After receiving a verbal turnover; a Line Mechanic completed an engine mount replacement on a Saab 340 aircraft. Previous Mechanic mentioned he had removed the 'old' mount and the 'new' mount was already 'in position.' The 'old' engine mount was later discovered still installed at the same location.

Narrative

Mechanic 'X' and myself were instructed to blend the aft engine tower mount and replace the engine mounts on a Saab 340 aircraft. I had started with the blending process and when that was finished we were waiting on confirmation that the blend was still in limits; so I then proceeded to replace the engine mounts. We were short hardware for the mounting bolts. We had ordered more; but were still short. I had enough [hardware] for the side I was working which was the right side. we had one for the left. Mechanic 'X' had been working on the left side when he 'passed down' [gave verbal turnover] to me because of getting switched to another plane.He told me the new mount was 'on' and secured with old hardware loosely. I acknowledged what he told me and I then put the one new bolt in and waited for the other three to arrive. When they arrived I took the old bolts out and immediately replaced them with the new hardware that had come. I torqued the bolts and safetied. I proceeded to then continue with the rest of the install. The 'passdown' [turnover] that I had gotten from my fellow Mechanic verbally; was plain and clear. And maybe with both good and bad mounts on the table at the same time it could have been a possibility that it [bad mount] may have been set down in doing the green Tag and then grabbed again by mistake and reinstalled on the engine. The engine was removed and correct mount was put on. I suggest getting a better turnover from fellow Mechanics rather than just verbal; actually show part and possibly write it down.