Cummins x15 knocking noise

Knocking noise is produced by the injectors. However, deposits build up in the tips of fuel injectors, typically when there's fuel left in the injector tips after the engine is shut. Timing Chain Meshing. The timing chain connects the crankshaft and camshaft which will produce a meshing sound if it is too loose.

Have an overhead run, maybe out of time a bit.
Worse thing would be camshaft wear.

 

Timing chain?!? …., Gear driven!
The fault is common with x15 especially performance at about 1500-1600 rpm hard acceleration. Cummins says fuel pump timing, gears, normal sound… basically we really don’t want or can’t fix it. I had mine in 5 shops from Pete to Cummins. It’s still there and it is common. Had overhead, pump aligned, vibration analyzed, and fuel cutoff test done. Gonna run it till she breaks, then throw in a N14 or 3406.

 

First mistake was to buy a Peterbilt and second was for that engine. All kidding aside I think I would try what Judge said and do an overhead. Guessing you are around 500K on the truck as well and I think that is when they suggest it. Also you might try some snake oil like some people call it but I happen to be a believer in it Hot Shots Diesel Extreme for clearing it out.

 

Sounds exactly like a Cummins

 

Rawze.com: Rawze's ISX Technical Discussion and more - X15 noise and lack of power on a hard pull.

 

Yes, we know, instead of the timing chain or belt that is used in gasoline engines, the diesel engines use a steel time gear connected to the crank and cam.
Just used to saying timing chain vs Gear, but you get the point in that it’s doing the same thing.
(The Judge is not a diesel mechanic, per say, but did have 4 years auto mechanics)


Sticking EGR valves represent a good portion of the failures X15 owners see, much of which can be traced back to extended idle time. A larger issue revolves around high-pressure fuel pump (or injection pump) failure, with a major recall being ordered for them in 2021.
See if it’s been one of the recalled/fixed ones.
Being a 20. it’s probably an 19 engine anyway but without looking back i can’t remember which engines were recalled.

 

They still haven't figured out the fuel pump yet? That #### things been destroying the isx since the 2250 generation. Cummins is a joke.

 

The answer to your question…. no! Hehe
At low idle at a stop I can hear my fuel pump wine. Cummins says it’s normal…. I hear “normal” allot from them.

 

high pressure fuel pump is junk