Ping and knock are usually related to one of the following:
- Lack of proper EGR flow or air in EGR flow.
- Carbon buildup causing higher compression ratio or hot spots.
- Wrong type of plugs or wrong heat range.
- Wrong static timing (improperly installed timing belt).
- Wrong ignition timing (octane jumper, Chip).
Ping or rattle from these usually increases at moderate load.
Plug wire crossfire can produce a more limited knock under wide load conditions.
A constant heavy knock under load may be a bad rod bearing.
