A cover assembly is provided for an engine block having at least one sidewall defining a service opening therein. The cover assembly includes a plate defining an opening therein, a fastening element rotatably disposed in the opening, and a clamping element. The plate has a first side, and a second side. The second side is configured to seat against an outer surface of the sidewall. The fastening element has a first portion configured to be axially restricted by the plate, and a second portion axially extending from the first portion. The second portion is disposed beyond the second side. The clamping element includes a central core disposed at the second side. The central core defines a threaded receptacle configured to engage with the second portion. The clamping element also includes multiple arms that radial extend from the central core and seat against an inner surface of the sidewall.