2000 Chevy venture van 3.4l still over heating, after replacing thermostat, radiator cap, fans work properly. Checked relays and all seem to work properly. Van Idles fine, then will get to normaol temp. And all coolant will go into overflow tank. Using temp gun on thermostat housing, block, water pump all temperatures seem normal (ie thermostat 180-220, water pump 150-160) not sure what to check next.
Check the radiator if its clogged and also try bleeding the system could be airlock-if okay have it block and pressure tested to find out more what's going on.
April, 27, 2011 AT 11:59 PM
Hey Raz, sounds like he is pumping combustion gases into the cooling system from a cracked aluminum cylinder head or bad head gasket, most likely cracked head, call around and find a shop that does chemical head gasket tests, simple test to tell if there are combustion gases in coolant, it will save alot of time and money(unecesary parts) trying to figure it out.