Operation CHARM: Car repair manuals for everyone.

Engine Noise Diagnosis






Engine Knock Noise (Fuel Knock)






Intermittent Noise on Idle Only. Disappearing When Engine Speed Is Increased






Noise at Slow Idle or With Hot Oil; Quiet at Higher Engine Speeds or With Cold Oil






Noise at High Vehicle Speeds, Quiet at Low Vehicle Speeds






Noise Regardless of Engine Speed






Valve Train Noise






Vibrating or Rattling from Exhaust System






Exhaust Leakage and/or Noise