Compression knocks
| Cause | Correction | |
| Air in the fuel system |
 |
Bleed the fuel system. |
 |
||
| Poor quality fuel |
|
Verify by operating from a temporary tank with good fuel; Clean and flush the fuel supply tanks. |
|
||
| Engine overloaded |
|
Verify that engine load rating is not being exceeded. |
|
||
| Incorrect injection pump timing |
|
Check/time injection pump. |
|
||
| Malfunctioning injectors |
|
Replace injectors. |