Hey everybody.
I've got a strange one. My 2005 Buick Lesabre busted the radiator and heater core at the same time. The radiator was 2 years old and the HC was very old. It seems as if something happened that broke both at the same time. I'm assuming a sudden over pressure in the system. I replaced the radiator and by passed the heater core and I don't see bubbles coming from the fill opening of the radiator. Is a blown head gasket enough to bust both the radiator and heater core at the same time, or is there another possibility?

Any help is appreciated.

Weird coincidence.

I'd bet the pressure cap got stuck.

It'* a real possibility. I did a test with a cylinder block tester and the fluid went from blue to yellow so there is some leakage somewhere in the engine, but I don't have water in the oil pan yet. I also pulled the water pump to make sure all the fins were still intact and they were. So I'm going to replace the water pump, thermostat, and radiator cap, since I've got to replace the radiator and heater core anyway. I'll probably have milkshake oil next week, but maybe it will last a little while longer so I can decide whether to fix it or sell it.

Thanks!

Throw a can of bars leak or head gasket sealant. Some of these will get you a fair amount of time.