My 99 Accord LX 2.3, 166,000 miles, has been vibrating at idle for several years. Not real bad, but kind of annoying. Runs great going down the road and still delivers decent gas mileage. Did a complete timing belt job a little over a year ago and replaced all the engine mounts about 5 years ago. (Yes, I've done these jobs successfully before on this and another Honda I own.) A few weeks ago, I happened to be looking around under the hood and noticed the alternator/AC belt has been rubbing the lower timing belt cover, adjacent to where the timing belt tensioner adjuster nut protrudes from the cover. This issue has recently arisen, since I would've noticed something like this when I took off the timing belt cover to replace the belt. I also noticed the harmonic balancer/crankshaft pulley wobbles somewhat at idle. I torqued the crankshaft bolt to the proper 181 ft lbs when I did the timing belt job, so I know that's not the problem. Also, both the alternator/AC and power steering belts are properly adjusted and I replaced most of the ignition parts (wires, plugs, distributor cap, rotor) recently, as well as recently cleaned the throttle body and IAC valve, so I doubt the vibration is caused by something else.

I've read on some message boards about some Honda harmonic balancer rubber separation due to age and exposure to the elements (e.g. road salt) and wondered if anyone else out there has experienced this? I'm considering buying a new Genuine Honda harmonic balancer, but want to make sure before I drop over $200 on one. Thanks!