Scroll compressor designs are provided to minimize vibration, sound, and noise transmission. The scroll compressor has a bearing housing, and orbiting and non-orbiting scroll members. The non-orbiting scroll member has a radially extending flanged portion with at least one aperture substantially aligned with the axially extending bore. At least one fastener is disposed within the aperture and the bore. A sound isolation member contacts at least one of the non-orbiting scroll member, the fastener, or the bearing housing, to reduce or eliminate noise transmission. The sound isolation member may be formed of a polymeric composite having an acoustic impedance value greater than the surrounding materials. The sound isolation member may be an annular washer, an O-ring, or a biasing member, by way of non-limiting example. In other variations, fluid passages are provided within the fastener and/or bearing housing to facilitate entry of lubricant oil to further dampen sound and noise.

A cover for an engine assembly of a motor vehicle is attached at one end by a hinge and at the other end by sockets interlocking with engine projections. The engine assembly has a first hinge portion located at a top, rearward end of the engine assembly, and has first and second structural projections extending upwardly and spaced from the first hinge portion. The cover has a foam body overmolded onto a rigid substrate. The substrate has an integral second hinge portion to engage the first hinge portion. The foam body is formed of polyurethane foam with first and second sockets releasably receiving the first and second projections, respectively, to hold the cover at an installed position. The soft cover provides excellent noise and vibration performance together with a desired visual appearance. Manual installation and removal of the cover is done easily and without any tools or removable fasteners.