Knocks at Idle When Hot

- Loose or worn drive belts. Adjust tension or replace as necessary.

- A/C Compressor or generator bearing. Replace as necessary.

- Valve train. Replace parts as necessary.

- Improper oil viscosity. Install proper viscosity oil for expected temperature.

- Excessive piston pin clearance. Ream and install oversize pins. Or replace piston and pin.

- Connecting rod alignment. Check and replace rods as necessary.

- Insufficient piston to bore clearance. Hone bore and fit new piston.

- Loose crankshaft balancer. Torque and/or replace worn parts.

- Piston pin offset to wrong side. Install correct piston.