| Diagnosis and Testing Special Tool(s) | | Boost Pressure Gauge 310 - 020 (23 - 021) | | | Hand Vacuum/Pressure Pump 416 - D001 (23 - 036A) | General Equipment Worldwide Diagnostic System (WDS) (418-F224) Principles of Operation - Vehicles with fix vane turbocharger The turbocharger is governed by a wastegate control valve. The wastegate control valve redirects some of the exhaust gas past the turbine and therefore acts as a governor. The wastegate control valve is preset during manufacture and must not be tampered with. Principles of Operation - Vehicles with variable vane turbocharger The turbocharger is designed to improve engine induction and engine performance. The list below details the concerns relating to turbocharger performance. - High engine speed produces excessive turbine speed and therefore creates excessive turbocharger boost pressure.
- Low engine speed does not produce sufficient turbine speed and therefore not enough turbocharger boost pressure is achieved.
The variable vane turbocharger does not have a wastegate control valve. Instead, it has variable turbocharger vanes which are located in the turbocharger turbine housing. The turbocharger vanes act as the control for the turbocharger boost pressure. The variable turbocharger produces its full turbocharger boost pressure over the entire engine speed range, not just at high engine speed. This is achieved through the adjustment of the vanes and the resulting change in the velocity of the exhaust gas. The speed of flow of the stream of exhaust gas is increased independent of engine speed by varying the intake cross section in front of the turbocharger turbine. The variable vanes are controlled by the powertrain control module (PCM). A duty cycle signal from the PCM, controls a vacuum supply to the turbocharger vacuum diaphragm unit using a solenoid valve. Regulation at Low Engine Speed 1 - Vane adjustment solenoid valve At low engine speeds the PCM actuates the vane adjustment solenoid valve to enable a vacuum to be applied. The vacuum diaphragm unit moves the adjusting ring so that the vanes are set at a shallow angle. The reduced intake cross section this creates for the stream of exhaust gas increases the exhaust gas velocity allowing the turbocharger boost pressure to build up rapidly and easily at low engine speeds. Regulation at Moderate Engine Speed 1 - Vane adjustment solenoid valve As the engine speed increases and the quantity of exhaust gas increases as a result, the vane adjustment solenoid valve adjusts the vacuum level within the vacuum diaphragm unit. The vacuum diaphragm unit moves the adjusting ring so that the vanes are set at a steeper angle. The steeper angle opens the intake cross section effectively reducing the gas flow and turbine speed while maintaining constant turbocharger boost pressure. Regulation at Maximum Engine Speed 1 - Vane adjustment solenoid valve As the engine speed increases the intake cross section in front of the turbocharger turbine is continuously enlarged. The turbine speed and hence the quantity of the air supplied to the engine, is adjusted to suit the engine speed. This means that the turbocharger boost pressure remains optimized over all engine speeds. The maximum position of the turbocharger vanes (maximum opening cross section) is also an emergency position e.g. in the event of an electrical concern or leak in the vacuum system. Therefore, there is little chance of engine damage due to excessive boost in the event of a turbocharger control concern. Inspection and Verification NOTE:The turbocharger uses engine oil as a lubricant and coolant. Due to the high operating temperatures of the turbocharger and the expansion and contraction of the internal components a proportion of engine oil may enter the air intake system. This is not an indication that the turbocharger oil seal has failed. The turbocharger oil seal will not fail unless the bearings fail first, which will cause the turbocharger to become noisy. Do not install a new turbocharger due to oil inside the turbocharger or the air intake components. If a leak is detected in the supply or return tubes or connections, locate and rectify the source. Do not install a new turbocharger due to an oil leak. - Verify the customer concern.
- Visually inspect for obvious signs of mechanical damage.
Visual Inspection Chart | Mechanical | Electrical | - Oil leak(s)
- Air cleaner element
- Air cleaner outlet pipe
- Air cleaner intake pipe
- Turbocharger oil supply or oil return tube
- Vacuum line(s) - vehicles with variable vane turbocharger
- Vacuum diaphragm unit - vehicles with variable vane turbocharger
- Wastegate control valve - vehicles with fixed vane turbocharger
- Turbocharger housing
| - Wiring harness
- Electrical connector(s)
- Vane adjustment solenoid valve
- PCM
| - If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the cause is not visually evident, verify the symptom and refer to Symptom Chart.
Symptom Chart NOTE:The vacuum diaphragm unit is a fixed part of the turbocharger and cannot be adjusted or renewed. Symptom Chart | Symptom | Possible Sources | Action | | Blue smoke with excessive turbocharger noise | * Turbocharger compressor rubbing on housing walls. * Turbocharger turbine rubbing on housing walls. * Turbocharger bearings and oil seal(s). * Turbocharger oil supply tube blocked or damaged. | * | | Blue smoke without excessive turbocharger noise | * Turbocharger oil return tube blocked or damaged. | * | | Poor engine performance | * Vacuum diaphragm unit vacuum line(s) - vehicles with variable vane turbocharger. | * CHECK all vacuum line(s) are correctly installed with no signs of damage or restrictions. REPAIR as necessary. | | * Unauthorized adjustment of the vacuum diaphragm unit actuator rod - vehicles with variable vane turbocharger. | * The turbocharger vacuum diaphragm unit actuator rod is factory set and must not be adjusted. CHECK the paint seal on the vacuum diaphragm unit actuator rod has not been broken. If the paint seal has been broken, INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
| | * Unauthorized adjustment of the wastegate control valve actuator rod - vehicles with fixed vane turbocharger. | * The wastegate control valve actuator rod is factory set and must not be adjusted. CHECK the paint seal on the wastegate control valve actuator rod has not been broken. If the paint seal has been broken, INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel (75 PS/90 PS) (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
| | * Vacuum diaphragm unit actuator rod - vehicles with variable vane turbocharger. | * Using WDS, obtain the diagnostic trouble codes (DTC's). Run the exhaust gas recirculation (EGR) test and manifold absolute pressure (MAP) test from the guided diagnostic routines. If no faults are found, GO to Pinpoint Test D. | | * Wastegate control valve actuator rod - vehicles with fixed vane turbocharger. | * | Pinpoint Tests | PINPOINT TEST A : BLUE SMOKE WITH EXCESSIVE TURBOCHARGER NOISE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: INSPECT THE TURBOCHARGER ROTOR VANES FOR DAMAGE | | | 1 Disconnect the air cleaner outlet pipe from the turbocharger. | | | 2 Inspect the turbocharger rotor vanes for damage. | | | Is there visible damage to the rotor vanes? Yes No | | A2: CHECK FOR FOREIGN MATERIAL IN THE INTAKE AIR SYSTEM COMPONENTS | | | 1 Check the intake air system components for signs of foreign material. | | | Are there any signs of foreign material? Yes CLEAN the intake air system components. INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel (75 PS/90 PS) (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation) /
Turbocharger - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
TEST the system for normal operation. No | | A3: CHECK THE TURBOCHARGER BEARINGS FOR EXCESSIVE MOVEMENT | NOTE:A small amount of movement in the bearings is normal. | NOTE:The initial rotor rotation of a cold turbocharger may feel rough and uneven but should rotate freely after a few turns. | | | 1 Make sure the turbocharger rotor spins freely within the housing. - 1. With the turbocharger stationary, gently lift the shaft (the shaft will naturally lay in the bottom of the bearings).
- 2. Make sure the rotor spins freely within the housing.
| | | Does the rotor spin freely within the housing? Yes No INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel (75 PS/90 PS) (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation) /
Turbocharger - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
TEST the system for normal operation. | | A4: CHECK THE TURBOCHARGER OIL SUPPLY TUBE FOR BLOCKAGE | | | 1 Vehicles built up to 06/1999, with fixed vane turbocharger. Remove the turbocharger oil supply tube. | | | 2 Vehicles built 06/1999 onwards, with fixed vane turbocharger. Detach the turbocharger oil supply and return tubes. | | | 3 Vehicles with variable vane turbocharger. Remove the turbocharger oil supply tube. | | | 4 Using workshop compressed air and a compressed air nozzle, check the oil supply tube for blockage. | | | Is there any signs of blockage? Yes INSTALL a new turbocharger oil supply tube. INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel (75 PS/90 PS) (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation) /
Turbocharger - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
TEST the system for normal operation. No INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel (75 PS/90 PS) (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation) /
Turbocharger - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
TEST the system for normal operation. | | PINPOINT TEST B : BLUE SMOKE WITHOUT EXCESSIVE TURBOCHARGER NOISE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: CHECK THE TURBOCHARGER OIL RETURN TUBE | | | 1 Vehicles built up to 06/1999 with fixed vane turbocharger. Disconnect the turbocharger oil return tube from the turbocharger. | | | 2 Vehicles built 06/1999 onwards, with fixed vane turbocharger. Disconnect the turbocharger supply and return tubes. | | | 3 Vehicles with variable vane turbocharger. Disconnect the turbocharger return tube. | | | 4 Remove the turbocharger oil return tube. | | | 5 Check the turbocharger oil return tube for a blockage or signs of damage. | | | Is the turbocharger oil return tube OK? Yes GO to Fuel Charging and Controls for further blue smoke diagnostics.
REFER to: Fuel Charging and Controls (303-04C Fuel Charging and Controls - 1.8L Diesel (75 PS/90 PS), Diagnosis and Testing) /
Fuel Charging and Controls (303-04F Fuel Charging and Controls - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection, Diagnosis and Testing).
No INSTALL a new turbocharger oil return pipe. TEST the system for normal operation. | | PINPOINT TEST C : POOR ENGINE PERFORMANCE - VEHICLES WITH FIXED VANE TURBOCHARGER | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK THE WASTEGATE ACTUATOR CONTROL PIPE FOR BLOCKAGE | | | 1 Remove the wastegate actuator control pipe. | | | 2 Using a hand vacuum/pressure pump connect one end to the wastegate actuator control pipe, operate the hand vacuum/pressure pump and observe the reading. | | | Is a reading present? Yes INSTALL a new wastegate actuator control pipe. TEST the system for normal operation. No | | C2: CHECK THE WASTEGATE ACTUATOR DIAPHRAGM FOR LEAKS | | | 1 Connect one end of the wastegate actuator control pipe to the wastegate actuator. | | | 2 Connect the other end of the wastegate control actuator pipe to a hand vacuum/pressure pump. | | | 3 Operate the hand vacuum/pressure pump and observe the reading. | | | Does the pump hold a vacuum? Yes No INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel (75 PS/90 PS) (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
TEST the system for normal operation. | | C3: CHECK THE BOOST PRESSURE | NOTE:The boost pressure is factory set and must not be adjusted. | | | 1 Using a boost pressure gauge and a T connector, connect the gauge between the wastegate control actuator and the turbocharger. | | | 2 Start and run the engine until normal operating temperature is achieved. | | | 3 Raise the engine speed to 3000 rpm and observe the reading. | | | Is the boost pressure more than 0.5 bar? Yes NO fault is indicated with the turbocharger or its control systems. To continue diagnostics.
REFER to: Fuel Charging and Controls (303-04C Fuel Charging and Controls - 1.8L Diesel (75 PS/90 PS), Diagnosis and Testing).
No INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel (75 PS/90 PS) (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
TEST the system for normal operation. | | PINPOINT TEST D : POOR ENGINE PERFORMANCE VEHICLES WITH VARIABLE VANE TURBOCHARGER | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | D1: CHECK THE VACUUM DIAPHRAGM UNIT ACTUATOR ROD MOVEMENT | | | 1 Start the engine. | | | 2 Observe the vane control lever. | | | Does the diaphragm actuator rod travel its maximum distance and the vane control lever reach its stop? Yes No | | D2: CHECK THE TURBOCHARGER BOOST PRESSURE | | | 1 Stop the engine. | | | 2 Disconnect the vacuum line from the vacuum diaphragm unit. | | | 3 Install the special tool to the vacuum diaphragm unit. | | | 4 Using WDS datalogger, PCM function, select the signals for RPM# and MAP. | | | 5 Start the engine. | | | 6 Using the output state control option (RPM#) on WDS, raise the engine speed to between 3400 rpm and 3500 rpm. | | | 7 Operate the special tool until the vane control lever reaches its stop. | | | 8 Observe the reading of the WDS datalogger MAP signal. | | | Is the MAP reading a minimum of 1.95 bar? Yes NO fault is indicated with the turbocharger or its control systems. To continue diagnostics.
REFER to: Fuel Charging and Controls (303-04F Fuel Charging and Controls - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection, Diagnosis and Testing).
No CHECK the exhaust gas recirculation (EGR) valve for partial obstruction or sticking open. REPAIR or INSTALL new as required. TEST the system for normal operation.CHECK the air induction system for leaks or blockages. REPAIR or INSTALL new as required. TEST the system for normal operation.If no fault is found with the EGR valve or air intake system, INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
| | D3: CHECK THE VACUUM DIAPHRAGM UNIT | | | 1 Stop the engine. | | | 2 Disconnect the vacuum line from the vacuum diaphragm unit. | | | 3 Install the special tool to the vacuum diaphragm unit. | | | Does the diaphragm actuator rod travel its maximum distance and the vane control lever reach its stop? Yes CHECK the vacuum diaphragm unit vacuum control pipe for leaks or restriction. INSTALL a new pipe as required. If no fault is found, continue the diagnostic using WDS. No INSTALL a new turbocharger.
REFER to: Turbocharger - 1.8L Diesel, Vehicles With: Common Rail Fuel Injection (303-04D Fuel Charging and Controls - Turbocharger, Removal and Installation).
TEST the system for normal operation. | | |
