Pump, Engine Oil: Description

Courtesy of CHRYSLER GROUP, LLC

The vane type engine oil pump is mounted to the underside of the cylinder block and is driven by the oil pump chain off the crankshaft at a 1:1 drive ratio:

• This pump location improves efficiency compared to an on-crankshaft location.
• The pump is driven with a silent chain which is tensioned using a spring loaded tensioner.
• The pump is not timed to the engine.
• An internal mechanical ball and spring type relief valve prevents excess pressure in the engine by dumping oil into the sump and provides emergency protection at conditions such as a cold start with high engine speed.
• The pump has a moving slide mechanism for variable displacement capability and an on-off solenoid for two-stage pressure regulation.
• The pump and the solenoid are not to be disassembled.
• Both components are non-serviceable items and are to be replaced as a complete assembly.