ENGINES


• Contaminated or defective fuel control unit – Disconnect fuel control unit outlet and check for flow while motoring; if no flow, remove fuel control unit for bypass valve check.


• Dirt in pneumatic section of fuel control unit caused incorrect signal effect – Clean or replace unit


• Contaminated P3 filter-restricts P3 signal, causes slow acceleration – Change P3 filter


Temperature Limited • Instruments are out of calibration – Have all instruments calibrated


• Selected wrong torque from graph – Recheck


• Dirty compressor – Perform a compressor wash


• Excessive accessory load – Place the generator off line; check accessories for extra loading


• Compressor FOD – Check compressor first stage blades


• Air leaks – Check all gas generator case gaskets and flanges for leaks


Low Oil Pressure • Low oil level


– Check the tank oil level; check oil consumption


• Defective oil pressure indication – Check with direct reading gauge


• Pressure relief valve malfunctioning, probably stuck open – Replace unit


• Internal oil leak – Will cause oil smoke on start or shutdown and oil smell in cabin area


• Failed heat shield in power section – Causes excessive heating of oil; oil cooler might not be able to handle the added temperature.


High Oil Pressure • Defective oil pressure indication – Check with direct pressure gauge


• Pressure relief valve malfunctioning – Stuck closed; oil pressure will follow N1 rpm


High Oil Temperature • Insufficient supply – Check tank level; replenish supply, check consumption


• Defective cooling system – Check oil cooler thermostat


• Failed heat shield in power section – Causes excessive heating of oil; remove and repair power section


There you have it, some of the more common problems and solutions in


working with gas turbine engines. My thanks to those of you who contributed to this article. If you have some issues and solutions not discussed here that you would like to share with our readers, please send them to my attention. You can even remain anonymous if desired.


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