TM  55-2840-241-23 Table   4-1.   Troubleshooting   (Continued) Item Trouble Probable   cause Remedy 41.1    Exhaust    duct a.   Combustion   liner emitting    sparks. damage. b.   Damage   to   turbine   or compressor   blade,   vane, or  seal. 41.2    Excessive vibration. 42   Deleted . 43   Deleted . 44   Deleted . 45   After   fire. a.   Loose   engine   mounts. b.   Turbine   wheel   blade failure. c.   Foreign   object   damage, eroded  vanes,  blades,  or plastic    coating. d.  Bearing  or  lube  oil pump   failure. e.    Accessories    failure, such   as   starter   generator or  fuel  pump. f.   Cause   uncertain. a.   Oil   leak. b.   Burner   drain   valve line   obstruction. c.   Sticking   burner   drain valve. d.  Fuel  nozzle  valve stuck   open. e.   Gas   producer   fuel control  cut-off  valve  not fully  closed. 46   High   temperature Fuel  control  shutoff  valve during   shutdown. not  closed. (Also  refer  to  item 56.) a.   Inspect,   repair,   replace combustion  liner.  (Refer  to  para 7-20.) b.  Replace  engine.  (Refer  to  TM 55-1520-228-23.) a.   Inspect,   tighten   mounts. b.  Replace  engine.  (Refer  to  TM 55-1520-228-23.) c.  Replace  engine.  (Refer  to  TM 55-1520-228-23.) d.   Check   magnetic   inspection   plugs for   particles.   If   particles   have accumulated,   send   engine   for overhaul. e.   Replace   accessory. f.  Replace  engine  if  excessive vibration   persists.   (Refer   to   TM 55-1520-228-23.) a.  See  item  47. b.   Check   the   drain   lines.   Clean   or replace   as   necessary, c.  Replace  valve.  (Refer  to  para 5-38. ) d.  Replace  fuel  nozzle.  (Refer  to para   5-15.) e.   Check   linkage   or   replace   fuel control.  (Refer  to  para  5-12.) Check  linkage  to  fuel  control.  Verify that  twist  grip  was  in  the  closed position. 4-12 Change 14