Knocking sound when i accelerate

[bigbear1]

Good evening Everyone,

I have a 2015-16 Merc A Class and today as i was driving when i put my foot on the accelerator a loud knocking appeared from nowhere.

It sounded like a machine gun, took it to a guy who lives locally and he said it sounds like one of the fuel injectors are not working and its mis-firing, allthough a quick search on google brings up a whole host of potential problems.

Does anyone have any idea or experienced this before?

 

[Trickythemerc]

An overfueling injector would cause a knock and black smoke from the exhaust. Big end failure would also give you a knock, does it do it all the time or just under load ?

 

[bigbear1]

Its when i start the car the knocking starts, sounds like its coming from under the bonnet. when i accelerate it sounds like a machine gun going off.

Horrible sound.