My 7.3 makes a knocking noise when its running. I was told that I shuld drain the fuel filter and fill it wit atf fluid and let the truck run. They said it will lube the IP and injectors and shuld fix my knocking problem. Is it safe to do this and will it fix the knock.

 

if it is an injector knock it might. either fill it with atf or dieselkleen. i fill mine with atf every time i change the filter.

 

IMO, let the proven and specifically designed fuel treatment products go in your fuel system, and leave the aTf in the TRANSMISSION.

 

everybody knows atf is a solovent. works great as one. never had an issue. i will put almost anything into the tank on my 6.9( atf, WMO, hydro) and NEVER had a problem.
i will normally fill the filter with dieselklean or the like, but every now and then throw a filter full of atf at it. quiets everything down.

 

i run stanadyne additive, an ounce everytime i fuel up stuff works amazing

 

Ok I ran a filter full of atf fluid but it didn't solve the knocking sound what else could it be?

 

with it running, crack 1 injector line loose at a time till the knock goes away. that will narrow down what cyl is doing it. then try replacing that injector.

 

ill give that a shot.

 

What could be happening is one of your injectors isn't closing completely and leaking fuel into the cylinder. The knock you hear is a result of the precombustion. I am having this problem with my truck right now as well. Unfortunately for me my DMF is so worn that disabling 1 injector causes it to make so much noise that I cant tell if the knock has gone away.

 

i havnt tried cheacking the injectors yet but im thinking im just going to order all new bb code injectors because im not sure how old these ones are they look original.