My friend is having some probs with his 97' Civic EX Coupe, auto. He just got it tuned up, new belts, filters, plugs/wires, tires rotated and now he's having problems with a vibration when accelerating in the 45-50mph range and decelerating from the same mph. This is when, during normal driving, the car shifts into 4th gear. There is no vibration through the steering wheel, and there is no noise to speak of? Any ideas here? We're hoping it's not tranny related, maybe motor mounts? I thought wheel bearings, but wouldn't there be a noticable noise?
TIA,
Sean W.

 

is the car lowered? even if its not maybe the suspension is messed up, if its lowered without a camber kit then the tires from the rear will be choppy, and that would cause the vibration.

 

The car is stock height (for now), but thanks for the response. I don't know any of the quirks of Hondas (do Hondas even have quirks?) so I really don't know where to begin to look. I drive an 87' Pontiac Fiero GT, so I'm pretty far behind the technology curve when it comes to cars (which is where I'm going to stay, I love my Fiero).