New symptom since I changed timing belt and WP last month - boiling noise in the area of the front of the engine and into the overflow bottle for just a few minutes after shutting off the engine.

No overheating at all - gauge is rock steady in the center and I've put about 3K miles on it since the new WP - including four straight days of 8hr plus stints at up to 80mph in 100+ degree weather. No leaks or escaping steam.

Searching other threads I believe I either didn't fully fill the system or got the mix wrong. The level in the radiator is always at the top and I'm pretty sure I was close to 50/50 in the coolant mix. Did I miss a step in bleeding air out of the system when refilling the radiator? Would a worn radiator cap cause this?

Any thoughts or ideas would be appreciated.

Thanks,

Ron

 

theyre a bitch to fully burp. You need to use a coolant funnel, and let the car run for over 30 minutes, varying the speed occasionally. It helps to raise the front of the truck, too.

 

Thanks Mb, I'll give that a try.

Ron

 

turn the heater on too, air pockets can get traped in the heater core

 

Thanks for the advice. As often happens, it turned out to be the most obvious cause. A new $7 radiator cap cured the boiling. I guess after 10 years the original seals gave up the ghost. Especially after I let them dry out for a week while I replaced the TB and water pump.

Ron