My truck is constantly overheating

1995 GMC SIERRA
427,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
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CHARLES RODGERS
  • MEMBER
  • 1 POST
I can't figure out why. I have replaced the thermostat, water pump, and hoses. I tore down the motor and flushed it out I have also flushed out the radiator, put some stop leak and it still overheats. Can you help me?
Feb 24, 2020 at 1:07 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Good afternoon,

First, the stop leak was a very bad idea. It does nothing but clogs up the radiator and heater core.

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Did you change the thermostat? What temp did you use when you changed t?

I would also do a leak down test to be sure a head gasket is not leaking compression into the cooling system super heating the coolant.

https://www.2carpros.com/articles/how-to-test-engine-compression

Roy
Feb 24, 2020 at 8:04 AM
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