cosmoatman

Just wanted to add my experience in case anyone was still dealing with this problem. I had a similar issue with boiling coolant. I was trying to burp the system after changing my radiator and radiator hoses. I would turn the heater all the way up, burp the system for 30ish minutes, but when I would shut off the engine at the end, the coolant would boil over and erupt, even if I used a large funnel that was attached to the radiator cap to prevent leaks. I realized that my electric fan wasn't coming on, though, so once I replaced that the issue went away, and I was able to burp the system normally. I think the coolant was actually boiling in the system the whole time, but with the engine running and the water pump working, the coolant was flowing through smoothly and not boiling over until I turned off the engine.

TrailerTrash