Abstract: An improved isolated oil pan assembly is provided for use on an internal combustion engine, such as a diesel engine, thereby eliminating a serious problem associated with prior engines of this type; namely, a source of undesirable noise. The improved pan assembly includes a pan which is secured to the underside of the engine block by a plurality of fastening means spaced from one another and disposed inwardly from the periphery of the pan. Each fastening means is positioned within an elongated sleeve-like pocket which is recessed from the underside of the pan and extends through and protrudes from an opening formed in the upper end of the pocket. The protruding portion of the fastening means is secured to a rigid stationary member disposed within the interior of the engine block. Each fastening means is isolated from the corresponding oil pan pocket by an isolator formed of resilient, vibration isolating, oil impervious material.