LLY: duramax knocking..

[JMK777]

Can an fpr make it knock? Ik u told me on df u doubt it is a rod. And i would think if it was a rod it woulda fully bent or broke by now.

fpr can make it knock as well as lop.
I would log rail next if i where you. how dose it sound while cruising, say 45mph ?

 

[kman2468]

i can hear a slight knock while cruising it is mostly with throttle, it can be light, or heavy

 

[kman2468]

i logged actually vs rail pressure

 

[05stocklly]

I think I had the same problem. But mine felt like it had no balls when trying to accelerate too. I turned the programmer to stock put some ATF in the feul to help clean the fuel system out, run it hard for acouple of weeks and noticed it was gone. I bump the programmer back up and all was good. Still not sure what it was but its gone for now.

 

[kman2468]

well ive put additives in it and it seemed like it helped, and then when that stuff was gone, it was back. or atleast what i could tell..idk

 

[05stocklly]

The only why I can explaine the knock I had was it accually sounded like a diesel when I stepped on even just a little, not the nice Duramax sound.

I was told that it was probably some build up from the higher tune, and not really using the power, like towing something works the motor harder than just quick take offs and then cruising. Just don't go crazy with the ATF I was told just a couple ounces a fill up will do.

 

[kman2468]

well thats what im saying it isnt the normal duramax noise. could be normal diesel? but egr wouldnt cause this would it? cause i dont have mine blocked

 

[05stocklly]

I don't have my egr blocked either. I'm not saying it will work but it might be worth a shot. Maybe someone else will chime in about this.

 

[kman2468]

well..its getting worse..and it sounds like something is about to give
i dont have money for what i think it is. cause of course im thinking of the worst that it could be a bent rod..

 

[Akdiesel]

Why don't you follow the advice that was given and do a compression test?:thumb:

 

[kman2468]

because i dont trust myself enough to do all that yet..

 

[Akdiesel]

Understandable but if it was a bent rod wouldn't you like to know...i mean closing your eyes and pretending it isn't there won't make it go away

 

[duratothemax]

you need to do a compression test. No one can help you or give you any more advice until you do. I highly doubt its a bent rod.

 

[ripmf666]

If it's a bent rod won't be long til he can see it up close. I would atleast try and save your block and crank and what ever other part you could. It's better then looking for a whole new motor to build or replace with.

 

[Redbowties88]

x2 kyle get a compression test and for giggles run your balance rates again and use the dvt tool to turn off injectors..

 

[kman2468]

is it possible to like drive a little with one cylinder turned off? because that is only way i can tell its knocking is in the higher RPM's like near 1500. and only in drive. or is it bad? and my balance rates were all in check. but my number two was 3.6. anyone know how much dealership charges for compression test? i work two jobs and dont have time to do it

 

[Redbowties88]

you can drive with an injector turned off. i drove like 10 miles with only 4 working

 

[kman2468]

i can? well ok thats good um so if it stops knocking then that will let me know if its injector right? or if its turned off could it still be rod?

 

[SparkZ03DMAX]

Dam now ur making me worry about a bent rod.

 

[Akdiesel]

Running the power levels you guys are at I HIGHLY doubt you bent a rod. I'm running a pony or two more and have yet to have any worries...