it in
i do believe UK Fans are same spec as US

 

Have you got bubbles in the radiator when you rev the motor, is it using coolant, any condensation coming out the exhaust if so blown head gasket

 

I put the heat on high and leave the radiator cap open to burp the system, over and over again, so I'm kind of sure it's not an air bubble

 

yea i flushed the system, I also checked to see if fans come on and they do, even when car starts over heating they come on

 

Yea I just double checked, the fans are def on correctly

 

i think I might have bubbles coming out of radiator when I rev the engine I will def double check that, and nothing coming out of exhaust

 

Also for some weird reason, I was driving today and the car started over heating when I had the ac on so I turned it off and the temp went back to normal emediately, I checked the radiator and it needed more fluids but nothing is leaking, I'm thinking maybe something is clogged and the engine isn't getting coolant or maybe the head gasket

 

Sounds like your coolant sensor maybe bad or maybe if you go low on coolant your sensor will not get wet to be able to meter the temps.