There is an issue that seems to be present on facelift cars. At the back end of the engine bay by the firewall, there is a metal clip that should be about 20mm away from a coolant pipe. On the facelift cars, it seems to be about 5-6mm away. (Pre facelift cars should check too but they are said to be about 20mm)
Under hard acceleration, the engine rocks and the metal clip rubs against the coolant hose. A friend of mine with a FL RS6 punctured a hole in this pipe and it spilt the entire contents of his coolant tank all over his nice hot engine. The car had to be recovered by Audi and it was observed that the clip had worked its way through the hose. He messaged to tell me what happened to him so I went and measured the gap on mine and it was the same, 5-6mm away from the hose. It has also been checked on a few other facelift cars with the same 5-6mm measurements, dyno tests prove that it touches under hard acceleration when the engine rocks so this has been visually confirmed.
The hose is a nightmare to change should you rupture it, the whole bulkhead needs to be removed so it's not a 5min fix.
This happened a couple of months ago and I was meaning to post up about it at the time but forgot all about it. It's a 2min job to fix, the clip just needs sliding along further to the right so you increase the gap between itself and the hose.
Back end of engine bay, by the firewall, drivers side...
Slide the clip along (Push it with a flat headed screwdriver)....
As said, it seems to be an issue on the facelift cars but It would be advisable to check your gaps and if necessary, push the clip further along so its physically impossible for it to rupture the hose. it would be a good idea to post your findings on the gap size to see if this 5-6mm gap is common or not (or just a case on a batch of FL RS6's) It may save some of you a lot of bother further down the line
