I posted this on the TT board but wanted to check in here.

my rough 1.8t 2001 225hp w.130k runs rough.

I have spent tons of time and months trying to diagnos. I gave up and took it to a mechanic.

he is pretty dang sure, and has me convinced, that my rotating mass is out of balance. he suggested clutch/fly-wheel assembly, harmonic balancer, or a piston sleeve or bent rod.

does this make sense?

has anyone replaced a harmonic balancer?

thanks!

Peter Schmid

 

Use the computer to check data blocks and make sure it's not misfiring (14?). Also check your fuel trim (32) and mass air flow readings(?). If all of that is ok, then it's probably the dual mass flywheel. I've seen a couple of them get stuck off to one side, causing it to be out of balance. I've never seen a balancer on a TT go bad, and I'm not even sure if they can. They arn't hard to get to, but odds are that it's the flywheel.