I'll start by saying that I am a new Audi owner, and I am just now starting to get a decent understanding of the car, but I am still at the point where I can regurgitate information but I still do not fully understand the details.

I just got my car back from the shop and they seem to think that there is some issue with the turbo and wastegate function and this is causing overboost which in turn is causes the car to shut down the fuel supply to prevent damage. I have a 2001 TT 225 (AMU). The mechanic was able to reach down and move the lever between the turbo and wastegate. He said he felt some resistance and then it moved freely so he thought there might have been some carbon build-up. After that the car ran great for a few passes and then started doing this again. So he concluded that move likely there is something warped or a bigger issue than just carbon preventing the turbo and wastegate to function properly.

So.....he said I may need a new turbo or I might be able to have this one rebuilt or machined and a new bearing put in.

With that being said.....any suggestions? I am looking for a Bentley book for my car so I can see how difficult it will be to remove the turbo to get a better feel for what is going on. Who knows, maybe I will remove the turbo and be able to find whats causing the hang-up. But I am also willing to just replace the turbo if that makes sense. Do they make a rebuild kit that might fix this problem?
And also, If I do need to get a new turbo, and suggestions? I am looking for something that is inexpensive but very adequate!

Thanks!

 

He should NOT be able to move the waste gate by hand. There are two nuts on the wastegate shaft that may just need readjusted. Another 225 owner should be able to tell you where each nut should be.

 

Oh really? He said he was able to get it hand back there after removing the intake, and it was difficult to move but he was able to pull on the shaft enough to tell it was scraping a little but then freed up. It doesn't ALWAYS overboost and cut the fuel, but it does it more often than not.
Does that still sound like its potentially out of adjustment? Or more like its worn somehow? The car has 95k and it was bought used. The guy at the shop also told me it has a new washer, so he thinks someone had the turbo off before.

I really appreciate the info. I spend a ridiculous amount of time online trying to learn all that I can about this car.

 

Also I have some slight turbo flutter. Not every single time, but more often than not I get a little flutter.

 

Do you have a stock dv? Could be a torn diaphragm. If you decide to buy new, I'll take that old turbo, a's a project.

 

Like said above, flutter could be a bad dv if stock.

Please read this Please run out to your car and check this for me.. - AudiFreaks

I can't remember if someone has info on where the nuts should be stock

 

Its the original stock DV. I will be doing some research and replacing it asap.

I will also check for slack in the wastegate shaft and try to see what the stock setting is. Thanks for that link.

I drove around today and didn't have any issues with overboost or limp mode. But I did notice inconsistent boost. Seems like sometimes it barely blew off, and other times it was a loud woosh. So I installed a boost gauge and will take it out tomorrow to see what kind of boost I am getting.