1. Wastegate Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Engine Oil Pressure Too Low Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Linkage Binding - Correct Cause of Binding Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Bearings Tight (Carbon Deposits) - Clean and Lubricate with Mouse Milk Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Binding - Function Check Using Shop Air Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Stuck Open Or Closed - Verify Valve Housing Is Not Warped Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Inadequate Engine Oil Flow - Remove Restriction or Replace Line As Needed Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Inlet Port Obstructed - Clear Orifice or Capillary Tube In Port, Or Replace Damaged Capillary Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
2. Controller Not Functioning Properly
| Corrective Action(s) |
|---|
| Verify settings IAW Engine and/or Airframe POH Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
3. Pressure Relief Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Recalibrate Pressure Relief Valve Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
1. Wastegate Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Engine Oil Pressure Too Low Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Linkage Binding - Correct Cause of Binding Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Bearings Tight (Carbon Deposits) - Clean and Lubricate with Mouse Milk Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Binding - Function Check Using Shop Air Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve stuck open or closed - Verify Valve Housing Is Not Warped Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Inadequate Engine Oil Flow - Remove Restriction or Replace Line As Needed Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Inlet Port Obstructed - Clear Orifice or Capillary Tube In Port, Or Replace Damaged Capillary Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
2. Turbocharger Not Functioning Properly
| Corrective Action(s) |
|---|
| Perform Visual inspection of the Compressor and Turbine wheels for Foreign Object Damage, Rubbing, and Axial / Radial Play Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
3. Controller Not Functioning Properly
| Corrective Action(s) |
|---|
| Recalibrate Controller Assembly Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
4. Pressure Relief Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Recalibrate Pressure Relief Valve Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
1. Wastegate Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Engine Oil Pressure Too Low Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Linkage Binding - Correct Cause of Binding Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Bearings Tight (Carbon Deposits) - Clean and Lubricate with Mouse Milk Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Binding - Function Check Using Shop Air Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve stuck open or closed - Verify Valve Housing Is Not Warped Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Inadequate Engine Oil Flow - Remove Restriction or Replace Line As Needed Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Inlet Port Obstructed - Clear Orifice or Capillary Tube In Port, Or Replace Damaged Capillary Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
2. Controller Not Functioning Properly
| Corrective Action(s) |
|---|
| Verify settings IAW Engine and/or Airframe POH Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Recalibrate Controller Assembly Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
3. Turbocharger Not Functioning Properly
| Corrective Action(s) |
|---|
| Perform Visual inspection of the Compressor and Turbine wheels for Foreign Object Damage, Rubbing, and Axial / Radial Play Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
4. Pressure Relief Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Recalibrate Pressure Relief Valve Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
1. Wastegate Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Engine Oil Pressure Too Low Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Linkage Binding - Correct Cause of Binding Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Bearings Tight (Carbon Deposits) - Clean and Lubricate with Mouse Milk Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve Binding - Function Check Using Shop Air Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Butterfly Valve stuck open or closed - Verify Valve Housing Is Not Warped Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
| Inadequate Engine Oil Flow - Remove Restriction or Replace Line As Needed Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Actuator Inlet Port Obstructed - Clear Orifice or Capillary Tube In Port, Or Replace Damaged Capillary Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
2. Turbocharger Not Functioning Properly
| Corrective Action(s) |
|---|
| Perform Visual inspection of the Compressor and Turbine wheels for Foreign Object Damage, Rubbing, and Axial / Radial Play Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
3. Controller Not Functioning Properly
| Corrective Action(s) |
|---|
| Verify settings IAW Engine and/or Airframe POH Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Recalibrate Controller Assembly Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
4. Pressure Relief Valve Not Functioning Properly
| Corrective Action(s) |
|---|
| Recalibrate Pressure Relief Valve Refer to Current Version Of Overhaul / Maintenance Manual 400999-0000 |
5. Engine Intercooler Vanes Clogged
| Corrective Action(s) |
|---|
| Visual Inspect For Improper Airflow Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
1. Turbocharger Oil Leakage
| Corrective Action(s) |
|---|
| Visual Inspect the Oil Inlet Check Valve For Proper Installation, Damage, and Clear Of Debris Refer To Current Version Of The Engine Manufacturer Maintenance Manual Or Service Information |
| Pressure Check The Oil Inlet Check Valve Refer To Current Version Of The Engine Manufacturer Maintenance Manual Or Service Information |
| Visual Inspect the Oil Outlet Check Valve For Proper Installation, Damage, and Clear Of Debris Refer To Current Version Of The Engine Manufacturer Maintenance Manual Or Service Information |
| Pressure Check The Oil Outlet Check Valve Refer To Current Version Of The Engine Manufacturer Maintenance Manual Or Service Information |
| Visual inspection the oil line installations for kinks and slope Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
1. Turbocharger Oil Leakage
| Corrective Action(s) |
|---|
| New Installation (Oil Residue) Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
| Engine Bypassing Turbine Wheel Assembly Piston Rings Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
| Failed Engine - Perform Engine Compression Check Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
1. Foreign Object Damage from Air inlets, Air Filter, Alternate Air system
| Corrective Action(s) |
|---|
| Repair, Overhaul, Replace Turbocharger Inspect Intercooler Borescope Engine Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
1. Foreign Object Damage, Failed Engine Exhaust System
| Corrective Action(s) |
|---|
| Repair, Overhaul, Replace Turbocharger Inspect Engine Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
1. Restriction in Air filter or Duct Between Air Cleaner and Turbocharger
| Corrective Action(s) |
|---|
| Remove Restriction or Replace Parts As Needed Refer To Current Version Of The Airframe Manufacturer Maintenance Manual |
2. Heavy Carbon Buildup Behind Turbine Wheel
| Corrective Action(s) |
|---|
| Perform Visual inspection of the Compressor and Turbine wheels for Foreign Object Damage, Rubbing, and Axial / Radial Play Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
3. Heavy Sludge or Coking in Center Housing
| Corrective Action(s) |
|---|
| Perform Visual inspection of the Center Housing Oil Outlet Port Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
1. Turbocharger Leakage at Compressor Side
| Corrective Action(s) |
|---|
| Air Cleaner Element Clogged Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Restriction or Faulty Check Valve In Turbocharger, Oil Drain Line Remove Restriction or Replace Parts As Needed Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Malfunction In Oil Scavenge Pump Or Drain Sump Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Restriction in Engine Crankcase Breather Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Excessive Operation at Low Manifold Pressure Setting |
1. Turbocharger Leakage at Turbine Side
| Corrective Action(s) |
|---|
| Restriction or Faulty Check Valve in Turbocharger, Oil Drain Line Remove Restriction or Replace Parts As Needed |
| Heavy Sludge or Coking in Center Housing Perform Visual inspection of the Center Housing Oil Outlet Port Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 |
| Restriction in Engine Crankcase Breathe Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
| Malfunction In Oil Scavenge Pump Or Drain Sump Refer To Current Version Of The Engine Manufacturer Maintenance Manual |
1. Compressor Wheel Damaged by Foreign Object
| Corrective Action(s) |
|---|
| Clean and Repair Air Induction System As Required Refer To Current Version Of The Airframe Manufacturer Maintenance Manual Repair, Overhaul or Replace Turbocharger |
2. Turbine Wheel Damaged by Foreign Object
| Corrective Action(s) |
|---|
| Inspect Engine Cylinders And Exhaust System Refer To Current Version Of The Engine Manufacturer Maintenance Manual Repair, Overhaul or Replace Turbocharger |
3. Heavy Carbon Buildup Behind Turbine Wheel
| Corrective Action(s) |
|---|
| Perform Visual Inspection For Axial / Radial Play Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 Repair, Overhaul or Replace Turbocharger |
4. Heavy Sludge or Coking in Center Housing
| Corrective Action(s) |
|---|
| Perform Visual inspection of the Center Housing Oil Outlet Port Refer to Current Version Of Overhaul / Maintenance Manual 400600-0000 Repair, Overhaul or Replace Turbocharger |
Copyright © 2026 Hartzell Engine Technologies LLC. All rights reserved.