Oil Pan Inspection Plug

The MOROSO Oil Pan Inspection Plug (MPN 23970) is a weld-on bung system designed for engine builders, performance tuners, and shade-tree mechanics who need reliable access to monitor oil condition and perform mid-service inspections without draining the entire pan. This steel-bodied inspection plug provides a practical solution for custom engine builds, competition vehicles, and heavily modified street engines where quick diagnostics and preventative maintenance matter. Whether you're tracking oil degradation in a high-performance engine or monitoring contamination in a freshly rebuilt mill, this purpose-built component eliminates the need for full oil changes just to inspect pan contents.

Engineered with a 1 inch NPT threaded interface, the weld-on steel bung integrates permanently into your oil pan for maximum durability and zero leakage under operating pressure and thermal cycling. The removable aluminum plug seals the opening when not in use, offering a lightweight, corrosion-resistant cap that withstands engine bay temperatures and frequent removal cycles. The natural finish aluminum plug won't corrode or seize, ensuring that repeated inspection access remains effortless across multiple oil service intervals. This design eliminates improvised drain plugs or poorly-sealed inspection ports that compromise engine protection and create messy spill hazards during routine checks.

Professionals and enthusiasts running racing engines, supercharged builds, or extended-drain synthetic oil programs benefit most from this inspection system, as it allows real-time oil analysis without full pan drains. Installation requires welding the steel bung to your oil pan—a straightforward process for anyone with basic welding skills or access to a fabrication shop. Compatible with any custom or aftermarket oil pan featuring sufficient flat surface area near the pan sump, the MOROSO inspection plug integrates seamlessly into engine bays where oil health monitoring supports data-driven maintenance decisions and extends component life.