4d56 deisel engine, after opening the engine, good idle but when i accelerate knoking sound appear
Not sure what you mean by opening the engine.
The combustion process of a diesel is not the smooth burn and increase in pressure of a petrol engine but is virtually an explosion causing a sudden rise in cylinder pressure. This is the source of the typical diesel knock and is more pronounced in some engines and some injection systems, especially when accelerating. It can be scary for those unfamiliar.
Electronic control tends to soften the noise.
Knocking might be the result of a mechanical problem (piston, connecting rod bearings, etc.) but if these things have been eliminated other causes of excess knocking can be excessive injection timing advance, dribbling injectors, bad spray patterns...
Jun 19, 2016 |
Cars & Trucks