You want to check for proper coolant flow. First check the water pump to see if its leaking coolant the pump will either be wet at the bottom of it or you may even see coolant on the ground. Could be a bad water pump.
Next pull your oil dipstick out and check the oil for a milkey like substance which would be an indication of blown head or gasket.
Next check to see if the radiator is filled to the rim but of course do this with the engine cold. Then start it up turn the heater on high and let the motor run until it warms up. Once you see the gauge moving pinch the top radiator hose to see if coolant is flowing through the system, but don't let the van over heat. If you have no circulation then 1 of three things or all could be wrong, 1) clogged heater core 2)blockage in the block 3)clogged radiator 4)stock thermostat.
You said the radiator was pressure checked but did your mechanic check the system for blockage or even tried to flush the system.
I hope this helps let me no.
Thursday, February 26th, 2009 AT 5:51 AM