Engine vibration?

[xspeed02]

So I get the car back today and it runs great, only problem is, with my new motor mounts, the vibration has been amplified ridiculously. Anything above about 2k or so the motor vibrates like a b****. I think it might be the harmonic balancer, the engine has 176k miles on it, do you think I should replace that and see if that fixes it? Or do you think the engine internals are so out of balance that it's vibrating like crazy. Mike at Dayton 5.0 looked at the harmonic balancer and it looks like its wobbling pretty bad at high rpms. Looking for a 2nd opinion. Is this a common thing to go wrong with engines later on in life? I've had some friends tell me they had this happen to them, just wanted to ask more people on a wider scale before I go drop the bucks for another balancer.

[95_MUSTANG_95]

I just posted yesterday about a potential Harmonic Balancer problem. In the process of removing the bolt that secures the balancer/pulley I inadvertantly moved the Harmonic Balancer in relation to the crank pulley. I know I screwed it up.

My engine ran as you described; rough at idle and shaking like H*** at 1500 to 2k. Still rough at higher rpms. Kind of like a timing problem.

Well, I replaced the Harmonic Balancer last night after work and it ran like a top. $100 bucks and 40 minutes. The balancer was new but, I could have gone to a salavage yard and pulled my own for probably 20-40 bucks.

I'd throw a timing light on first before replacing the balancer. If the timing is out it could mean the outter vibration damper has slipped in relation to the crank pulley or you have a ICM / Dist. / Hall Sensor problem.