I just paid my mechanic to change the timing belt on my 04 sonata - has 85k miles. He told me when I was paying that I might need new motor mounts. When I started it up and drove thru the lot, it had a new massive vibration that wasn't there when I dropped it off. He now says that mount was probably cracked and when installer lifted engine it broke it entirely. I know that on many cars you must loosen the mount bolts before you begin. My question is - did the installer screw up by forgetting to loosen mount bolts, thereby breaking a perfectly good mount(s)?