Description And Operation
Mechanical engine components are supplied with lubrication through a complex system of internal oil galleries in the engine block and cylinder head. The oil system pressure is created by a variable displacement oil pump and temperature controlled by a heat exchanger in the engine oil cooler.
The lubrication system also features an oil pump displacement control solenoid valve and a spin-on disposable engine oil filter.
The variable displacement oil pump can change its output through mechanical means and due to control commands from the Powertrain Control Module (PCM). The main features of the variable displacement oil pump are:
- Oil pump sprocket
- Oil pump body
- Mechanical oil drain regulator
- Engine oil pump displacement control solenoid
- Oil supply pressure regulator
- Oil pump supply outlet
- Oil pick-up inlet
The oil pump pick-up (1) is attached to the bottom of the engine block and not directly to the pump. An internal passage in the engine block (2) routes the oil from the pick-up to the oil pump inlet.
The function of the engine oil pump displacement control solenoid valve (1) is controlled by the Powertrain Control Module (PCM).
When the solenoid valve (1) is closed (Off), the oil pump's floating stator (5) moves completely to the left within the oil pump body (4). This is because the oil pressure in the left chamber is nearly equal to the oil pressure in the right chamber as regulated by the restriction (3) and the mechanical oil drain regulator (2). This is also the default position, maximum pump displacement.
Maximum displacement is 3.6 bar ± 0.4 bar (52 psi ± 6 psi) at 5000 rpm ± 100 rpm with engine load > 50% and oil temperature of 90°C ± 5°C (194°F ± 9°F).
When the solenoid valve is open (On), the oil in the chamber to the right of the stator drains through the solenoid valve back to the sump reducing oil pressure in the right camber causing the floating stator to move toward the right. This is the minimum pump displacement.
Minimum displacement is 1.3 bar ± 0.25 bar (19 psi ± 3.6 psi) at 2000 rpm ± 100 rpm with engine load > 20% and oil temperature of 80°C ± 5°C (176°F ± 9°F).
The oil filter features a rubber seal where it mounts to the oil pan.
Engine oil enters the oil filter base through oil inlet holes (1) and exits from the center (2) through the threaded mounting nipple.
Engine oil from the oil pump outlet passes through the engine block (3) and enters the oil filter.
From the oil filter outlet, oil enters the oil cooler inlet (A) and exits at the oil cooler outlet (B). From the oil cooler outlet oil is directed to the main oil gallery inside the engine block (1). From the main oil gallery, oil is routed to the cylinder head (2).
There is an additional filter screen in the oil supply channel to the cylinder head, which ensures that the oil directed to the cylinder head components is cleaned more thoroughly.