W DOC AIRBUS | TSM A320F

The EGT of one engine is significantly higher than on the other engine

TASK 77-00-00-810-855-A
The EGT of one engine is significantly higher than on the other engine

1. Possible Causes
  • VBV system
  • VSV system
  • pack flow control valves
  • IP check valve
  • T495 thermocouple
  • harness CJ13
  • ECU [4000KS]
  • harness J13
  • Fuel nozzles
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 21-51-00-810-807-A
FCV 1 (FCU 1) Regulation/Indication Fault
TSM TASK 21-51-00-810-808-A
FCV 2 (FCU 2) Regulation/Indication Fault
TSM TASK 36-11-00-810-829-A
Loss of the Non-Return Function and Temperature Limitation Function of the Bleed Pressure-Regulator Valve of the Engine 1
TSM TASK 36-11-00-810-830-A
Loss of the Non-Return Function and Temperature Limitation Function of the Bleed Pressure-Regulator Valve of the Engine 2
AMM 36-11-41-200-001
Check of the IP Bleed Check Valve for Condition
AMM 72-00-00-200-001
Inspection/Check of Foreign Object Damage (FOD) (Bird Strike Included)
AMM 72-00-00-200-006
Inspection/Check of Foreign Object Damage (FOD) (Bird Strike Included)
AMM 72-31-00-290-001
Inspection of the High Pressure Compressor Rotor Assembly
AMM 72-31-00-290-002
Inspection of the High Pressure Compressor Rotor Assembly
AMM 72-52-00-290-001
Borescope Inspection of HPT Blades (from the front and the rear)
AMM 72-54-00-290-001
Inspection of the Stage 1-3 Blades
AMM 72-54-00-290-005
Inspection of the Stage 1-3 Blades
AMM 73-11-40-000-001
Removal of the Fuel Nozzles
AMM 73-11-40-000-002
Removal of the Fuel Nozzle for SAC Engines
AMM 73-11-40-400-001
Installation of the Fuel Nozzles
AMM 73-11-40-400-002
Installation of the Fuel Nozzle for SAC Engines
AMM 73-21-50-000-005
Removal of the CJ13 Harness
AMM 73-21-50-000-012
Removal of the J13 Harness
AMM 73-21-50-000-029
Removal of the CJ13 Harness
AMM 73-21-50-000-046
Removal of the HJ13 Harness for SAC Engines
AMM 73-21-50-210-001
Visual Inspection of the Wiring Harness
AMM 73-21-50-210-002
Visual Inspection of the Wiring Harnesses
AMM 73-21-50-400-005
Installation of the CJ13 Harness
AMM 73-21-50-400-012
Installation of the J13 Harness
AMM 73-21-50-400-029
Installation of the CJ13 Harness
AMM 73-21-50-400-046
Installation of the HJ13 Harness for SAC Engines
AMM 73-21-60-000-001
Removal of the Electronic Control Unit (ECU)
AMM 73-21-60-400-001
Installation of the Electronic Control Unit (ECU)
AMM 73-21-60-740-007
Correct Time Limited Faults (Non Asterisked) of the Engine Scheduled Maintenance Report
AMM 75-31-00-210-001
Visual Inspection of the Variable Bleed Valve (VBV) System
AMM 75-31-00-210-002
Visual Inspection of the Variable Bleed Valve (VBV) System
AMM 75-32-10-210-001
Visual Inspection of the Variable Stator Vane Actuator
AMM 75-32-10-210-002
Inspection of the Variable Stator Vane Actuator
AMM 77-21-10-200-001
Inspection/Check of the T495 Thermocouple Wiring Harness
AMM 77-21-10-200-002
Inspection/Check of the T495 Thermocouple Wiring Harness
3. Fault Confirmation
Subtask 77-00-00-710-135-A ** ON A/C NOT FOR ALL
A. Test
Not Applicable
4. Fault Isolation
Subtask 77-00-00-810-112-A ** ON A/C NOT FOR ALL
A. Do this procedure.
NOTE: There are many causes that can lead to an EGT sudden shift such as engine deterioration/failure, engine bleed management fault, EGT probes/harness failure, VBV system failure, hot air leak, Foreign Object Damage (FOD), Fuel nozzles contamination, etc...
NOTE: EGT difference between both engines is function of the engine performance level of each engine and therefore may be normal. Only a sudden shift should lead to initiate the following troubleshooting.
NOTE: Trend Monitoring should be reviewed first to determine whether the EGT higher on one engine can be explained based on the level of deterioration of the engine. Also, a shift on Trend Monitoring only noted on EGT and not affecting N2 and VSV should definitively concentrate the troubleshooting on the EGT indicating system.
   (1) If the EGT of one engine has a sudden EGT shift compare to the other engine:
  • Do a check of the Post Flight Report (PFR), of the Schedule Maintenance Report (SMR) or Class 3 Report AMM 73-21-60-740-007 and of the FADEC Last Leg Report for failure message including the following words:
    VBV, VSV, HPV, PRV, NAC TEMP, T495 SNSR
     (a) If failure message is present:
  • do the related troubleshooting procedure.
     (b) If nothing is found:
  • Do a visual inspection of the variable bleed valve system VBV system AMM 75-31-00-210-001.
    Check for VBV flexible shaft failure and for offset between the VBV actuator doors (doors set in different positions).
  • Do a visual inspection of the VSV system AMM 75-32-10-210-001.
  • Do an inspection/check for Foreign Object Damage AMM 72-00-00-200-001.
       1 If damage is found:
  • repair as necessary.
       2 If nothing is found:
         a if damage is found:
  • repair as necessary
         b If nothing is found:
         c if nothing is found, continue the troubleshooting as follows.
   (2) Do a check of the IP check valve AMM 36-11-41-200-001.
     (a) If damage is found:
  • repair as necessary.
     (b) If nothing is found (following troubleshooting is preferably to be done on a cold engine):
       1 Disconnect the CJ13 harness from the T495 main junction box (located in the leftcore compartment) and visually examine the T495 junction box receptacle and the CJ13 harness connector for damaged pins or contamination AMM 73-21-50-210-001.
         a If damage is found:
  • repair as neessary.
         b If nothing is found, continue the troubleshooting as follows:
   (3) Do an electrical resistance test through the main junction box between:
. pins A and B (1 to 10 ohms)
. pin A and the ground (> 20 megohms).
     (a) If the resistances are out of the specified limits:
  • Do an electrical resistance test of the T495 thermocouple wiring harness (probes lead assemblies and extension leads assemblies) AMM 77-21-10-200-001.
     (b) If the resistances are in the specified limits:
  • Reconnect the CJ13 harness on the Main Junction Box, disconnect the J13 harness from the ECU (4000KS) and visually examine the ECU receptacle and the harness connector for damaged pins or contamination AMM 73-21-50-210-001.
       1 If damage is found:
  • repair as necessary.
       2 If nothing is found:
  • do a resistance check of the cable between:
    . pins 12 and 13 (1 to 10 ohms)
    . pins 12 and 24 (> 20 megohms)
    . pin 12 and the ground (> 20 megohms).
         a if the resistances are in the specified limits:
  • no further maintenance action is required.
         b if the resistances are out of the specified limits:
   (4) If the fault continues during subsequent flights:
   (5) If the fault continues during subsequent flights:
   (6) Do a borescope inspection of the HPT Blades AMM 72-52-00-290-001.
   (7) Do a borescope inspection of the LPT Blades through the S17 port AMM 72-54-00-290-001.
   (8) Do a borescope inspection of the HPC Blades AMM 72-31-00-290-001.
     (a) If nothing is found:
   (9) If the fault continues during subsequent flights:
NOTE: Only if Service Bulletin 73-133 (cut dead end of fuel nozzle manifold) is not incorporated.
NOTE: Fuel nozzles position 3,5 and 7 are the most exposed to contamination in case of fuel manifold coking.
   (10) If the fault does not continue during subsequent flights:
NOTE: If the EGT exceedence is determined to be caused by fuel manifold coking, then replacement of all other fuel nozzles as well as replacement of the fuel manifolds is required.
Subtask 77-00-00-810-112-B ** ON A/C NOT FOR ALL
A. Do this procedure.
NOTE: There are many causes that can lead to an EGT sudden shift such as engine deterioration/failure, engine bleed management fault, EGT probes/harness failure, VBV system failure, hot air leak, Foreign Object Damage (FOD), Fuel nozzles contamination, etc...
NOTE: EGT difference between both engines is function of the engine performance level of each engine and therefore may be normal. Only a sudden shift should lead to initiate the following troubleshooting.
NOTE: Trend Monitoring should be reviewed first to determine whether the EGT higher on one engine can be explained based on the level of deterioration of the engine. Also, a shift on Trend Monitoring only noted on EGT and not affecting N2 and VSV should definitively concentrate the troubleshooting on the EGT indicating system.
   (1) If the EGT of one engine has a sudden EGT shift compare to the other engine:
  • Do a check of the Post Flight Report (PFR), of the Schedule Maintenance Report (SMR) or Class 3 Report AMM 73-21-60-740-007 and of the FADEC Last Leg Report for failure message including the following words:
    VBV, VSV, HPV, PRV, NAC TEMP, T495 SNSR
     (a) If failure message is present:
  • do the related troubleshooting procedure.
     (b) If nothing is found:
  • Do a visual inspection of the variable bleed valve system VBV system AMM 75-31-00-210-002.
    Check for VBV flexible shaft failure and for offset between the VBV actuator doors (doors set in different positions).
  • Do a visual inspection of the VSV system AMM 75-32-10-210-002.
  • Do an inspection/check for Foreign Object Damage AMM 72-00-00-200-006.
       1 If damage is found:
  • repair as necessary.
       2 If nothing is found:
         a if damage is found:
  • repair as necessary
         b If nothing is found:
         c if nothing is found, continue the troubleshooting as follows.
   (2) Do a check of the IP check valve AMM 36-11-41-200-001.
     (a) If damage is found:
  • repair as necessary.
     (b) If nothing is found (following troubleshooting is preferably to be done on a cold engine):
       1 Disconnect the CJ13 harness from the T495 main junction box (located in the leftcore compartment) and visually examine the T495 junction box receptacle and the CJ13 harness connector for damaged pins or contamination AMM 73-21-50-210-002.
         a If damage is found:
  • repair as neessary.
         b If nothing is found, continue the troubleshooting as follows:
   (3) Do an electrical resistance test through the main junction box between:
. pins A and B (1 to 10 ohms)
. pin A and the ground (> 20 megohms).
     (a) If the resistances are out of the specified limits:
  • Do an electrical resistance test of the T495 thermocouple wiring harness (probes lead assemblies and extension leads assemblies) AMM 77-21-10-200-002.
     (b) If the resistances are in the specified limits:
  • Reconnect the CJ13 harness on the Main Junction Box, disconnect the J13 harness from the ECU (4000KS) and visually examine the ECU receptacle and the harness connector for damaged pins or contamination AMM 73-21-50-210-002.
       1 If damage is found:
  • repair as necessary.
       2 If nothing is found:
  • do a resistance check of the cable between:
    . pins 12 and 13 (1 to 10 ohms)
    . pins 12 and 24 (> 20 megohms)
    . pin 12 and the ground (> 20 megohms).
         a if the resistances are in the specified limits:
  • no further maintenance action is required.
         b if the resistances are out of the specified limits:
   (4) If the fault continues during subsequent flights:
   (5) If the fault continues during subsequent flights:
   (6) Do a borescope inspection of the HPT Blades AMM 72-52-00-290-001.
   (7) Do a borescope inspection of the LPT Blades through the S17 port AMM 72-54-00-290-005.
   (8) Do a borescope inspection of the HPC Blades AMM 72-31-00-290-002.
     (a) If nothing is found:
   (9) If the fault continues during subsequent flights:
NOTE: Only if Service Bulletin 73-052 (cut dead end of fuel nozzle manifold) is not incorporated.
NOTE: Fuel nozzles position 3,5 and 7 are the most exposed to contamination in case of fuel manifold coking.
   (10) If the fault does not continue during subsequent flights:
NOTE: If the EGT exceedence is determined to be caused by fuel manifold coking, then replacement of all other fuel nozzles as well as replacement of the fuel manifolds is required.
Subtask 77-00-00-710-136-A ** ON A/C NOT FOR ALL
B. Test.
   (1) No test required.
   (2) If the fault continues:
  • Repeat the fault isolation procedure.
[Rev.8 from Aug 2018] 2026.04.04 04:37:32 UTC
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