hey guys! i need your help again. i had my front & left rear engine mounts replaced. after the installation, the dashboard vibrates even more especially when i stop & step on the brake. it also vibrates when i'm turning the steering wheel whether i'm on reverse or drive. my mechanic says it should vibrate because the mounts are still new. is that true? he did not use OEM engine mounts. also, when he adjusts the idle speed to high, the vibration stops but i don't think that's the right way to solve the problem. what can be the problem? any ideas? thanks in advance!