Exhaust valve knocking
MAN B&W L23/30H technical information, four-stroke auxiliary diesel engine (generating set)
Possible cause
Loose adjusting screw, damaged push-rod disc
What to do
Manufacturer's manual, p. 38Inspect and replace parts
Other MAN B&W L23/30H technical information faults
Exhaust temperature rises on all cylindersCharge air cooler ineffective, fouled air/gas passages, poor fuel, wrong camshaft positionExhaust temperature rises on one cylinderDefective fuel valve, leaking exhaust valve, blow-by, damaged fuel camExhaust temperature drops on one cylinderAir in fuel pump, sticking fuel valve spindle, sticking pump plungerEngine rpm dropsLow fuel pressure, water in fuel, governor or valve faults, increased frictionSmoky exhaust in normal runningFouled turbocharger, defective nozzles, low air supplyLube oil pressure failsPump defective, filters or cooler fouledEngine does not turn on startLow air pressure, main valve closed, pinion not engaging, start valve stuck, electrical fault
From the manufacturer's manual “MAN L23-30H technical information”. Check against the original on board before work.