2009 granturismo s - coolant temp gauge seems too high, even from cold

[Boris-JHB]

Friends,

Quick question:

On my 09 GTS, I occasionally get an excessively high temp read on the coolant. Normally it sits steady at 90 degrees Celsius. Now and again, the gauge already sits at 80 or so without my having even started the car. I live in South Africa and it is just getting warm in the mornings. I can feel the coolant being max 20 degrees but the gauge shows 80. If I drive now, the gauge will rise proportionally with the engine heating up. But the gauge will reach into the red, without actual over heating. I think the thermostat might be stuck open but I am not sure. The fan seems to be working and we are not dealing with actual overheating. Any thoughts on quick things I can do to "reset" the temp gauge or check the thermostat without taking the car in? Last night I had 120 degrees reading but the coolant was merely warm not steaming ...

Thanks everyone!! Your thoughts are much appreciated.

 

[CatmanV2]

Sounds more like a sensor than the thermostat to me. As long as you're measuring the temp as OK you should have no immediate issues.

If the stat was stuck open, you'd have issues getting up to temperature on a long cruise, although that may be unlikely in SA. You can check to an extent by feeling the inout and output hoses after you start the car. The input should be come noticeably warmer before the stat opens and the temperature evens out.

C

 

[conaero]

If the guage reads 80 with the engine off I would say it's the guage that has failed.

Next time it does this bang the top of the dash.

 

[bigbob]

If the guage reads 80 with the engine off I would say it's the guage that has failed.

Next time it does this bang the top of the dash.

Agee with this. I was in Joburg a few weeks ago and everyone told me how cold it could get overnight in the winter and they are right! Saw no Masers but loads of BMWs.

 

[beau]

Mine does this occasionally, turning ignition on and off a few times fixes it, gauge / needle thing gets stuck

 

[Boris-JHB]

Thanks, everyone. It was the gauge, indeed. Fist-bumped the dash and switched ignition a few times. Then the gauge rolled right back down again.
All the best!
B

 

[conaero]

Thanks, everyone. It was the gauge, indeed. Fist-bumped the dash and switched ignition a few times. Then the gauge rolled right back down again.
All the best!
B

 

[beau]

I find hitting it doesn't do anything, only flicking ignition on and off a few times seems to reset it somehow, it happened to me again yesterday, done it about 5 times in the past month, not gonna bother fixing it, as probably need a whole new cluster!