V2Rocket

A few days ago I went in to check the tension on my timing belt and while I was in there tweaked the balance belt a bit too. It looked like it had slackened a bit and so I got it back to a satisfactory amount of tension.

I know for a fact that the belt is lined up in regards to TDC/BDC on the pulleys, as I had to fix that some time ago when the vibration was pretty bad.

Is it possible that with my slight tightening I somehow threw off the balance system and caused more vibration?

Techno Duck

Unless you took the belt off then no. Verify the marks.. its very easy to be one tooth off.

V2Rocket

The teeth on the balance shaft pulleys and the crank pulley did not move at all, all that may have changed would have been the balance belt tensioner.

Maybe its my imagination? lol

jharding

Does the vibration occur at idle or at around 3k rpm? If at idle then it's most likely a bad motor mount (exhaust side usually fails first). If the vibration is at around 3k rpm then smooths out the balance shafts aren't aligned correctly.

M758

Mis-aligned our 180 deg out of phase balance shafts can increase the vibes.

V2Rocket

Motor mounts have less than 10k on them, replaced in March '06. The vibration is only at idle....maybe its just because its getting colder :P

moorepower

My guess would be a small vacuum leak or something similar, causing a rough idle. I had a vacuum leak on my car last year, and it was more noticable when it was cold outside. Or it seemed so, anyway.

Mongo

Second the 180 OOB on the lower balance shaft..