rattle noise coming from motor

[Mobius1]

My motor has recently developed a noise which is best described as a rattling noise. I did a search on the forums for a possible solution, I found a possible cause could be a bad injector. However the truck runs just fine, no stumble, miss or hesitation, no blue, black or excessive smoke at all, so I really don't think it is that.



I get the noise when either the engine is cold or warm. It happens when I put a load on the motor (If I am at a stop and I use about 1/2 throttle, I will get it briefly then it is fine) I can also get it to happen say if I am going up a hill and I accelerate to make the transmission downshift, it will do it there too.



I use diesel kleen at every tank full. Does any body have any ideas as to what it could be?

 

[nickleinonen]

what engine rpm when it does it?

 

[Mobius1]

It happens about mid to high range 1400 to about 2500 rpm. BTW I forgot to say that this happens with the tst on 0 or 3x3. I also had a rotteck crank sensor but I removed that and the noise is still there

 

[RMalone]

I have the same noise, mine showed up after an injector change (bodies and tips). The injectors were changed because the truck wouldn't maintain rail pressure. Now the truck maintains rail pressure but I get that funny rattle exactly as described (the truck holds rail pressure now and goes like a raped ape). I too hear it with the tst turned on or off or completely removed from the truck, and I hear it with the VA pressure box turned on, mid or full. Sorry I can't answer why but I will definately keep an eye on this thread.

 

[RustyJC]

2nd generation trucks with the EZ were prone to do this - especially HOs like mine. It's generally been attributed to more injection timing advance than the HO engine really likes and was nicknamed "timing rattle". You can hear it start rattling for a few seconds, then disappear - like the EZ is diddling with the injection timing. This is especially apparent under lighter or constant loads and seems more prevalent when the engine is not up to temperature or the outside temperatures are cooler.



Could that be the case on your 3rd generation as well?



Rusty

 

[Mobius1]

2nd generation trucks with the EZ were prone to do this - especially HOs like mine. It's generally been attributed to more injection timing advance than the HO engine really likes and was nicknamed "timing rattle". You can hear it start rattling for a few seconds, then disappear - like the EZ is diddling with the injection timing. This is especially apparent under lighter or constant loads and seems more prevalent when the engine is not up to temperature or the outside temperatures are cooler.



Could that be the case on your 3rd generation as well?



Rusty

Thats sounds like that might be it. I thought the EZ for the 05 just did fuel pressure and not timing?

 

[MCummings]

Our '05 when it was stock would do the same thing. Sounds like too much timing on a gasser, but it comes and goes at anytime...





Merrick

 

[RustyJC]

Thats sounds like that might be it. I thought the EZ for the 05 just did fuel pressure and not timing?

Dunno about the 3rd generation EZ. The 2nd generation EZ modified injection timing and fueling rates.



Rusty

 

[RMalone]

Rusty your description of the symptoms is spot on. I have noticed it with or without the TST and/or the VA boxes (VA=no timeing). It definately sounds like a timeing issue and it does come and go. On mine it is more pronounced at low temp (engine and ambient). I get NO other symptoms the truck has never run so well. I am going to set the valve lasche[sp?], and see if that helps.



Has anyone had any problems that could be attributed to this rattle?? I ask because right now my truck is running very good, except for that disconcerting rattle.

 

[Highfinance97]

Our '05 when it was stock would do the same thing. Sounds like too much timing on a gasser, but it comes and goes at anytime...





Merrick

My buddy has the same problem.





Michael

 

[Mobius1]

Rusty your description of the symptoms is spot on. I have noticed it with or without the TST and/or the VA boxes (VA=no timeing). It definately sounds like a timeing issue and it does come and go. On mine it is more pronounced at low temp (engine and ambient). I get NO other symptoms the truck has never run so well. I am going to set the valve lasche[sp?], and see if that helps.



Has anyone had any problems that could be attributed to this rattle?? I ask because right now my truck is running very good, except for that disconcerting rattle.

Same thing with mine tst is off ez is on lvl 1. Comes and goes, but its more pronounced when the engine is cold. Truck runs fine just get me worried when I hear that noise

 

[MCummings]

My buddy has the same problem...

I wouldn't consider it a "problem".



If you read some of the EFI Live threads here, it seems like it might be the computer advancing timing for when the third injection event will be shot.



Merrick

 

[CTDFreak]

I have the same thing, and I didn't notice until a month or so ago. This may be a total stretch, but could it be the change to ULSD?



I've searched and found threads ranging from injectors to valve lash. I've tried the suggestion of "just add some Diesel Kleen and run it like a raped ape for 10 miles, it will clear right up!" Didn't work for me...

 

[MMeier]

I too had a strange "rattle", could best be described as sounding like one of those 6. 0 POS thingies, woulod come and go at will, changed out my FCA and have not heard since. Also, would do a strange idle "dance" occasionally too. That has not occurred since then either.

 

[CTDFreak]

FCA? Am I having a brain fart? What is that?

 

[MMeier]

FCA? Am I having a brain fart? What is that?

FCA= fuel control actuator, back side of CP3 , held in with 3 small screws, and one electricaql connection. Buy it at Cummins, ~$100, buy it at the stealership~400 or so.

 

[CTDFreak]

thanks. how did you know that this is what needed to be replaced? How would I know if that is what I need (short of just replacing it)?

 

[MMeier]

Actually didn't, just posted my symptoms up here and the general consensus was that was bad. Took a chance, but as is usually the case , our guys here were right! And if that wasn't it, you now have a spare for when it does go bad!

 

[CTDFreak]

my symptoms are actually a bit different than yours. More similar to the original poster, but may have to give it a shot if I can't find another solution. Mine is much more of a timing type rattle under load (like on an old gasser).

 

[Mobius1]

Here is some news on the subject. The past 2 tank fulls have been ulsd 15 ppm. What I have been normally been using is ulsd 500ppm, and the noise seemed to have pretty much go away. On my last full tank full I bought a bottle of the valvoline/cummins fuel conditioner. It says that 1 bottle can treat 250 gallons. I also have been using diesel kleen too. Should I just go with one or the other? Because now (maybe its a coinsidence) but the noise seems like it went away!