asics

Several months ago I had a torn TBB. The dealer repaired th TBB but the turbos were much louder than before. I drove the car for a couple of months this way but finally took it in for some other service and mentioned the turbo noise. The dealer told me he would have to call Audi to see if the turbos would be covered under warrentee because I had waited so long to bring in the car and because I had mentioned that I had gone to an Audi Quatro Club driving school when the first TBB had torn. Well I was real mad and I said that there were no warning lights and I had no way of knowing that the TBB was torn and or what the cause of the turbo noise was. He said that he would call Audi after he found out what the noise was and check the warrentee status.

I got a call later that day and found out that the TBB was torn again and that it would take several days to get a new TBB and I could not drive the car in the mean time because it could damage the turbos.

My thoughts/questions are these:
How can you know if you have a torn TBB. I have apparently had two and the car ran basically the same as usual except sometimes it didn't seem to have as much power.
I have gotten two different oppinions on damage to the turbos as the result of a torn TBB. One oppinion (from posts on this board and one Audi service manager) is that the ECU will immidiatly reduce boost so the tubo won't overspeed. The other (from annother Audi service manager and a turbo overhaul company)is that with a large hole in the pressure side of the turbo system the wastegate will stay closed to try to make the required boost and the turbo will overspeed, especially if the tear is sudden.
Is it possible for the service dept. to have damaged the first TBB when they installed it so that it was already damaged when I got the car back.
Finally, it seems as if Audi doesn't feel as though going to a driving school is "normal use" of their cars. Probably it is a good idea to keep any news about going to driving schools to yourself when you take your car in for service.

Also, at least some, service managers believe that we need to pull over to the side of the road and call Audi roadside assistance anytime we have any hint of a problem.

LCP

You figured out how to know if you've torn a TBB -- the other way is to visually inspect it, but that often requires at least partial removal.

The turbo can overspool and it won't reduce instantly, but it will be pretty close; hopefully and probably before damage occurs -- I don't think mine's damaged.

With a torn TBB, you should not harm your turbos so long as you don't use the turbos much -- how do you do this? By not giving it full throttle, certainly not if the car is chipped. A few PSI running through the hoses probably isn't enough to blow significant amounts of air through a mild tear, but could be if the tear were huge.

I meet my service manager at track events. 8^)

ack67

If they're telling you you can't drive it until the TBB is repaired because it will damage the turbos, then by definition they've already been damaged by having 2 torn TBB's. If, on the other hand, a torn TBB won't damage the turbos, then why can't you drive your car while waiting for the parts? Demand that the damaged turbos be replaced.

timcar

The car broke. It's under warranty. Fix it.

Audiablo

<p><img src=http://www.vizsoft.com/~oliver/A6spin.gif>

asics

The service manager said that the warrantee says something about no track use or something like that. Of course I say that the Audi club driving school is not racing but rather instruction. He also said that the warrantee also requires that you do whatever you reasonably can to stop further damage, to which I said that I have no way of telling if something serious is happening if I get no warning other than a whine from the turbos.

asics

Thats a very logical analysis but I'm afraid the service manager would say that the damage occurs over time so that there would be serious damage only if the car was driven for an extended period with a torn TBB.
The turbo overhaul place I talked to said that the damage would probably occur at the time the boot blew because the ECU would take some time to recognize the leak and the wastegate would take some time to open. The turbos speed up very fast, especially at high power settings so there would be little time to react. Of course if this is true I wouldn't have been able to do anything about it.
By the way it is possible that the turbo would actually slow down if you had a large leak in the TBB. A centrifugal compressor will actually take more power rather than less when it flows more air (which it does when there is a leak). The problem is that the ECU will close the wastegate in order to try to bring up the pressure to where it should be. If the leak is large enough the turbo may overspeed before it reaches the required pressure or the ECU sees the leak and opens the wastegate to save the turbo. The question becomes, is the turbine on these turbos large enough to supply enough power to the compressor to cause the two to overspeed at full throttle.

asics

When the service manager called me on Friday he said the the turbo whine was caused by the TBB tear and that replacing it should get rid of the noise and he implied that the turbos were not actually damaged. What I am curious about is, if the car can not be driven because the turbos would be damaged and I have been driving it this way since the last TBB repair then presumably the turbos must already be damaged.

I really don't know what to think, except that they don't really know what the heck is going on but just in case they will keep the car until it's fixed. All I know is that I did not do anything to abuse the car and I certainly won't accept having to pay for any of the repairs.

AK AL

sounds like another audi experience, call customer care and complian about the dealer ,I would find a different dealer soon!

Jack Orr

Simply refer them to the Audi experience, which is the featured article on the home page- as we speak. So much for the idea that a track experience voids a warranty. Schools and such are NOT racing! And the referenced event was sponsored by AUDI.