magneti

runs cold if its not 100 degrees here until the engine gets semi hot then its just semi-cool.

when its 100 degrees its never all that cold either way.

zak456

Did you ever figure out yor problem? Im having the same issue.

lexforlife

iTrader: (7)

has anyone checked bad ac condenser if bad or clogged condenser it will make your rad get super hot with ac on

Chackochan

I have a different experience with my 1993 ls400 with 210000 miles. Car runs fine and has no over heating most of the time. But some times the a/c airflows goes automatically from internal circulation to external and smell gas inside. If I press the button again to make the outside air flow to internal circulation, the car starts over heating. What I do is to switch of the a/c for 5 minutes and turn it on and it works.
Outside temperature is 45 degree C.


Can any experienced hands in this Lexus Forum give me an advise in this case.


Thanks,


Shyju

aj007

Yeah, I too am having the exact same problem with my GS 430. I'm guessing it was his radiator since that's what he was about to replace before going silent.

Chackochan

Over Heating is very complex and very difficult to know the cause. If car over heats when a/c is on indicates that cooling system works and is weak where with excess heat, it cannot survive.
Start with: Cooling fans (3) T-stat, Air in the system, Radiator or hoses' leaks, Water pump, clogged radiator and finally Head gasket.