In the three months I've owned my 2001 TT (180 hp) the temperature gauge has stood straight up half way between hot and cold. Two days ago, while spending 30 minutes in excruciating stop and go traffic, rarely leaving first gear, the temperature warning came on and the gauge was almost pegged on the high side (half way between highest tick mark and next highest mark). I pulled over, waited for traffic to subside, and took off in a direction with better traffic flow. The temperature came down quickly to the middle position but climbed equally quickly when I ran into more traffic. I escaped the city, hit the highway, and the temp relaxed back to the mid point and when I turned on the heater the temp actually fell to the 1/4 point (between coldest and mid point).

I'm not a mechanic but have done some parts changing in my time. The last time I had this problem (Toyota pick up) it was the thermostat and I was able to change it myself.

1. Is this the likely culprit here? Are there other things I should consider?

2. How hard is it to change the thermostat on this car? Can I do it myself? Can I entrust it to almost any mechanic? (Audi dealier is inconveniently far away.)

Thanks.

 

Once i had air in my cooling system that made it over heat but that wasn't an audi.
How many miles do you have on your car?
if it's over 75K it's time for a timing belt tentioner waterpump and thermostate.

Someone can correct me if i'm wrong but on a japanese car when the water pump was on it's way out it liked to over heat from not enough water flow through the car. I would check that and teh termostat.

I had all the stuff stated above done by just a local car shop that had worked on VW cars before. so they knew the 1.8L but a cars a car any good mechenic can work on them they all come apart the same way long as you have a good service manual.
Thats just be though.
Some people are much more picky.
I say if they have worked on a lot of VW cars or audi's the local shop is going to be cheaper and normally faster getting you in.

 

Could be thermostat, water pump, fan, temp sensor, quite a number of possible culprits, best bet is to take it in as Blackraptor suggests unless you have the diagnostic tools/skills to DIY.

 

Took a chance on a local "European Car Specialist" (see related post).

He found that the fans weren't running and traced that to corrosion on the four fuses and terminals on top of the battery box. He cleaned off terminals and replaced the fuses and says the problem is solved.

I had noticed that the fans weren't running when I turned the car off so his diagnosis is certainly consistent. I pick the car up today and will be able to check this out.

 

You lucked out. I had the same problem a couple of weeks ago and it was the thermostat.

 

Hi there, I am experiencing a really bad overheating problem with my Audi TT, I replaced the thermostat, temp sensor and radiator switch and I am still having the same issue. I know the fan fuse when out on me in the past but it's doesn't seem to be that, I know someone is going to say it may be your radiator, but how can I know for sure that's the problem before I replace it?