N14 Top End Knock

Google Play
Manualslib - User Guides & Owners Manuals library
4.7
(3K)
Try this link search:
Cummins n14
That should get the shop manual.
Good luck.

 

Diesel Controls does good work, but the shop I am buying big cam parts from now also does N14 injectors and that is where I have been sending people.

Premco out of Lampasas, TX.

 

I have the shop manual, but its assuming a dry engine, and a fresh head lol. Dont have either of those but it does say to lube it up with oil so part 3 of the question solved. Kind of forgot I had a printed copy and a pdf on my phone.

 

There is a specific brush that is used to clean the injector cups. It MUST be used before the install. As far as fuel on the top of the piston is concerned, a plastic tube adapted to a vacuum is the best way to get down to the top of the piston.

 

I'll give that a try, any ideas on where I could get one of those brushes, dealer couldn't find it in their catalog when I went today and Cummins HQ says they only sell to dealers and certified shops.
Edit: found them online, it looks like theirs three, a spiral brush, and then two normal brushes. I'm assuming the spiral brush is the one to use, according to their site its stainless steel filaments.

 

Call these guys.
Specialty automotive diesel tools & diagnostic tools including NEXIQ USB-Link: Apex Tools

There are different size brushes for different bore sizes.

 

Thanks for the link, this one says copper bristles and I've got one ordered. I'm going to give a stiff bristle nylon brush a try and see if that will clean it out at all while I wait.
The tech at the dealer is convinced the injector is stuck open and recommended I inspect the piston crown, the driver drove it about 1000 miles in its condition so I'm hoping the piston isn't torched. Any odds on the likelihood its torched?

 

If he was seeing a lot of black smoke it's highly likely that it got too hot.

Nylon bristles are worthless.

 

Where's @spyder7723? Thought he was the n14 guru?

@Bakerman knows his way around one too.

 

Not a hint of smoke according to the driver, I tailed him empty for a few city miles and there wasn't any smoke then either. Couldn't find my thermometer but feeling the exhaust manifold, number 1 and 2 holes were about the same temp at idle, he said if it was stuck open it would be too hot to touch seconds from start up. Unplugging the injector gets rid of the knock but RPM stays about the same, doesn't drop just gets rid of the knocking noise.
I'm with you on the nylon, but figured it would be worth the try, driver wants to get back on the road ASAP and it's either a nylon brush or some brass wool for cleaning it out because he doesn't want to stick around for the end of the weekend.