Land Rover Discovery: Variable Flow Oil Pump With Integral Vacuum Pump

1. Vacuum exhaust valve
2. Pressurized oil outlet to cylinder block
3. Center plate
4. Oil pressure control solenoid
5. Control ring
6. Vanes and rotor assembly
7. Oil pump cover
8. Control spring
9. Oil pump housing
10. Vacuum port connection to cylinder block
11. Vacuum pump vanes
12. Vacuum pump housing
13. Pump drive sprocket
14. Bolt
15. Control ring oil pressure surface
16. Rotor
17. Vanes

The variable flow oil pump with integral vacuum pump is attached to the cylinder block with four bolts. The input shaft of the variable flow oil pump with integral vacuum pump is fitted with a sprocket and is driven from the front of the crankshaft, by an auxiliary chain, at 0.84 times engine speed.

Variable Flow Oil Pump

The variable flow oil pump draws oil from the oil pan through a centrally mounted pick-up pipe. The oil is pressurized and pumped through a bore in the cylinder block. After passing through an anti-drain valve and a plate type oil cooler, the oil is filtered by a replaceable oil filter element installed in an oil filter housing.

The variable flow oil pump is a vane cell pump with an eccentrically mounted control ring. The variable flow oil pump has a volumetric flow control mechanism to reduce the required drive output. The flow delivery can be adjusted using the control ring. Applying oil pressure to the control ring allows it to be adjusted against the force of an opposing control spring.

The eccentricity of the control ring can be decreased or increased, with increasing eccentricity increasing the output flow. The output of the variable flow oil pump is adjusted appropriate to engine load and speed to reduce load on the engine. An oil pressure control solenoid, operated by a Pulse Width Modulation (PWM) signal from the ECM, adjusts the oil pressure to the control ring to adjust the output flow.

Vacuum Pump

The vane type vacuum pump is tandem to the oil pump, connected to the vacuum harness via a drilling in the engine block and a vacuum connector.

The vacuum produced by the vacuum pump is used to provide a vacuum for the brake booster on the braking system, the active engine mounts and the EGR cooler by-pass valve (EU4 and NAS only).

The vacuum pump extracts air from the brake servo through a vacuum pipe from the servo and a port in the cylinder block. The air extracted from the brake servo flows through the vacuum pipe connector which is equipped with a one way valve to prevent oil ingress into the brake system. The air is vented into the cylinder block via a vacuum exhaust valve.

OIL FILTER AND HOUSING ASSEMBLY

1. Cap
2. Oil filter element
3. Seal
4. Oil filter housing
5. Oil pressure and temperature sensor
6. Cylinder block connections

The oil filter and housing assembly is a casting which is mounted on the front of the cylinder block. The housing is secured to the cylinder head and cylinder block with three bolts.

The oil filter housing has three ports which connect with corresponding ports on the cylinder block. Two ports provide the oil pressure inlet and outlet connections and are sealed with floating tube seals. The third port is for service oil drain when the oil filter element is replaced.

A replaceable cartridge oil filter element is located in the oil filter housing.

A plastic cap seals the oil filter element to the oil filter housing. The oil filter element is fitted with an integral by-pass valve. If the oil filter element becomes contaminated, to the point that oil flow is restricted, the by-pass valve opens to allow oil to flow through the oil filter housing to avoid starving the engine of engine oil.

The oil filter housing has a service drain facility. When the cap is unscrewed 3-4 turns, a drain hole is opened allowing oil to drain into the crankcase.

This allows the oil filter element to be removed with no oil contamination of the engine or surroundings.

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