On my way home in about 30 minute trip which I was a third of the way into my serpentine belt popped off. This meant there was no cooling in the engine block and the coolant started to boil but my engine temperature gauge did not make the red zone. RedZone is 260°, but my coolant nevertheless boiled. I could hear the bubbling action. I have dexcool with OAT reddish orange substance. I thought it boiled at a higher temperature. Have I weakened the head gasket and is there anything I can do to keep it from failing anytime soon?
Yes it not good for the engine and it could have weaken it.
But I would check if the oil has gone a milky brown or your coolant has gone a milky brown colour.
Never used it but scotty has some video on head gasket fix with fluids.
The engine has hot parts and not so hot parts. When the belt came off the coolant stopped circulating. The coolant in the hot parts started boiling, and the coolant next to the sensor didn't. Or maybe there wasn't any coolant on the sensor at all.
Antifreeze does not change the boiling point significantly. That's why they don't call it antiboil. The main mechanism that suppresses boiling in a car is pressure. The radiator cap is designed to hold around 15 PSI which raises the boiling point to around 270F.
Did it start venting? Was steam shooting out of the radiator? If no, then you're probably fine.
If yes, then unfortunately the engine is compromised. At any moment it could hydrolock and puke out some connecting rods. It would need a top end rebuild.
@mountainmanjoe
Ok thanks. I never saw steam so maybe just try the seal repair idea Scotty shows in his video on head gasket repair.
I wouldn't use those products unless I knew I had a leak