Generator produces excessive mechanical noise or knocking during operation; no error code.

Safety first: Keep clear of moving parts while the generator is running. Use hearing protection.

• Check oil level: Immediately verify engine oil level and top up if low. Running with low oil can cause severe damage.
• Inspect mounts: With the engine off, check that all engine mounting bolts are tight and that rubber mounts are not torn or collapsed.
• Listen for source: Use a mechanic's stethoscope or a long screwdriver to localize the noise (valve cover, crankcase, alternator). Knocking from deep in the engine may indicate bearing damage and requires professional service.
• Stop if severe: If noise is loud or worsening, shut down the generator and arrange for inspection by a Hyundai Power technician to prevent catastrophic failure.