I have a strange noise from my engine. This noise varies with engine speed and throttle position. It happens from approx 1,200 - 2,500. I tried capturing the noise on video but unfortunately the video camera would not would not pick up the noise at lower RPMS. So, for this clip I just kept hovering in the ‘noisy zone’ (this is not my usual driving style!)

http://www.youtube.com/watch?v=PWQ70qrCzBE

When watching the video you will hear the noise I am mentioning at the following times:
12 seconds, 15, 18, 21, 24, 28, 32, 38 & 43. Shortly after 43 seconds I put my foot down and it sounds really smooth. This smoothness at WOT is true for any point in the rev range. I am thinking it is an injector or fuel problem as it goes away when the throttle is wide open.

There is also a slight misfire when it is held at a steady RPM.

The dealer gave me some Stanadyne magic potion and I ran that through (2) full tanks of fuel with no change to the condition. They also suggested that I work the engine hard so I hooked up our 6,000lb travel trailer and kicked the **** out of it for 220 miles to the coast and did the same back – the engine still rattled and still had the misfire.
So, the dealer was at a loss and their last resort was to pull the injectors and clean them. Apparently there was a fair amount of carbon on them and guess what – it still rattles and has a misfire.

I took it to a diesel specialist and they ran an injector contribution check on it – this showed #6 was running at 93%. I don’t remember the exact numbers but it was something like:- 97, 106, 98, 107, 100, 93. Could it be #6 throwing things off and creating the misfire feeling?

I also read on this forum that the vibration/misfire can be caused by the dual mass flywheel.

I am taking it to a different dealer next week to see what they can find.

The truck starts just fine, it pulls like a steam train and has excellent fuel economy.

What on earth is causing the noise and the misfire?

Thanks in advance for your help.

 

sounds normal

 

I can hear the noise your talking about at the times you listed, can't tell if it's injectors or not. The first dealer you took it to that said there was carbon build up on the injectos... WELL DUH!!! IT'S A DIESEL! it will. Not yelling at you just the dumb a$$ dealer. the injector test you had done does make it sound like you might have a weak one. do you have any mods done, smarty, or any other programers that might do weird things?

 

Sounds like pressure rattle...were you running just past tip-in on the throttle???

If so then I get that and my RP gauge tells me that psi is in the 20K area and it varies as the rattle goes up or down in sound.

As psi varies around 17.5K-20K under very light throttle I get the same noise..very normal. (To me at least)

 

Injectors are covered under Cummins warranty. Check fuel filter housing for any contamination before you bring to dealer. Such as rust or water in fuel filter housing. If contamination is discovered by a dealer could void your warranty. What is your set point pressure and running pressure? pressure should not vary more then 500 psi from high to low. If it does you could have FCA going out, engine would have hammering sound and rpm fluctuation when idling. Check valve clearances are they in spec? Read TSB will give you all tests and specs to help diag your truck. Good Luck[URL="http://Luckhttps://www.dieseltruckresource.com/forums/showthread.php?t=218069"]

 

My dads 03 sounded the same and it ended up being injectors.

 

Forgot to add my signature in the first post.

 

Sounds like mine. Been making rattles and other strange noises since day one. I have 78K miles on her and have decided she is just a noisy biotch. BTW I had all 6 injectors replaced by the dealer at around 35K and the rattle was and is still there. Evidently Dodge considers injector variance of up to +/- 11% to be normal ans acceptable.

 

read fast, but no codes mentioned? nothing like a 148 perhaps ?

 

YES!!!!!!!!!!!!! This is the same injector clatter I have been hearing as well!!!! Mine was MUCH better with no fuel additives... I have been told over and over normal. Everything on my UOA is perfect, fuel economy is perfect...

 

Wouldnt sweat it!! Unless it gets WAY WORSE, or something doesnt feel/sound right...keep on loving that cummins!!!

 

Mine does it at about 2000RPM, light throttle only.
Ted

 

I spend most of my time at light throttle as this thing has so much power. I don't want to look stupid working each gear really hard - especially when I will be stopping at lights every 1/2 mile!

I have figured out that I can make the noise go away by turning up the radio However, the misfire/stutter can still be felt through my butt, through the floor and in the steering wheel.

What would cause the misfire?