Engine Lubrication: Description and Operation

GENERAL
This engine is a 90 degree V8 engine with indirect-type combustion chambers.

Oil Pump Operation
A gear-type oil pump pressurizes the oil with an enclosed pressure regulator. The oil pump uses a 552 kPa (80 psi) pressure regulator spring. Bronze bushings in the gears, and a plate support the gear shafts. An oil pump drive operates the oil pump. The oil pump drive is driven by the camshaft.
Oil Flow
The oil pump draws non-pressurized oil through a pickup screen and pipe and pressurizes the oil distribution system. The pickup screen and the pipe are submerged in oil inside the oil pan. The oil flows from the oil pump to an oil cooler that cools the oil. The oil cooler is located by the radiator. The oil cooler bypass valve protects the oil cooler from high pressures during cold ambient temperatures start up. The oil flows from the oil cooler or from the bypass valve to a full-flow oil filter. The oil cooler bypass valve is located in the engine block oil gallery to oil cooler passage. The oil filter bypass valve protects the engine from operating without lubrication. The oil filter bypass valve is located in the engine block above the oil filter.

The oil flows from the oil filter or the bypass valve to the main oil galleries. An oil pressure sensor is located on the left main oil gallery. The oil flows from the main oil galleries to the camshaft bearing bores. The channel in the camshaft bearing bores supplies the oil to the camshaft bearings and to the main bearing oil galleries. Oil flows from the channel in the upper main bearing shells to the holes for the piston oil spray nozzles. The piston oil spray nozzles are press-fit into the block. The piston oil spray nozzles spray oil to the underside of the pistons. This oil spray cools the pistons. The oil flows from the upper main bearing shells to the crankshaft oil galleries. The crankshaft oil galleries supply oil to the connecting rod bearings. The oil flows from the main oil galleries to the valve lifters. Oil flows from the valve lifters through hollow valve pushrods, to the valve rocker arms. The oil then flows from the main oil galleries to the turbocharger. Oil from the turbocharger drains back to the crankcase through a gallery in the block.