How do you identify the knoCking sound of a motor vehicle?

Answer 1

A experienced ear can usually identify the type of problem just by the sound.

To Narrow down the location try:

• Shorting Each cylinder so it does not fire, if the knock goes away or substantially reduces for one you have narrowed you search to one cylinder.
• Use a mechanics stethoscope, this will localise the noise and lead you to valves, bottom end, piston or timing system
• If this is a Common Rail injected unit a computer scanner to shut off injectors will help.