Generator produces a loud knocking or metallic tapping noise from the engine area during operation.

Safety first: If the noise is sudden and severe, shut down the generator immediately to prevent catastrophic engine damage.

• Localize the noise: Use a mechanic's stethoscope or a long screwdriver to listen at different engine components (valve cover, block, injection pump) to identify the source.
• Check oil level and pressure: Verify engine oil level is correct. If the controller shows low oil pressure or the oil appears contaminated with metal, do not continue running.
• Injector test: One at a time, slightly loosen injector line nuts (with engine running) to see if the knock changes. A change indicates injector-related knock; have injectors serviced.
• Valve clearance: Inspect and adjust valve lash to Kubota specifications if ticking noise is from the top end.
• Internal damage: Deep knocking from the crankcase often indicates bearing damage and requires full engine teardown by a qualified technician.