Oil Pre-Heater - Self Contained

The MOROSO Oil Pre-Heater Self Contained (model 23991) is a 400-watt engine oil heating system designed to bring lubricant to operating temperature before cold-weather starts or extended idle periods. This self-contained pre-heater unit eliminates the thermal stress of running cold oil through critical engine bearings, reducing wear and extending powertrain life—a proven concern for performance builders, fleet operators, and high-mileage enthusiasts working in northern climates or storing vehicles seasonally.

The unit features a 110V/120V electrical rating with a 3-foot power cord and mounts via a weld-on aluminum fitting with 1/2-inch NPT threads—a standard interface compatible with most oil pan sumps and remote filter housings. The internal element design means the heating element is sealed within the oil circuit, eliminating external exposure and corrosion concerns. At 0.64 lbs and measuring 6.9 x 1.35 x 9.6 inches, the compact footprint allows integration into tight engine bays without major reconfiguration. The 400-watt capacity delivers predictable heat output for gradual, controlled oil warming rather than thermal shock.

This pre-heater is essential for serious cold-start protection in vintage restorations, winter storage protocols, and professional fleet maintenance where minimizing cold-running cycles translates directly to lower bearing load and reduced combustion chamber deposit buildup. Off-road builders and track enthusiasts also use oil pre-heaters during multi-day events to condition fresh oil before engine firing, ensuring full film strength from the first crank. Installation requires access to the oil pan or filter block and basic welding skills to mount the bung securely.

MOROSO has built reputation in performance heating and cooling for over 60 years, and this model reflects straightforward engineering: a resistive heating element in an aluminum housing, designed to work with standard 120V household or shop power without external control modules. The internal design eliminates the risk of thermostat failure external to the engine, keeping the heating function entirely passive until power is applied.