car over heating warning

[shamus_mcd]

Guys out and about today in my 3.0Tdi and got a red thermometer appear and a warning to stop car asap.
It then disappeared and returned about 10 mins later and again disappeared but this was as I was pulling into the house.
I popped bonnet and no bubbling not water loss and no over heating of the car either it was sitting at mid point 90.

Could it be a sensor?

[AS6]

It sounds like faulty thermostat my thermostat messed up in my old 2010 S4, if I remember correctly that's the same warning i got it would come and go but took it to the dealer and got a new thermostat installed and everything was good.

Cheers
AS6

[shamus_mcd]

Car has just got 49k miles on it and if thermostast stuck it would either be cold or red hot.
Car drove another 10 miles or so before stopping and no sign of either.
I have reset all codes on the car as it has some historic codes on there but nothing that looks like coolant issue?

[jrsAudiA6]

Your issue might be a temp sensor issue. If understand your post you got an overheat warning but your temp gauge was indicating a temp of 90 deg C. If this is correct than I do not think you have a thermostat issue. My thermostat failed at about 44K miles but in my case I truly overheated as indicated by temp gauge and the subsequent warning like you received. In any case I would have it checked out by the dealer.

[shamus_mcd]

So I had my car out today for a drive and done approx. 40-50 miles.

I also had a wee blast with a little Vauxhaul Astra VXR so engine was well and truly warm.

Good news is no warning and Temp gauge sat at 90deg mid point as per normal.

Finger crossed and will keep an eye on it as all codes have been cleared to see what returns if anything.

If it does I'm thinking it's the sensor.