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.

 

Tires balanced improperly.......try that first before you go thinking of the hard stuff.