Diagnosis should include
- listening for engine noises
- conducting a visual inspection for loose or damaged components
- determining whether the noise is external or internal to the engine
- operating the engine at various revolutions per minute (RPM) to help isolate the noises and vibrations
- determining the necessary action.
ASE 3: Diesel Engines: A. General (P-1)
Process/Skill Questions:
- Why might the noise change at different RPM?
- What tools should be used to measure noise level?