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Sparky
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Discussion Starter #1 (Edited)
Hey All,

Been having an intermittent issue with the coolant temperature gauge reading 0, even tho the car is warmed up, and the cooling fans running on high. This seems to happen at random times (the car will start up and everything works fine, then half way through a trip the gauge drops to 0 and fans kick in). The issue will go away and the gauge will work (sometimes the same day or a few days later). CEL only comes on sometimes (the other day i drove 3.5 hours with a 0 gauge reading and fans running high with no CEL) but when it does come on it clears with a battery reset. Sometimes ill go weeks without an issue but over the passed few days its been happening more frequently.

Coolant levels are perfect, and I have changed the coolant temp sensor.

I have read on other posts that some are claiming that changing the thermostat fixed their problem and I think I will do this next.

My question is, if it is the t-stat why is the gauge reading 0 and wouldnt there be no heat in the cabin because i seem to have heat while driving?

Any help is appreciated, and as i mentioned ive read other posts on this and there seems to be no conclusive solution even tho we all have the exact same symptoms.

EDIT - forgot to mention it's 06 2.4L

- Aaron
 

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Most report that the thermostat is the problem but it could also be an intermittent in the ECT sensor harness or connector. The code will likely tell the story.
 

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Sparky
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Discussion Starter #5
Most report that the thermostat is the problem but it could also be an intermittent in the ECT sensor harness or connector. The code will likely tell the story.
Ya i was originally thinking loose connection somewhere too. I did a battery reset 2 days ago and the issue hasnt come back yet (no cel, gauge works, and cooling fans not running full blast). It does seem that the car takes a very long time to reach its normal running temp tho but it gradually does. Make me think the tstat is intermittently sticking, if that makes any sense?
 

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Varsity Squad
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I don't remember the code I had, but it was for "over cooling", the thermostat being stuck open. When I pulled my t-stat it wasn't actually stuck open but an o-ring that went around the "plunger" portion was torn and allowing coolant to flow through. If your 6 is taking a long time to warm up I would say this is the problem, but you are always best to find out what the codes are before you go "throwing" parts at it.
 

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Ya i was originally thinking loose connection somewhere too. I did a battery reset 2 days ago and the issue hasnt come back yet (no cel, gauge works, and cooling fans not running full blast). It does seem that the car takes a very long time to reach its normal running temp tho but it gradually does. Make me think the tstat is intermittently sticking, if that makes any sense?
Considering your thermostat likely is 5 years old, I would just replace it. They're cheap enough.
 

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I have a 2008 G6 GT 3.9 that has started to do the same thing. No lights yet. But I drove it for 2 hours the other day with the gauge not registering at all. What did you find out ?
 

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Sparky
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Discussion Starter #10 (Edited)
I have a 2008 G6 GT 3.9 that has started to do the same thing. No lights yet. But I drove it for 2 hours the other day with the gauge not registering at all. What did you find out ?
I wasn't getting cel everytime either.

My issue hasnt come back since the last battery reset. Havent got around to changing the tstat yet either tho (which im 90% sure needs to be replaced because my the engine takes forvever to warm up) Ive been driving for over a month and I use the car every day and no issue since. Weird or what

I would try replacing the coolant temp sensor first tho, cheap and easy to do...everywhere ive read about this issue, it seems either the coolant temp sensor or tstat is causing the problem...
 

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I have a 2009 G6 3.6L V6 and mine also is experiencing the same problems yours is. It works from time to time, sometimes it will work on start then turn off mid-drive. other times it doesn't read on start but will kick on mid-drive. If it stays off for a long period of time the engine light will come on and even sometimes it will start working again and the engine light will TURN ITSELF OFF. However if I clear the code manually the gauge will kick on immediately. I have actually got the code from this and it is saying the thermostat is not reaching recommended running temperature. which supports the slow to heat to normal running temp. It will raise slow and almost stop right before the point of running temp.

This COULD be caused by the seal being broken(this is caused more in the north that experience snow) and allowing excess coolant into the system. Just replace the thermostat.

However it might be a good idea to check the temperature sensor to the engine block because that has had a bad problem misreading over the years. I have still not pinpointed the true cause of this as it could be something with the wire harness and have not gone that far.


I hope this was helpful.
 

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Sparky
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Discussion Starter #12
I neglected to update this thread.

The issue was the tstat. The rubber gasket came loose and wasn't allowing the stat to fully close. New stat did the trick 100%.
 
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