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What’s causing over...
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What’s causing overheating?


Topic starter

son's 2007 Chevy Express 2500 Basic Model, 287K miles, automatic



His vehicle leaked coolant for quite a few months and he would add new coolant every few days. When he realized that he wasn't going to be able to fix the problem right away he started using water from his garden hose. THIS WENT ON FOR MONTHS BEFORE HE WAS ABLE TO GET THE NEW PARTS AND DEDICATE ENOUGH TIME TO THE REPAIR.

He has replaced a leaky water pump, thermostat, radiator and hoses. He also has flushed the system two times with the strongest flush Autozone sells and now it flushes clean water. He only gets about 1 1/2 miles before the temp gauge sounds the alarm and he pulls over and waits 15-20 minutes. He also noted that turning the heater to max hot and the fan to max high only blows cold air.  The heater had been working fine prior to the R&R he did. 

Hope you have some insights to help us.


 Philip Boettger ...I don't know what tags are...

1 Answer

He did not properly bleed the air from the cooling system or replace the radiator cap, probably.  Also, check for proper function of the coolant temperature sensor.  No coolant flow through the heater core.