Thread: L36 Overheating

2003 Monte SS with 140k

Hit the danger zone on the temp gauge today, got it home and checked it out. Definitely blew the t-stat gasket. Bout 2 weeks ago it overheated on me, all the gaskets were fine but i had boiled off most of my coolant, oil was clean and i tore down to the LIM and didnt see any stray coolant, at that time i replaced the T-stat and flushed the coolant. For the past few months I've had issues with the coolant boiling off, even after a 10 min drive to taco bell, when i stop i can hear the coolant in the over flow boiling.

In spring of 2010 I replaced the water pump, LIM gasket, t-stat, and radiator fans. All of which are holding up fine. I know theres a bigger issue causing this but I cant figure it out.

Any suggestions?

Upper intake manifold cracked?

water pump? correct chemistry of the coolant? purged the coolant system at the thermostat housing? enough coolant in the system?

Originally Posted by QUICKSILVER462

The radiator cap is directly responsible at keeping pressure raising the boiling point. You have not stated that you inspected or replaced it.

That I havent and ti completely slipped my mind, that will probably be the next thing i try.

UIM is solid, with a new gasket and no visible leaks. When the coolant was last touched i did a thorough flush, and got it topped off. I'm not sure of the warranty the new water pump came with, but the gasket is fine and its not making any odd noises so I'll assume its fine for now, although i may come back to it.

Radiator cap was bad, I feel stupid lol. Atleast it was a cheap fix.