NOTE: It is normal for a small amount of combustion chamber gases to leak into the engine crankcase. This gas is purged into the air intake system by the Positive Crankcase Ventilation (PCV) system, which has a built-in oil separator. Along with the gases purged from the crankcase, some engine oil in vapor form (this engine oil also helps extend the life of the valve seats) enters the air intake system. This means that oil will collect inside the air intake components and turbocharger. This is not a sign of a defective turbocharger oil seal. The turbocharger oil seal will not fail unless the bearings fail first, causing noise and seizure of the turbocharger compressor. Do not install a new turbocharger due to oil leakage into the turbocharger or air intake system components. If a leak is found in the oil supply and return lines or their connections, find and repair the cause. Do not install a new turbocharger due to an oil leak.
1. Check the customer complaint.
2. Perform a visual inspection for obvious signs of mechanical damage.
Visual inspection table
|
Mechanical factors |
Electrical factors |
|
Oil leak(s) |
Wiring harness |
|
Air filter element |
Electrical connector(s) |
|
Air filter outlet pipe |
Vane Adjustment Solenoid Valve - 115hp Diesel Vehicles. |
|
Air filter inlet pipe |
RSM |
|
Turbocharger feed or return oil lines |
|
|
Turbine Bypass Control Valve - 75hp or 90hp Diesel Vehicles. |
|
|
Vacuum Diaphragm Block - 115 HP Diesel Vehicles. |
|
|
Turbocharger housing |
3. If an obvious cause for the problem you have identified or the problem described by the client is found, eliminate this cause (if possible) before proceeding with further actions.
4. If the cause is not visually obvious, check the malfunction symptom and refer to the Malfunction Symptom Table.
Table of signs of malfunction
NOTE: The vacuum diaphragm unit is an integral part of the turbocharger and cannot be replaced or adjusted separately.
|
State |
Possible Causes |
Action |
|
•Blue smoke accompanied by increased turbocharger noise |
•The turbocharger compressor touches the walls of the housing. •The turbocharger turbine touches the walls of the housing. •Turbocharger bearings and oil seal(s). •The turbocharger oil supply line is clogged or damaged. |
• Proceed to PINPOINT TEST A. |
|
•Blue smoke, not accompanied by increased turbocharger noise |
•Clogging or damage to the turbocharger return oil line. |
• Proceed to PINPOINT TEST B. |
|
•Poor engine performance - vehicles with 75hp or 90hp diesel engines. |
•Turbine bypass control valve vacuum line(s). |
•CHECK that all vacuum lines are installed and that there are no signs of air leaks. Make any necessary repairs. |
|
•Unauthorized adjustment of the turbine bypass control valve drive stem. |
•The turbocharger boost pressure is set at the factory and is not adjustable. CHECK the paint seal on the vacuum diaphragm block actuator rod for a broken seal. If the seal is broken, INSTALL a new turbocharger. For additional information, refer to Turbocharger - 75hp or 90hp Diesel Vehicles in this section. |
|
|
•Turbine bypass control valve actuator stem. |
•CHECK the turbine bypass control valve actuator stem for freedom of movement. If the turbine bypass control valve actuator stem does not move freely. CHECK for signs of damage or signs of foreign material. Repair as necessary. • Proceed to PINPOINT TEST C. |
|
|
•Poor engine performance - vehicles with 115 hp diesel engine. |
•Vacuum lines of the vacuum diaphragm block. |
•CHECK that all vacuum lines are installed and that there are no signs of air leaks. Make any necessary repairs. |
|
•Unauthorized adjustment of the drive rod of the vacuum diaphragm block. |
•The turbocharger boost pressure is set at the factory and is not adjustable. CHECK the paint seal on the vacuum diaphragm block actuator rod for a broken seal. If the seal is broken, INSTALL a new turbocharger. For more information, refer to Turbocharger - 115hp Diesel Vehicles in this section. |
|
|
•Drive rod of the vacuum diaphragm block. |
•CHECK the vacuum diaphragm block actuator rod for free movement. If the vacuum diaphragm block actuator rod does not move freely. CHECK for signs of damage or signs of foreign material. Repair as necessary. • Proceed to PINPOINT TEST D. |