Engine still getting hot after replacing thermostat and water pump

Tiny
EDDIELANDDD
  • MEMBER
  • 2011 CHEVROLET MALIBU
  • V6
  • 2WD
  • AUTOMATIC
  • 97,000 MILES
So my dad replaced the thermostat and water pump with OEM parts. So when I drive the car temperature stays below half. But if I idle for a while the temperature will raise 2 ticks above half and the cooling fan Kicks on and goes back to normal. But this happens every time I drive. Does anyone have a thought to what’s wrong?
Wednesday, June 10th, 2020 AT 5:06 AM

7 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good morning,

It sounds like the coolant temperature sensor may not be sending the correct signal to the ECM for turning on the fan.

I would start by replacing the sensor and see if it comes on sooner. It should come on at 208 degrees.

What temp thermostat did you install?

Roy
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Wednesday, June 10th, 2020 AT 5:25 AM
Tiny
EDDIELANDDD
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  • 4 POSTS
Yes, that sensor was also changed my father got the parts from GM directly.
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Wednesday, June 10th, 2020 AT 5:30 AM
Tiny
ASEMASTER6371
  • MECHANIC
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Okay, what temperature thermostat was replaced?

Roy
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Wednesday, June 10th, 2020 AT 5:35 AM
Tiny
EDDIELANDDD
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  • 4 POSTS
All parts are Ac Delco and the thermostat and housing was changed.
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Wednesday, June 10th, 2020 AT 5:41 AM
Tiny
ASEMASTER6371
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Okay, I need the temperature of the thermostat. The reason I ask is if there was a lower temperature thermostat installed, it would explain the difference in the gauge reading on the dash. If there was a 195 degree installed, then there would be only a small movement until the fan came on.

If there was a 180 installed, then there will be more movement until the fan came on.

Roy
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Wednesday, June 10th, 2020 AT 6:38 AM
Tiny
EDDIELANDDD
  • MEMBER
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Yes, the thermostat is a 195.
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Friday, June 12th, 2020 AT 1:06 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Okay, make sure there is no air in the system.

If all that is good, it looks to be the gauge itself in the dash.

The thermostat will keep the engine temperature at 200 degrees and the fan will kick on at 208. There should be next to no fluctuation of the gauge.

To be honest, I do not think you have an issue at all that needs attention.

Roy
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Friday, June 12th, 2020 AT 1:19 PM

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