Description and principle of operation of exhaust toxicity reduction (Defender 2007+)

Exhaust Gas Recirculation (EGR) Component Locations

Pos.	Spare part number	Name
1	-	Sensor (shown for illustrative purposes only) manifold Absolute Pressure (MAP)
2	-	EGR valve
3	-	EGR system heat exchanger
4	-	Pipes for gas transfer and mixing

Review

The EGR system includes the following components:

• EGR modulator
• EGR system heat exchanger
• Gas Transfer Pipe and Gas Mixer

The exhaust gas directly from the exhaust pipe enters the EGR heat exchanger, where it is cooled by passing through a bundle of water pipes integrated into the overall engine cooling system. On the cold side of the heat exchanger is the EGR valve. This valve is driven by an electric motor - it is controlled by the engine control unit (ECM), which provides different amounts of EGR recirculation depending on engine operation. When the engine is turned off, the valve opens and closes several times to release any deposits that may have accumulated on it during operation.

The EGR pipe transports the cooled gas to the mixer, where the gas is mixed with the incoming air stream.



The ECM monitors the EGR system function and stores fault codes if a fault occurs. The EGR valve can also be activated to allow testing using the Land Rover approved diagnostic system.

Placement of engine crankcase ventilation components

Pos.	Spare part number	Name
1	-	Cylinder head cover
2	-	Gas Transfer Pipeline
3	-	Air intake manifold
4	-	Oil separator

Review

The engine crankcase ventilation system regulates the pressure increase during engine operation. To prevent excessive oil loss or consumption, the separator ensures that all gases leaving the engine crankcase during operation are separated from any oil particles.

The crankcase gas enters the oil separator block, located under the engine cam cover, due to the difference between the crankcase pressure and the air intake manifold pressure. The oil separator removes oil from the crankcase gases. The crankcase pressure is released into the air intake system through the crankcase ventilation manifold. The separated oil flows from the oil separator into the oil pan through the internal engine oil passages.