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nelson mayor Posted on Jan 22, 2014
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Engine hot ac turned off

Top radiator hose hot bottom hose cold temp guage stays on160

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Stephen

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  • GMC Master 21,873 Answers
  • Posted on Jan 22, 2014
Stephen
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Sounds like a thermostat problem.

4 Related Answers

Anonymous

  • 7 Answers
  • Posted on Feb 20, 2010

SOURCE: My 2003 GMAC guages are failing. It started with

gm sent out a letter to 2003 owners if you have cluster sticking gm will replace for free

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woodchuck789

Charles T Nevin

  • 4070 Answers
  • Posted on Mar 24, 2010

SOURCE: all of a sudden I am getting an overheat

Take the thermostat out and put it in a small pot and heat it on the stove top watching to see if it open when it gets hot. If it hasn't opened all the way by the time it boils its bad

emissionwiz

Marvin

  • 85242 Answers
  • Posted on Oct 26, 2010

SOURCE: '08 silverado. dash board diplays, engine running

P0128 OBD-II Trouble Code Technical Description

Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
What does that mean?

This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat. Similar codes: P0125

In determining the engine did not reach a "normal" temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolant temperature (ECT) sensor reading, and the speed of the vehicle.
FB.init("dd7d9e9681341cde77587bc6a2029f6f"); OBD-Codes.com on Facebook Symptoms

You will likely not notice any drivability problems other than the MIL illumination.


Causes

A code P0128 may mean that one or more of the following has happened:

Possible Solutions

Past experience indicates that the most likely solution is to replace the thermostat. However here are some suggestions on troubleshooting and repairing a P0128 OBD-II code:

  • Verify coolant strength & level
  • Verify proper cooling fan operation (check if it's running more than it should). Replace if necessary.
  • Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary.
  • Verify proper intake air temperature (IAT) sensor operation, replace if necessary.
  • If the above items check out good, replace the thermostat


Anonymous

  • 4669 Answers
  • Posted on Nov 04, 2010

SOURCE: no heat top radiator

Have you tried backflushing the heater core?

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