The coolant flange is one of the more common parts to fail on a 1.8T. I have witnessed three different situations where the original flange failed right around 120k-140k miles, I have heard that it can happen sooner as well. Typically when it does fail, it is accompanied by a large coolant leak that might leave you stranded. The sooner you can catch a leaky coolant flange, the better off you are.
Although one may be tempted to purchase a more affordable aftermarket coolant flange, I have had better luck with Genuine Audi/VW flanges from the dealer or online. The way I look at is that the original had lasted 100k miles, it's worth the few extra dollars to buy a flange from the dealer that you know is a quality piece. The aftermarket ones tend to have quality issues that may affect sealing later down the road such as warping and believe me, this is not a job you want to have to do twice.
Make sure you pick up extra coolant as well as a replacement o ring for the coolant sensor, the larger main o ring that seals against the cylinder head should be included with your coolant flange.
Once you have all the parts you need, let's get started!
