I've posted about this numerous times, and still fishing for anyone else with a similar problem and/or solution. It's NOT related to the TSB for the little tag on the radiator support. The noise seems to be coming from the oil filter/alternator area, and it happens ONLY when the truck is at full operating temp and the RPM's are near 1200. It goes away any lower, or any higher. Very loud and VERY annoying...

 

What have you ruleled out? Alternator, any other accessory drive items?

 

At this point, nothing has been ruled out. With a mechanic's stethescope (sp?), the noise is strongest from the top of the oil filter housing, where it attaches to the block. This housing contains the oil filter bypass valve, which is little more than a spring and check mechanism. The dealer tech has already replaced the spring once with a revised part number (a little softer 'k' value), but the noise persists... Anyhow, just wondering if anyone else has dealt with this, or if I'm still the only sucker in the world who's Cummins makes this racket? Think of baseball cards in bicycle spokes at about 80mph...

 

I too noticed a buzzing coming from the engine bay on my "03. Noticed it after I got it back from the dealer, who replaced defective air conditioning lines. I drove about a block and noticed a buzz, at low RPM. Popped the hood and noticed the auto transmission dipstick tube vibrating so much it was a blur. The factory tie wrap anchoring the tube to an adjacent line wasnt doing the job. I wrapped a piece of heater hose around the dipstick tube to reduce metal to metal rubbing and noise and added one more tie wrap. The noise seems to have disappeared. You may want to look at this area on your truck.

 

Interesting - - I have been griping about a "rattle" (I call it that) and I have the six speed also. I have never heard of anyone with the slusher complaining. Mine happens when cruising at about 1200 (the loudest) in lower gears with no load. Typical time would be returning slowly to my campsite in the park in third gear at about 11 - 1400 rpms. No one seems to know what it is - - the dealer tells me he thinks it is diesel rattle. OOHHHH, then why doesn't the slusher do it too?

 

The guys got a stick not an auto Mr. Airplane driver.

 

Fiver - We may be on the same issue here... I hear mine whenever I'm tooling through my neighbor hood on the way home, either rowing up or down through the gears, with all the noise bouncing off the fences. Actually I hear it anytime there is stuff around to shoot the noises back toward the truck, like the woods, parking lots, alley ways, etc. Can't say it's only when unloaded though, mine doesn't care if I've got my trailer back there or not...

 

Well, you are correct on the loading - - I was referring to loading by not pushing it, rather just barely holding speed. My service tech noticed it just jumping in and moving it forward in the service line - - asked me "what is that?" I asked him the same question back - - what do you think I have been telling you for one year. Really a nasty sound for so nice a truck - - more like a Ferd.

 

check your transmission dipstick mine was vibrating at idle in gear and really noisey in cab . i took a real small bungy cord and looped it to firewall fixed mine

 

He has a stick not an auto