01 passat engine mounts

When I step on it going up a hill, or backing up a driveway, I get a rattle like sound. Seems to keep getting worse. A local mechanic thinks it is the engine mounts. The odd thing is, if I switch from the automatic to the shifter, the noise goes away. Has anyone else run into this. I hate to start replacing engine mounts if the problem is bigger and elsewhere. FYI its the 1.8t - the one with the sludge issues. The engine was replace by vw about a year or so ago.

its vibrating badly thats why it produces that sound