By removing the injector wiring one at a time I found the number 5 injector to be bad, by disconnecting the number 5 wiring the knocking stopped,apparently it was pumping excess fuel into that cylinder and pounding it, that is what was making the knocking noise and the excessive carbon particles coming out of the exhaust. As I had no signs of the black death around the injector I didn't even need to clean the injector bore, the 5th cylinder is to far back to work on anyway. All I did was replace the one injector with a rebuilt one and a new injector bolt and seal and the engine has run fine for 6 months now. I was able to loosen the injector by loosing the injector bolt a bit and then starting the engine.

super helpful, I am about to go do that test, sound is exactly the same

Please watch out for that string when you bent over the engine. Cheers

I have a knocking in my van 06 Freightliner 2500 did you ever fix yours ? What caused the problem if so ? Thank you for your video and insight

I literally had the same exact sound same loudness in my sprinter I was wondering if it really indeed was an injector I keep on plugging everyone that doesn’t stop, but the sound is exactly the same

I guess loose injector knocking at the vanity cover.

any update on what the knock was? exact sound I have on mine.

The fix to the problem is in the first comment

Mine has the same sound but not so loud. What is it????

More like a piston slap

Hi Michael that was a bad injector? Making that sound? Mine is doing something similar but definitely not as loud