I just had a new clutch installed last week. Now, whenever I shift from 2nd into 3rd or if I'm cruizing in 4th at around 40mph, there's a virating/harmonic noise whenever I depress the accelerator. The mechaninc who installed the clutch thought it sounded like a heat-shield, but everything checked out fine. No issues with the clutch either.

Amy suggestions? It has never done this in the 6/years that I've owned the car until the new clutch was installed. Thanks!

 

Check your shifter linkage.