The M112's I've been in have been fairly quiet in the cabin, but they have a rougher quality to them than the M104. They've idled nowhere nearly as smooth as the M104.

But who knows, it could've been motor mounts. Put worn out motor mounts on the M104 or the M113, and you can definitely feel the vibration in the cabin.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".