So I just picked up a 2.7T a6 and I notice the coolant temperature is sitting a bit high (first tickmark past middle) when i drive. I'm thinking maybe it's a sticking thermostat or bad ECT sensor or that aux fan switch thing.

The weird part happened today though - on my way home i notice the temp is sitting steady at 1 tick past. When I actually arrived at the house, it was back to center. So I decided to see how it reacts and drove the car around the block and i got back to to around 1 tick past. Then I pop the hood, jiggle the coolant hoses and bam it drops back to center. The like 10 mins later I start the car again and it's sitting back to 1 tick past (WTF... it got hotter parked?).

Do you guys have the ECT part number? I'm gonna start with the temp sensor and go from there.

 

Whats the condition of your coolant?

 

It's there.... no idea beyond that

 

I ment is it dark? dirty? stained res. tank usually means dirty coolant.

by the way my A6 does the same thing only with oil temp. And yea it is the 2.7T 6-sp.

 

Yea im gonna bet its the Coolant Temp Sensor $30 at local dealer or $15-25 online. Pretty simple to install also.

 

It's pretty dark and the tank is yellow - I'll do a flush as soon as I plop in the new coolant sensor.

 

Might as well install a new thermostat as well while you're in there and flush the coolant...but yeah it should be the sensor or the thermostat.

Good luck.