S8 Temperature Gauge - How Hot?
 

Hello all -

Just purchased a 2001 S8 with low miles and drove it home about 3 hours.

During that time, the temperature gauge didn't move or barely moved. I realize the car has a big radiator and it's wintertime in the midwest, but is this normal? I am used to cars that start at low heat and then move to the middle of the gauge and stay there during operation.

The car isn't overheating and the system check ran ok. I know this gauge is a basic gauge, but having it pegged at the bottom doesn't seem normal.

What do other S8 owners find?

Thanks,

Corby

Re: S8 Temperature Gauge - How Hot?
 

I saw that the S8 the working temp is not in the middle.
If the gauge didn;t move at all or barely is either bad temp sensor or termostat.
If you have VAG you can check the temp.

I believe is the termostat I had same problem with my A4

It should be here.
 

<center><img src="http://pictureposter.audiworld.com/80919/dsc02553.jpg"></center><p>

Also check here. Unlocking the Secrets within the Climate Control Panel (M.Y. 2000 up)
 

<ul><li><a href="https://www.audiworld.com/tech/int.html">https://www.audiworld.com/tech/int.html</a</li></ul>

Check the temperature with the un-documented digital guage.
 

Press and hold the recirc button, and then press the vent control up arrow. The left temp indicator then displays a code number (pre-facelift in parantheses), and the right temp indicator it's value. Page up or down thru the codes with the temp + or - buttons.

16 = an air flap position (fresh air versus recirc?)
33 = speed km/h
36 and 37 = voltage
59 = rpm/10
102 (98) = coolant temp oC, as read by the instrument cluster
103 = internal cabin temp
104 = HVAC outlet air temp

It's been quite a while since I've checked the coolant temp, but IIRC, the temperature should be running ~90 oC winter or summer.

So if thermostat is bad - it should be running hotter than normal - 90 deg. or just no temp. report?

Thanks for the help all!

That tells you what the instrument cluster sees. The ECM has its own sensor element.
 

I've had the gauge/HVAC sensor go bad so that it would read cold, or drop back to cold. A $9 part at the dealer.

If it reads cold but the top right side (hose side) of the radiator is warm, then suspect this sensor.

Tom

That's not A8 relevant. Refers to 7-segment digits, wrong channels, etc.

Re: So if thermostat is bad - it should be running hotter than normal
 

If the termostat is stuck open, is going to run cooler then normal, since no matter what is the temp of the water it will go thru the radiator.
If is stuck close, you going to overheated really fast.
I believe the problem u have is ur termostat is stuck open and your car doesn't get in normal working temp