I have this 92 z28 (305tpi). The temperature maintains appropriate levels (when it gets close to 220, the fans come on and it cools back down).

The other day, the top radiator hose blew off. Must have been a lot of pressure. I replaced it and put on a new clamp.

However, when I turn the car off, the coolant reserve compartment starts boiling and antifreeze starts spewing out of the radiator cap. Again, the engine remains below 220 at all times.

I replaced the thermostat and Im going to replace the radiator cap tommorow. My air dam is intact and the fluid has been drained and refilled. I dont see anything wrong with the radiator from the outside either.

Ever heard of this? HELP!!!

 

the problem has to be in the cap, it can't hold pressure in the system. I bet it'll run like a champ when you change the cap.

 

BINGO!!!!!

After reading your reply I went out and got a new cap. I thought that was too simple but it WORKED!

Thanks!!!!!!!!