Lubrication System-Low Pressure

Lubrication System-Low-Pressure

Part 1 Of 2:

Part 2 Of 2:

Low-Pressure Oil Flow

The lubrication system is pressure regulated, cooled, and full flow filtered. In addition to providing engine lubrication, it supplies oil to the high pressure oil system to control fuel delivery in the fuel injectors.

The following sequence describes lube oil flow through the major oil system components:
1. Oil pan (sump).
2. Oil pick-up tube and screen.
3. The low pressure oil pump is a gerotor type contained in the front cover. The gerotor assembly consists of an outer and an inner gear. The inner gear is driven by the crankshaft. The pump inlet and outlet passages are through ports in the front cover.
^ Oil pressure regulator (bypass) controls lube oil pressure via a spring loaded plunger relieving oil back to the inlet of the pump once operating pressure has exceeded 517 kPa (75 psi).
4. The oil cooler cover receives oil from the oil pump and cools it in the oil cooler, which is located underneath the oil cooler housing.
^ The cooler bypass valves open in the event that the oil cooler base and/or cooler becomes restricted.
5. The oil filter housing contains a paper type element. Unfiltered oil flows down and around the outside of the filter and then up through the center standpipe.
^ The oil filter bypass allows oil to pass directly to the main oil gallery should the filter become restricted.
6. Turbocharger and drive gears.
^ Cooled and filtered oil supplied from the oil cooler base lubricates the turbocharger bearings and provides hydraulic pressure for the turbocharger variable vane hydraulic control valve. Oil drains from the turbocharger through a drain tube back to the high pressure hydraulic pump cover.
7. Main galleries. Cooled and filtered oil supplied from the oil cooler base fills the main galleries to distribute oil to the following components via passages machined within the crankcase.
1. Hydraulic cam followers.
2. Camshaft main journals.
3. Crankshaft main journals.
4. Connecting rod bearings receive pressurized oil from the main bearings via drilled passages within the crankshaft.
5. Rocker arms receive their lube oil from the hydraulic cam followers via the push rods. Oil drains back to the sump through holes located in the cylinder head.
6. Piston cooling tubes.
8. High pressure hydraulic pump oil reservoir.
^ This reservoir (below oil cooler) has a constant supply of oil for the pressure hydraulic oil pump. It has an approximate capacity of 0.9 L (0.95 qt.).