Intake manifold (Freelander 2)

Pos.	Spare part number	Name
1	-	Intake air supply tract
2	-	Intake manifold
3	-	Cylinder head swirl port
4	-	Cylinder head filler port

The cylinder head and intake manifold on the TD4 engine are designed to optimize swirl levels across the entire engine speed range and deliver high volumes of air to the cylinders. The intake manifold has a lower row of four helical swirl ports and an upper row of four filler ports with port shutoff. These eight ports are sealed against mating ports in the cylinder head and cylinder head cover by specially shaped O-rings. The helical swirl port is configured to create optimum swirl for efficient combustion; at the same time, the filler port is designed to deliver large volumes of air without affecting the swirl in the cylinder. The intake manifold port shutoff device is controlled by the ECM. For more information, refer to the chapter: Electronic Engine Controls - 2.2L Diesel (303-14 Electronic Engine Controls - 2.2L Diesel, Description and Operation).

Each cylinder receives air through a helical swirl port, and through a filler port when activated. The helical swirl port is always open and directs air from the lower port of the intake manifold into the combustion chamber. The filler port is normally closed and only opens under certain engine operating conditions when commanded by the ECM. The filler port, when open, directs air from the upper port of the intake manifold through curved intake tracts into the combustion chamber. The intake tracts are part of the cylinder head cover casting and connect the upper filler ports of the intake manifold to the machined filler ports of the cylinder head.

At low engine loads, the gas flow is so low that the filler port closes. This causes the gas velocity through the screw port to increase and the swirl in the cylinder to increase to the optimum intensity. To avoid the risk of high gas flow creating excessive swirl, the ECM opens the filler port under high gas flow conditions to maintain a constant optimum swirl throughout the engine operating range.

Disabling the intake manifold ports

Pos.	Spare part number	Name
1	-	Solenoid valve
2	-	Screw swirl port intake manifold
3	-	Vacuum actuator
4	-	Intake manifold filler port
5	-	Rotary damper (4 pcs.)

Port shutoff is accomplished by four butterfly valves mounted on a common shaft inside the intake manifold. Each butterfly valve is located in a corresponding upper filler port of the intake manifold. The common shaft is connected to a vacuum actuator and is actuated by a solenoid valve controlled by the ECM. The vacuum required to shut off the port is supplied by a vacuum pump mounted on the engine.

For more information, refer to the chapter: Engine (303-01B Engine - 2.2L Duratorq - Td4, Description and Operation), Electronic Engine Controls - 2.2L Diesel (303-14 Electronic Engine Controls - 2.2L Diesel, Description and Operation).

Port shut-off (opening of the filler ports) occurs only when the coolant temperature is greater than 10°C and under the following conditions: