Hello guys I'm new to the Lexus make and I just purchased my first GS430 about a week ago. The car came from California and is new to the Arizona summer. One day driving I noticed it was steaming from the engine bay and that the needle was well above the "H". I parked the car and changed the thermo, Cooling fan switch, and radiator cap only to notice small horizontal cracks on the top of the radiator. Assuming that a failure somewhere else caused stress fractures on the radiator due to high pressure. Is that the culprit of the overheating problem or could it be the radiator along with something else? The fans do come on but turn off after about 30 seconds of running even if the car is above half temp and there is pressure being released from the fractures.

 

you answered your own ? here i feel

change the radiator and then recheck everything

 

The plastic tops will eventually crack with age. Either plan on replacing them occasionally or spend the extra for an all aluminum model.

 

Thanks, i just wanted any insight as to if it was caused by a failure elsewhere.

 

Just replaced mine not too long ago. The dealer put in the new Toyota pink antifreeze (I guess it's better?) at any rate it's just something that goes after 200,000 miles.