RPM fluctuation while driving at certain speed

[krisis32]

While driving around at range from 60 to 80 kilometer per hour the rpm jerks or fluctuation a lot.
Feels like car want's to go ahead, but something is holding it back a little. Once you get over 85 works great. Doesn't matter if the car is warm or cold.

This is how it kind of feels, but only when accelerating -
It only happens when driving at around that speed. If I floor it, then there is no issue and car gain speed smoothly. Or if I use S on multitronic, then the jerking isn't as noticeable and feels more smooth.

At service guy told me the ERG is clogged and needs cleaning, but couldn't tell me why there is such issue. There were no other errors.
I really do hope it's not torque converter as it can be quite expensive to replace.
Will bring the car tomorrow to another repair shop to see what they can figure out.

Anyone has some guesses or similar issue?

 

[BahnStormer77]

What year is your one? I know the multitronics have known issues with the older 6-plate clutches, but I can't remember when they swapped those on the A6. Maybe somebody here can advised which generations of the A6 have different multitronic versions.

What you're describing sounds like the clutch slipping: low RPM, high gear and increase the torque (accelerate gently)... but the issue will then go away if you accelerate harder as it will shift ratios, making the torque difference that has to be handled by the clutch a lot lower as it is in the equivalent of being in a lower gear.