Just purchased a 2001 A6 2.7t, trying to get it perfect but the engine fluctuates between 1000 and 2000 rpms during acceleration. Its jumping up and down only 100 rpms. Accelerating above 2000 rpms this does not happen.

During regular driving, this can be really annoying. Any help would be greatly appreciated. Thanks in advance.

 

A6 is also an automatic with 96k. Unknown of service history but upon inspection of timing belt and hoses, they look pretty new.