motor mount on left side is broken or loose on 2002 Mercedes-Benz E430 4MATIC

Had a bad experience with mechanic. Claimed the heads cracked resurfaced them. When he returned car a vibration under hood, we looked and when you put foot of gas left side of engine lifts up out of the car

Asked by for the 2002 Mercedes-Benz E430 4MATIC
If heads were 'cracked' not warped , then I wouldn't be worried about an engine mount. I'd sell the car before it blows up.
2 more answers
for sure the motor mounts are bad or not mounted correctly...was it that way BEFORE the repair?
I cant see how doing any head work would break a motor mount but if the technician did loosen the motor mounts to lift the engine in order to aid in the R&I of the heads they may have forgotten to tighten it after repairs were completed. I would bring it back and have them recheck their work and look to see if the mount is broken or loose, tighten or replace mount as needed.