DOC AIRBUS | TSM A320FTroubleshoot the Engine after a High (N2) Vibration event
TASK 71-00-00-810-873-A
Troubleshoot the Engine after a High (N2) Vibration event
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 71-00-00-710-133-A ** ON A/C NOT FOR ALL
Subtask 71-00-00-860-087-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:40:54 UTC
Troubleshoot the Engine after a High (N2) Vibration event
1. Possible Causes
- ACTIVE OIL DAMPER VALVE [4076KS]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 71-00-00-810-854-A | Troubleshoot the Engine after a Surge - Forward Thrust event |
| TSM TASK 75-31-00-810-813-A | HPC SVA Master/Slave Actuator Position Error - Track Check Channel A |
| TSM TASK 77-31-00-810-802-A | PHMU CAN Fault |
| TSM TASK 77-32-00-810-824-A | D-Flange Monitoring Failure |
| TSM TASK 77-32-00-810-825-A | P-Flange Monitoring Failure |
| TSM TASK 79-35-00-810-808-A | Chip Detected Alert by ODM |
| AMM 71-00-00-700-802 | Test No. 8 - Vibration analysis (Vibration Survey) |
| AMM 72-00-00-210-812 | General visual Inspection (GVI) of the Engine Exhaust Area |
| AMM 72-00-00-210-813 | General Visual Inspection (GVI) of the Engine Inlet Area |
| AMM 72-00-00-220-802 | Detailed Visual Inspection (DVI) of the Engine Mount Lugs (Engine Removed) |
| AMM 72-35-00-290-801 | Borescope Inspection of the High Pressure Compressor (HPC) Assembly |
| AMM 72-51-00-290-802 | Borescope Inspection of the High Pressure Turbine (HPT) |
| AMM 73-21-00-710-806 | Test No.7 - EEC Operation Test (Self Test) |
| AMM 79-00-00-281-802 | Inspection of the Magnetic Chip Collectors for Oil Contamination |
| AMM 79-21-07-000-801 | Removal of the Active Oil Damper Valve (AODV) |
| AMM 79-21-07-400-801 | Installation of the Active Oil Damper Valve (AODV) |
Subtask 71-00-00-710-133-A ** ON A/C NOT FOR ALL
A. Investigate the Engine after a High (N2) Vibration event
(1) Use this troubleshooting procedure to investigate the engine after a high (N2) vibration event. N1 vibration or N2 vibration is indicated on the flight deck as VIB N2 amber. The highest value between N1 vibration and N2 vibration will be reported as VIB N2. The maintenance messages related to the high (N2) vibration will be set when high N2 vibration is detected by the FADEC.
(2) Use also this procedure to investigate the engine after a N2 vibration event higher than normal values but not over the amber limit.
(3) Look at the Table 1 for additional information how this fault is displayed on the flight deck.
Table 1 - Vibration: Flight Deck Indicated vs Actual
(4) Look at the engine data to see oil temperature was high when the N2 vibration was high.
(a) If there is a report of high oil temperature along with high N2 vibration, remove and replace the engine.
(5) Using the Multipurpose Control and Display Unit (MCDU) test the FADEC system for any recorded faults AMM 73-21-00-710-806.
(6) Any Electronic Engine Control (EEC) monitored faults are transmitted to the aircraft Centralized Fault Display Interface Unit (CFDIU). The MCDU allows interactive dialog with the EEC. Use the MCDU to review the previous flight leg fault information, scheduled maintenance fault information and ground fault information. If there are any faults reported troubleshoot them first.
4. Fault Isolation(1) Use this troubleshooting procedure to investigate the engine after a high (N2) vibration event. N1 vibration or N2 vibration is indicated on the flight deck as VIB N2 amber. The highest value between N1 vibration and N2 vibration will be reported as VIB N2. The maintenance messages related to the high (N2) vibration will be set when high N2 vibration is detected by the FADEC.
(2) Use also this procedure to investigate the engine after a N2 vibration event higher than normal values but not over the amber limit.
(3) Look at the Table 1 for additional information how this fault is displayed on the flight deck.
Table 1 - Vibration: Flight Deck Indicated vs Actual
| Flight Deck Indication | Actual |
|---|---|
| VIB N1 | NF (Fan Vibration) |
| VIB N2 | N1 (LPC/LPT Vibration) or N2 (HPC/HPT Vibration). Determined by which input has the highest value. |
(a) If there is a report of high oil temperature along with high N2 vibration, remove and replace the engine.
(5) Using the Multipurpose Control and Display Unit (MCDU) test the FADEC system for any recorded faults AMM 73-21-00-710-806.
(6) Any Electronic Engine Control (EEC) monitored faults are transmitted to the aircraft Centralized Fault Display Interface Unit (CFDIU). The MCDU allows interactive dialog with the EEC. Use the MCDU to review the previous flight leg fault information, scheduled maintenance fault information and ground fault information. If there are any faults reported troubleshoot them first.
NOTE: Vibration characteristics are unique to each engine. A short time single high N2 vibration reading is usually not significant unless there is a sudden significant increase in vibration when compared to the initial engine installation vibration levels.
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
Subtask 71-00-00-810-140-A ** ON A/C NOT FOR ALL A. Do the steps that follow:
(1) If the crew alert warning messages related to the engine stall appear, refer to troubleshoot the engine after a surge - forward thrust event (Ref. TSM TASK 71-00-00-810-854).
(2) If the maintenance messages related to the High Pressure Compressor (HPC) Stator Vane Actuator (SVA) primary failure appear with the ECAM warning for engine compressor vane thrust limited, refer to HPC SVA master/slave actuator position error - track check (Ref. TSM TASK 75-31-00-810-813).
(3) If the maintenance messages related to the oil debris overlimit detected by Oil Debris Monitoring (ODM) appear with the ECAM warning for engine oil chip detected, refer to chip detected alert by ODM (Ref. TSM TASK 79-35-00-810-808).
(4) If the maintenance messages related to the forward flange vibration sensor appear with amber crosses on the vibration display, refer to D-flange monitoring failure (Ref. TSM TASK 77-32-00-810-824).
(5) If the maintenance messages related to the aft flange vibration sensor appear with amber crosses on the vibration display, refer to P-flange monitoring failure (Ref. TSM TASK 77-32-00-810-825).
(6) If the maintenance messages related to the Power Health Monitoring Unit (PHMU) CAN Bus failure appear with the ECAM warning for engine minor fault and amber crosses on the vibration display, refer to PHMU CAN fault (Ref. TSM TASK 77-31-00-810-802).
(7) Visually inspect the engine inlet area AMM 72-00-00-210-813.
(8) If you find indications of Foreign Object Damage (FOD) visually inspect the HPC bleed valve discharge area for evidence of metallic debris.
(a) If you find metallic debris, remove the engine from service.
(9) If you do not find any problems, visually inspect the engine exhaust area AMM 72-00-00-210-812.
(a) If you find metallic debris remove the engine from service.
(10) If you do not find any problems, inspect to make sure that the engine external hardware is secure including the engine-mounts and the engine vibration monitoring hardware AMM 72-00-00-220-802.
(11) If you do not find any problems, visually inspect the magnetic chip collectors for oil system contamination AMM 79-00-00-281-802.
(a) If there are indications of metal particles remove the engine from service.
(12) If you do not find any problems, inspect the HPC AMM 72-35-00-290-801.
(13) If you do not find any problems, inspect the High Pressure Turbine (HPT) AMM 72-51-00-290-802.
(14) If you do not find any problems, do a vibration survey AMM 71-00-00-700-802.
(15) If the vibration survey shows N2 vibration above limits when N2 speed was between 68 percent and 90 percent N2 and there is no report of oil debris over limit detected by the ODM, replace ACTIVE OIL DAMPER VALVE [4076KS] AMM 79-21-07-000-801 and AMM 79-21-07-400-801.
(16) If the vibration survey continues to show N2 vibration above limits it may indicate other engine internal distress, remove the engine from service.
5. Close-up(1) If the crew alert warning messages related to the engine stall appear, refer to troubleshoot the engine after a surge - forward thrust event (Ref. TSM TASK 71-00-00-810-854).
(2) If the maintenance messages related to the High Pressure Compressor (HPC) Stator Vane Actuator (SVA) primary failure appear with the ECAM warning for engine compressor vane thrust limited, refer to HPC SVA master/slave actuator position error - track check (Ref. TSM TASK 75-31-00-810-813).
(3) If the maintenance messages related to the oil debris overlimit detected by Oil Debris Monitoring (ODM) appear with the ECAM warning for engine oil chip detected, refer to chip detected alert by ODM (Ref. TSM TASK 79-35-00-810-808).
(4) If the maintenance messages related to the forward flange vibration sensor appear with amber crosses on the vibration display, refer to D-flange monitoring failure (Ref. TSM TASK 77-32-00-810-824).
(5) If the maintenance messages related to the aft flange vibration sensor appear with amber crosses on the vibration display, refer to P-flange monitoring failure (Ref. TSM TASK 77-32-00-810-825).
(6) If the maintenance messages related to the Power Health Monitoring Unit (PHMU) CAN Bus failure appear with the ECAM warning for engine minor fault and amber crosses on the vibration display, refer to PHMU CAN fault (Ref. TSM TASK 77-31-00-810-802).
(7) Visually inspect the engine inlet area AMM 72-00-00-210-813.
(8) If you find indications of Foreign Object Damage (FOD) visually inspect the HPC bleed valve discharge area for evidence of metallic debris.
(a) If you find metallic debris, remove the engine from service.
(9) If you do not find any problems, visually inspect the engine exhaust area AMM 72-00-00-210-812.
(a) If you find metallic debris remove the engine from service.
(10) If you do not find any problems, inspect to make sure that the engine external hardware is secure including the engine-mounts and the engine vibration monitoring hardware AMM 72-00-00-220-802.
(11) If you do not find any problems, visually inspect the magnetic chip collectors for oil system contamination AMM 79-00-00-281-802.
(a) If there are indications of metal particles remove the engine from service.
(12) If you do not find any problems, inspect the HPC AMM 72-35-00-290-801.
(13) If you do not find any problems, inspect the High Pressure Turbine (HPT) AMM 72-51-00-290-802.
(14) If you do not find any problems, do a vibration survey AMM 71-00-00-700-802.
(15) If the vibration survey shows N2 vibration above limits when N2 speed was between 68 percent and 90 percent N2 and there is no report of oil debris over limit detected by the ODM, replace ACTIVE OIL DAMPER VALVE [4076KS] AMM 79-21-07-000-801 and AMM 79-21-07-400-801.
(16) If the vibration survey continues to show N2 vibration above limits it may indicate other engine internal distress, remove the engine from service.
Subtask 71-00-00-860-087-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(1) Make sure that the work area is clean and clear of tools and other items.