When you replaced the mounts, were you careful about the bolts you used to attach them to the engine bracket? The original bolts were longer and used nuts, whereas the bolts in the new style screw into the mount itself without nuts. If you use the original M8x50 bolts with new mounts, they will screw straight into through the mount flange and damage the mount. The new bolts should be 38 or 42mm long, depending on which engine bracket you have. Also, did you make sure the rubber lip on the mounts were tucked under the recess on the cross member, so that sat flush?