Turbocharger Repair Procedures

Removal and Installation

1. Remove the turbocharger manifold. (Refer to Intake and Exhaust System - "Turbocharger and Exhaust Manifold")

Inspection on Vehicle

Turbocharger Diagnosis Chart

1. 1
   Check the turbocharger fit on the connecting part (or after machining).

   • Make sure the gasket is installed correctly.
   • Check that the mounting bolts (or nuts) are tightened correctly.
   • Check for gas leaks.
   • Check for damage such as cracks or chips.

   Gas leakage caused by a missing gasket or improperly tightened mounting bolts (or nuts) can cause abnormal engine noise. If the cause of the problem is found, tighten the mounting bolts (or nuts) to the specified torque, or replace the gasket or damaged parts with new parts as necessary.
2. 2
   Check the exhaust manifold and cylinder head assembly.

   • Make sure the gasket is installed correctly.
   • Check that the mounting bolts (or nuts) are tightened correctly.
   • Check for gas leaks.

   Gas leakage caused by a missing gasket or improperly tightened mounting bolts (or nuts) can cause abnormal engine noise. If the cause of the problem is found, tighten the mounting bolts (or nuts) to the specified torque, or install a new gasket if necessary.
3. 3
   Check the turbocharger oil supply pipe and hose, and the oil drain pipe and hose.

   • Make sure the gasket is installed correctly.
   • Check that the mounting bolts are tightened correctly.
   • Check that the clips are in place.
   • Check that the oil pipes and hoses are not damaged (kinked, crushed, torn, or cracked).

   If a gas leak occurs when the gasket was not installed or the mounting bolts were improperly tightened, oil leakage may result. If the oil supply pipe and hose are damaged, engine oil is not supplied sufficiently to the turbocharger, which may damage the turbocharger. If the oil drain pipe and hose are damaged or clogged, engine oil is not drained smoothly, which may cause oil leakage from the turbocharger. If the cause of the problem is found, tighten the mounting bolts (or nuts) to the specified torque, or replace the gasket or damaged parts with new parts as necessary.
4. 4
   Check for oil leaks between the center housing and the compressor housing.

   • Check that the mounting bolts are tightened correctly.
   • Check for oil leaks.

   Damage to the O-ring (gasket) between the center housing and the compressor housing may cause oil leakage. If oil leakage is found, replace the turbocharger with a new one.
5. 5
   Check the turbocharger actuator.

   • Electronic actuator: Check the actuator rod stroke when the actuator operating force is applied by the GRS. (Refer to the Trouble Code Troubleshooting manual.)

     

   A damaged turbocharger actuator may cause lack of engine power and poor acceleration. If the actuator rod does not move, replace the turbocharger with a new one.
6. 6
   Check the turbocharger compressor wheel.

   • Check that the compressor wheel is not damaged (bent or deformed).
   • Check that the compressor wheel rotates smoothly.

     

   A damaged compressor wheel may cause abnormal turbocharger noise and poor acceleration. If the compressor wheel is damaged or deformed, replace the turbocharger with a new one.
7. 7
   Check the turbocharger turbine wheel.

   • Check that the turbine wheel is not damaged.
   • Check that the turbine wheel rotates smoothly.

     

   A damaged turbine wheel may cause abnormal turbocharger noise and poor acceleration. If the turbine wheel is damaged or deformed, replace the turbocharger with a new one.
8. 8
   Check the blow-by hose. (Refer to Group FL.)

   • Check that the breather hose is not damaged (kinked or clogged).
   • Check that the PCV (Positive Crankcase Ventilation) valve is not clogged.

   If the breather hose is kinked or clogged, internal engine pressure increases and engine oil is not supplied evenly to the turbocharger, causing turbocharger damage and oil leakage. If the cause of the problem is found, replace the breather hose or related parts with new ones.
9. 9
   Check the intake hose connected to the turbocharger.

   • Check that the intake air hose is not damaged (kinked, crushed, loose, or torn).

   If the cross-section of the intake air hose is reduced when it is bent or compressed, the intake air supplied to the turbocharger decreases and the pressure in front of the turbocharger drops, causing turbocharger damage or oil leakage. If the intake hose is loose or torn, foreign matter may enter the turbocharger and cause damage. If the intake air hose is damaged, replace it with a new one.
10. 10
    Check the air filter.

    • Check the air filter for contamination.
    • Check the air filter for water intrusion.
    • Check that the air filter cover is not dirty.
    • Check that the air filter is a genuine part.

    If the air filter is excessively wet or dirty, or if a non-genuine part is used, the intake air supplied to the turbocharger decreases and the pressure in front of the turbocharger drops, causing turbocharger damage and oil leakage. If the air filter is excessively wet or dirty, replace it with a new one.
11. 11
    Check the intercooler hoses and pipes.

    • Make sure that the intercooler pipes and hoses are connected correctly.
    • Inspect the intercooler hoses and pipes for damage (kinks, loose connections or cracks).
    • Inspect the intercooler pipes for damage such as cracks.
    • Check that the clamps are in place.

    If the intercooler hoses and pipes are damaged or disconnected, oil leakage from the hoses may occur. Also, the pipes and turbocharger may exceed the allowable speed, which may damage the turbocharger. If the intercooler hoses and tubes are damaged, replace them with new ones.
12. 12
    Inspect the intercooler.

    • Inspect the intercooler hoses and tanks for damage (oil leakage or cracks).

    If the intercooler is damaged, the turbocharger may exceed the allowable speed, which will damage the turbocharger. If the intercooler is damaged, replace it with a new one.
13. 13
    Check the engine oil.

    • Check the engine oil level.
    • Check the engine oil for discoloration, water contamination and degradation of engine oil viscosity.
    • Check the engine oil quality.

    If the engine oil level is low, the engine oil supply to the turbocharger decreases, and the turbocharger bearings may seize due to insufficient lubrication and cooling. If the cause of the problem is found, add engine oil or replace it.
14. 14
    Check the engine oil pressure.

    • Engine oil pressure: Check the oil pressure with a gauge after removing the oil pressure sensor from the cylinder block.
    • If the engine oil level is low, check the engine oil strainer in the oil pan. Then check for gas leakage from the injectors if foreign material has accumulated on the oil filter.

    If the engine oil level is low, the engine oil supply to the turbocharger decreases, and the turbocharger bearings may seize due to insufficient lubrication and cooling. If the cause of the problem is found, add engine oil or replace it. If foreign material has accumulated on the oil screen, clean it and replace the injector washer with a new one after checking for gas leakage from the injectors. Check the parts related to the engine oil, such as the oil pump, if necessary.
15. 15
    Check the injectors, sensors, etc. (Refer to Engine Control Module / Fuel System)

    • Check that the injectors operate correctly.
    • Check that sensors such as the Mass Air Flow Sensor (MAFS), Intake Air Temperature Sensor (IATS) and Boost Pressure Sensor (BPS) operate correctly.

    Incorrect operation of the injectors, sensors, EGR valve, etc. may result in reduced engine power. If the cause of the problem is found, replace the relevant parts.