Car vibrates
The car begins to vibrate as soon as I turn the key in the ignition, and continues to do so until I turn it off. It sometimes gets worse as the car idles at red lights. So far, I've replaced the rear motor mount and the harmonic balancer, but the problem persists. My mechanic says he can't think of any other reason the car would continue to shudder other than "old age loosening things up". I think it's worth further exploration. Any ideas?