Turbocharged cars like the Audi RS6 require many attributes of the engine to be performing perfectly to maintain optimum performance. One of the cheapest fixes and hardest to diagnose, is vacuum and boost leaks. Many of the emissions and accessories on cars are controlled from vacuum generated in the intake system of the engine. Components related to performance and accessories, are all tied together into the same system. One leak in any rubber hose can lead to degraded performance from a turbocharged engine.
I was inspecting the condition of my stock rubber vacuum lines in the RS6, and a few of them fell apart in my hands. I decided that instead of replacing one, I would replace them all with quality silicon hoses. I ordered 15' feet of blue silicon hose from ECS tuning, which is my usual preferred vendor for Audi/VW performance parts. In this blog post, I am only replacing the small braided rubber vacuum hosts on top of the engine.
To replace the hoses, you first must remove the carbon fiber air intake system on top of the engine. This requires removing the silver air intake tubes, two nuts on the bottom of each black air intake tube, and a large center bolt.
After you have the air intake system off, you should located all of the vacuum hoses. I previously replaced the vacuum line to the bypass valves, but I am still going to replace them again with the quality hosts from ECS Tuning.
Before going any further, you should stuff rags down inside the turbo inlet ports on the back of the engine. If anything falls into them, you are going to have serious problems.
The most difficult task of replacing the vacuum lines, is removing the stock metal clamps on the ends. I don't have a special tool for this and if you can find one, I would recommend it! This could have been a thirty minute job, but removing all of those clamps turned into two hours.
While I was installing the vacuum hosts, I also relocated the pickup line for my boost gauge to the fuel pressure regulator. The distance between the fuel pressure regulator and the intake port, was not a far enough distance to connect a boost guage T-fitting. I had to loop the silicon hose around the regulator and back to the intake port to allow for enough distance to install the T-fitting. If you do not have a boost gauge, then you will not have to worry about this problem.
I used small zip ties to tighten the ends of the silicon lines. Pull the zip ties snug and then cut them off with a side cutter. Once you are complete with changing all of the lines, reinspect all of the ends to make sure you didn't miss installing a zip tie.
When complete, you should have something that looks like the following.
Before putting the intake back on, make sure that you remove the rags from the turbo inlet ports. You should also unplug the batter for ten minutes, and reset the ECU codes, to ensure the engine takes advantage of any leaks fixed.
I hope this has been helpful and let me know if you have any question.