We're having a problem with a late 2001 A6 avant. It'a fitted with the 2.5 v6 tdi, has the Multitronic CVT system, and has done 140,000 miles.
The problem we're having is that the car seems to shudder, but not in reverse like some people have reported. It happens when driving forward, at pretty much any speed. It's not a violent shudder, something more akin to a manual car with a dodgy clutch.
As there's absolutely shedloads of torque, the "box", always seems to try and find the lowest possible gearing and this is when the problem occurs. You can put the car in "manual" mode and if you keep the revs above about 2000 - where in a normal car you'd have no reason to do anything with the clutch - the car works grear albeit with rather poor economy.
The gearbox also seems to "hunt", almost oscillate between two ratios. It's as if it's looking for the ultimate ratio, changes into a higher ratio, then decides that it's a bit too high, and changes down again. Then, about a second later it'll change back into the higher ratio, then back into lower ratio, ad infinitum. You just hear the engine note rise a little, and see the rev needle going up...And then down....And then up...And then down...
So from this, we reckon that the wet multiplate clutch is needing replaced. The car was in our local franchise so they did an "Oilchange Service" on the box but to no avail. According to the receptionist/service manager if that didn't solve the problem we need a new gearbox....But speaking to the head mechanic Audi have had a design change from, I forget the numbers exactly but something like, a five plate clutch to a seven plate clutch. Apparently there's even a modification kit available.
The franchise is a small place and doesn't have a lot of room to engage in fairly involved vorspring durch Technik type activities, but I'm sure somebody somewhere will have done it.
Any similar experiences anybody?
We recently bought the car in a private sale and the manufacturers warranty has expired. So we're left no option but to try and find the solution ourselves...Or pay the dealer a lot of money for a new gearbox.