Hi all, 

My girlfriend's got an 03 Audi TT. It seems to run at > 90C when in normal operation and we've noticed recently that it'll occasionally dip into the red before dropping back to where it sits in the image. In any other car I've driven the temp would sit in the middle, in this case 90C, but her Audi always seems to sit on the mark between 90 & the red. Does this need checking out or is this normal?

I'm also not sure how worried to be about it dipping into the red, the coolant levels seem fine.

Thanks.

IMG_6549.HEIC

Hi Simon, far from expert commentary from me, similar to you I have never had such variation in a 'normal' running car. Maybe this thread from the TT Forum is of use ? 

https://www.ttforum.co.uk/forum/viewtopic.php?f=2&t=243227

That's very useful - thank you! We'll try the temp sensor first as it seems it'll either be the temp sensor or the water pump.

Hello Simon,

One could be excused for thinking this could be a thermostat problem, but it first needs to be establish what the actual/dynamic running temperature is, to eliminate a possible faulty temperature sender. 

You could ‘simply’ change the thermostat ( in my book only using a genuine VAG part) - or get it changed anyway. This may solve the problem and will save diagnostic costs, but a gamble it will be. 

Kind regards,

Gareth. 

Thanks Gareth. I've got a friend who works for Audi in Oxford so it's going to him on Friday.