Perkins Various (model dependent on APD-UL variant) Engine Engine

• Vibration
  Cause: Fault in atomizers or atomizers of an incorrect type, Restricted movement of engine speed control, Engine temperature is too high, Fan damaged, Fault in engine mounting or flywheel housing, The engine temperature is too high: Restriction air filter/cleaner or induction system, Fault in atomizers or atomizers of an incorrect type, Fault in cold start system, Restriction in exhaust pipe, Fan damaged, Too much lubrication oil in pump, Restriction in air or water passage of radiator, Insufficient coolant system
• The starter motor turns the engine too slowly
  Cause: Battery capacity to low, Bad electrical connection, Faulty in starter motor, Wrong grade of lubricating oil
• The pressure of the lubrication oil is too low
  Cause: Wrong grade of lubrication, Not enough lubrication oil in sump, Defective gauge, Dirty lubrication oil filter element
• The engine runs erratically
  Cause: Fault in fuel control, Restriction in a fuel system, Fault in fuel lift pump, Dirty fuel filter element, Restriction air filter/cleaner or induction system, Air in fuel system, Fault in atomizers or atomizers of an incorrect type, Fault in cold start system, Restriction in fuel tank vent, Restricted movement of engine speed control, Engine temperature is too high, Incorrect valve tip clearances
• The engine knocks
  Cause: Faulty in fuel lift pump, Fault in atomizers or atomizers of an incorrect type, Wrong type or grade of fuel used, Fault in cold start system, Engine temperature is too high, Incorrect valve tip clearances
• The engine does not start or difficult to start
  Cause: Starter motor turns engine too slowly, Fuel tank empty, Faulty in fuel control solenoid, Restriction in a fuel pipe, Faulty in fuel lift pump, Dirty fuel filter element, Air in fuel system, Faulty in atomizers, Colt start systems used incorrectly, Fault in cold start system, Restriction in fuel tank vent, Wrong type or grade of fuel used, Restriction in exhaust pipe
• Not enough power
  Cause: Restriction in a fuel pipe, Faulty in fuel lift pump, Dirty fuel filter element, Air in fuel system, Restriction air filter/cleaner or induction system, Restriction in exhaust pipe, Fault in atomizers or atomizers of an incorrect type, Restriction in fuel tank vent, Wrong type or grade of fuel used, Restricted movement of engine speed control, Engine temperature is too high or low
• Misfire
  Cause: Restriction in a fuel pipe, Faulty in fuel lift pump, Dirty fuel filter element, Air in fuel system, Fault in atomizers or atomizers of an incorrect type, Fault in cold start system, Engine temperature is too high, Incorrect valve tip clearances
• High fuel consumption
  Cause: Restriction air filter/cleaner or induction system, Fault in atomizers or atomizers of an incorrect type, Fault in cold start system, Wrong type or grade of fuel used, Restricted movement of engine speed control, Restriction in exhaust pipe, Engine temperature is too low, Incorrect valve tip clearances
• Crankcase pressure
  Cause: Restriction in breather pipe, Vacuum pipe l
• Blue or white exhaust smoke
  Cause: Wrong grade of lubrication, Fault in cold start system, Engine temperature is too low, Incorrect valve tip clearances
• Black exhaust smoke
  Cause: Restriction air filter/cleaner or induction system, Fault in atomizers or atomizers of an incorrect type, Fault in cold start system, Wrong type or grade of fuel used, Restriction in exhaust pipe, Engine temperature is too low, Incorrect valve tip clearances, Engine over load

Compiled from service & troubleshooting documentation across every generator set that uses the Perkins Various (model dependent on APD-UL variant).

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.