Motor that overheats. I've replaced the radiator

Tiny
MMENTJES
  • MEMBER
  • 1994 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 233,000 MILES
I have a 1994 chevy 1500 pickup - 350 motor that overheats. I've replaced the radiator (was leaking), water pump, thermostat and fan clutch. The motor only overheats after the operating temperature has been reached then you accelerate to 55 mph. When the overheating starts the heater starts to blow cool air into the cab. I also replaced the temperature gauge with an after market, to watch the thermostat (180 degree thermostat). What else needs to be replaced?
Tuesday, December 21st, 2010 AT 2:45 PM

3 Replies

Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
This is a classic sign of a blown head gasket to confirm the issue please follow this guide.

https://www.2carpros.com/articles/head-gasket-blown-test

Please run down this guide and report back

Cheers
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Tuesday, June 1st, 2021 AT 6:16 PM
Tiny
MMENTJES
  • MEMBER
  • 2 POSTS
The temp climbs to over 250 and fills the overflow bottle, then flows out the top of the overflow bottle on to the exhaust.

I also believe that the head gasket maybe blown. I've dropped it off at a local mechanic to verify and you are right the head gaskets are blown he will replace them for $850.00

Thanks for your help I love this site.
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Tuesday, June 1st, 2021 AT 6:16 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
Good to hear, please use 2CarPros anytime we are here to help.

Cheers
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Tuesday, June 1st, 2021 AT 6:16 PM

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