2001 Lexus GS300 Boiling Coolant, No Heat.

[2001 GS300 luv]

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?

[silverbullitt]

Check your fan & see if its coming on. 

[blackdemon_tt]

It still has air in the system.  You need to detach the coolant reservoir and hook it to the hood with a bungee cord or something.  Refill the tank until it stops draining into the engine, once it's at the full mark. Turn off engine, re attach the tank and restart with heater in full blast to remove excessive air from the system and open the butterfly bleed...  continuously check that it doesnt overheat, if it does, shut it off wait 20 minutes and restart once it returns to sorta operating temp.  Same thing happened to my 02 Celica.  No heat, coolant boils, gurgles and overheats...  not enough coolant to cycle through and it had lots of air...  whole thing took about an hour and a half since it kept overheating, but it's been fine since.