Temperature gauge stops working occasionally

BENJIDUB

MEMBER
2008 CHEVROLET TRAILBLAZER
4.2L
V6
2WD
AUTOMATIC
151,000 MILES

Sometimes my temperature gauge randomly stops working. The car doesn't seem to overheat when it does, no smells or visible leaking coolant. Also, the heat only works on the passenger side, I don't think the back heater even turns on, and the driver side blows out cold air. I haven't tried the A/C so I don't know if it even works.

Sunday, March 28th, 2021 AT 5:48 AM

5 Replies

KASEKENNY

MECHANIC
18,907 POSTS

More then likely this is the coolant temperature sensor is beginning to fail. What happens is when this begins to fail it can act erratically or just stop reading all together.

I attached the process below on how to replace it which is what I would do in this situation.

However, if this is not happening all the time then you may want to wait until it acts up again to test it. When it does, we need to check the voltage on the sensor to find out if it is operating. I suspect you will find 0 volts which would indicate the sensor is not operating.

Let us know if you have questions on this. Thanks

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Monday, March 29th, 2021 AT 6:29 PM

BENJIDUB

MEMBER
3 POSTS

Should I also replace the thermostat at the same time?

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Tuesday, March 30th, 2021 AT 8:50 AM

KASEKENNY

MECHANIC
18,907 POSTS

Only if you want to however, I see no reason to unless the vehicle is overheating. The heater not blowing on the one side, I don't think is related to the gauge.

So it is key to make sure the coolant is full and then change that sensor and retest everything. Normally these things are no a thermostat issue but if you are there and want to change now then that is not a bad thing.

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Wednesday, March 31st, 2021 AT 6:08 PM

BENJIDUB