New water pump, thermostat, radiator. Red Asian Coolant. Cleaned out all hoses. Sealed thermostat housing. Flushed system, radiator, back/forward flushed heater core. Burped coolant system multiple times with burping funnel. No milky oil, no white smoke from tailpipes, no obvious gasket leaks around heads. Burping will burp larger air bubbles ever 15 secs after 30-40 mins of revving/idling engine, wont burp air revved up as soon as I let off gas, air bubbles start in 15 sec intervals. Runs perfect on highway, hot air coming from heater, no overheating but when stopped it starts to boil coolant, heater blows cold air and begins to overheat. In traffic, cool to op temp, only lasts for around 20 mins before heater blows cold air and coolant starts boiling in overflow tank. Any help here?
