Land Rover Discovery: Fuel Charging and Controls - Turbocharger - Ingenium i4 2.0l Diesel / Description and Operation

COMPONENT LOCATION

1. Turbocharger
2. Low Pressure EGR valve

OVERVIEW

The turbocharger is a variable geometry turbocharger (VGT) .

The turbocharger consists of two elements; a turbine and a compressor.

These elements are enclosed separately in cast housings and mounted on a common shaft, which rotates in a single semi-floating bearing.

Turbocharger cooling is achieved using engine oil to allow it to maintain the optimum operating temperature and protect the bearings from overheating.

DESCRIPTION

TURBOCHARGER - INGENIUM I4 2.0L DIESEL

1. Turbocharger
2. Turbocharger oil feed
3. Oil filter
4. Turbocharger oil drain

1. Intake air from air filter
2. Compressed air to charge air cooler
3. Exhaust gas inlet
4. Exhaust gas outlet

The turbocharger is attached to the exhaust manifold.

The intake to the turbocharger incorporates a turbine by-pass control valve, controlled by an actuator.

The turbine by-pass control actuator is controlled by the engine control module (ECM).

A sensor on the turbine by-pass control actuator produces a signal for the ECM to indicate the position of the control valve.

The variable geometry turbocharger vane actuator in the VGT is controlled by a signal from the ECM, the ECM also provides a 5V supply to the actuator and motor supplies.

The VGT makes it possible to vary the exhaust gas flow of the turbine, dependent on engine operation. This improves the power transfer to the turbine wheel and compressor, particularly at low engine speeds, thus increasing the boost pressure.

The guide vanes are opened progressively as the engine speed increases so that the power transfer always remains in balance with the required charger speed and the required boost pressure level.

Variable vanes facilitate better use of the exhaust gas energy, this further improves the efficiency of the turbocharger and the engine.

A heatshield is installed over the turbocharger and exhaust manifold to protect other components, and to prevent accidental contact with the hot exhaust components.

TURBOCHARGER - COOLING AND LUBRICATION

The turbocharger receives an oil supply for lubrication and cooling purposes.

The oil for the turbocharger comes from the oil filter assembly.

The rapid acceleration and deceleration response demands of the turbocharger rely greatly on a steady flow of clean oil. The oil supplied from the engine's lubrication system provides lubrication to the turbocharger's spindle and bearings, while also acting as a coolant for the turbocharger center housing.

To maintain the life expectancy of the turbocharger, it is essential that the oil has a free-flow through the turbocharger and unrestricted return to the engine's oil pan. It is therefore imperative that the engine oil is replenished at regular service intervals with the recommended quality and quantity of oil.

OPERATION

TURBOCHARGER

The turbocharger is an exhaust-driven centrifugal air compressor which increases power output by supplying compressed air to the engine. The turbine wheel of the turbocharger uses the engine's exhaust gasses to drive the compressor wheel.

The compressor wheel draws in fresh air which is compressed and delivered through a charge air cooler to the throttle body.

The air intake to the turbocharger receives air from the EGR system.

For additional information, refer to: Engine Emission Control (303-08B Engine Emission Control - INGENIUM I4 2.0L Diesel, Description and Operation).

By turbocharging the engine, the pressure and density of the air entering the cylinders is increased, and therefore so is the amount of oxygen. This enables a greater quantity of fuel to be injected, thus increasing the engine's power output, improving fuel consumption and the ability to maintain power at higher altitudes.

The internal components are oil cooled. Engine oil is circulated through the center housing which acts as a heat barrier between the "hot" turbine and the "cold" compressor. The bearing is a sleeve type and is lubricated by engine oil. Oil is circulated to the turbocharger center housing and returned to the sump through an oil drain to the cylinder block.

The charge air cooler (air to water type) is used to increase the density of air as it flows from the turbocharger compressor to the intake manifold.

Compression of the charge air by the turbocharger raises the temperature of the air. This generation of heat further decreases the charge air density, and consequently less oxygen is able to enter the cylinders, reducing the engines power. To overcome this, the air is routed through the charge air cooler before it enters the engine; the temperature is reduced by transferring the heat to atmosphere. Cooling of the intake air also helps to reduce engine emissions by limiting nitrogen oxides (NOx) production.

For additional information, refer to: Intake Air Distribution and Filtering (303-12B Intake Air Distribution and Filtering - INGENIUM I4 2.0L Diesel, Description and Operation).

Fuel Charging and Controls - Turbocharger - Ingenium i4 2.0l Diesel Diagnosis and Testing

PRINCIPLES OF OPERATION

For a detailed description of the Turbocharger, refer to the relevant Description and Operation section in the workshop manual. REFER to: Turbocharger (303-04D Fuel Charging and Controls - Turbocharger - INGENIUM I4 2.0L Diesel, Description and Operation).

INSPECTION AND VERIFICATION

WARNINGS:

• The following tests may involve working in close proximity to hot components. Make sure adequate protection is used. Failure to follow this instruction may result in personal injury.
• The turbocharger can continue to rotate after the engine has stopped. Do not attempt to check the turbocharger until one minute has elapsed since the engine was switched off. Failure to follow this instruction may result in personal injury.

CAUTION:

Diagnosis by substitution from a donor vehicle is NOT acceptable.

Substitution of control modules does not guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle.

NOTES:

• If a control module or a component is suspect and the vehicle remains under manufacturer warranty, refer to the Warranty Policy and Procedures manual, or determine if any prior approval programme is in operation, prior to the installation of a new module/component.
• When performing voltage or resistance tests, always use a digital multimeter accurate to three decimal places, and with an up-todate calibration certificate. When testing resistance always take the resistance of the digital multimeter leads into account.
• Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

1. Verify the customer concern
2. Visually inspect for obvious signs of damage and system integrity

Visual Inspection

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step
4. If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index
5. Check DDW for open campaigns. Refer to the corresponding bulletins and SSMs which may be valid for the specific customer complaint and carry out the recommendations as required

SYMPTOM CHART

SYMPTOM:

Engine performance poor

POSSIBLE CAUSES:

• Engine system fault
• Intake pipe restricted/blocked
• Charge air cooler hoses leaking
• Charge air cooler leaking
• Variable geometry turbine vane actuator detached/seized
• Turbocharger failure
• General engine condition

ACTION:

• Using the Jaguar Land Rover approved diagnostic equipment, check the powertrain control module for related DTCs and refer to the relevant DTC index
• Check the intake pipe for restrictions and blockages. Rectify as necessary
• Check the charge air cooler hoses for leaks.

  Rectify as necessary

• Check the charge air cooler for leaks. Rectify as necessary
• Check the integrity of the variable geometry turbine vane actuator. Rectify as necessary
• Check the integrity of the turbocharger. Rectify as necessary
• Check the engine condition, compressions, etc.

  Rectify as necessary

DTC INDEX

For a list of Diagnostic Trouble Codes (DTCs) that could be logged on this vehicle, please refer to Section 100-00. REFER to: Diagnostic Trouble Code Index - INGENIUM I4 2.0L Diesel, DTC: Engine Control Module (ECM) B10A2-07 to P034B-76 (100-00 General Information, Description and Operation).

Fuel Charging and Controls - Turbocharger - Ingenium i4 2.0l Diesel Specifications

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