shield. Loose or broken torsional damper or drive pulleys. Excessive piston-to- ... visual inspection. Remove accessory belts; perform visual inspection. Check with ... or rod bearing clearance. Remove drive belts; perform visual inspection, service or ... . Check engine codes and ignition timing settings; reset to specifications; ... Start-up knock, lasts a few seconds. Timing chain tensioner not properly set. ... Improper oil viscosity. Bearing knock. Hydraulic lifter bleed down. Check filter with ... . Knock at idle, engine hot. Drive belts too tight; accessory belt pulley ... pin (double knock). Loose torsional damper. Remove accessory belts; observe change ...