What's going on? Odd sounding idle at times

[12ga diesel]

I'm still learning things with my Cummins, even 9 months after buying it, and now with almost a full winter under my belt with this truck, I hear an odd idle sound both when the engine is cold and warmed up. It doesn't happen all the time, just once in a while. You will hear it run nice and smooth for the most part, I'm guessing 98% of the time. But once in a while you will hear it like it's missing. This might happen for about 5 to 6 seconds, then it goes away. Doesn't affect how the truck runs, just happening during idle. And ideas or something I need to look for. Thanks for any info.

 

[BudTX]

How long has it been since you changed your fuel filter?

 

[12ga diesel]

The filter thats on right now is only a few thousand miles old. But I hear this with either a brand new filter or one that is ready to be spun off and replaced and anywhere in between. That was my first thought (fuel filter) when I first started hearing it, but it was in late summer/early fall, and the filter (stock filter) was only a couple hundred miles old when I first heard it, but I didn't hear it again for quite some time after that. So I'm guessing its not something to do with the temp outside. And like I said, its nothing that hurts performance or when I'm driving the truck. Just every so often, I hear it. Since I first heard it, I'm guessing I have heard it about 10-12 times or so.

The first times I heard it, I just kinda took it as the way the Cummins idle at times.

 

[GM Guy]

I am pretty sure I heard the same thing out of my boss' truck today, 03 HPCR 3500 QCLB DRW Cummins 6spd 4wd. it sounded a little chuggy and lopey for a bit, then it cleared right up.

filter is also only a few thousand old.

 

[hoot]

Mine does the exact same thing every so often. It goes away and comes back for short periods of time. No issues, no engine light. I'm thinking it may be fuel related.

 

[12ga diesel]

That's kinda what mine is. Every so often I'll hear it. But I haven't heard it in over 2 months I bet now. Exactly how you put it hoot, every so often, just comes and goes, no CEL or performance issuse.

 

[BigBlueChevy]

You may find this funny but clean up your grounds and see if the same thing happens. Electronics are simple, they either power on (I) or power off (O) to do there job. If somewhere along the line there is a brief "skip" in that operation, it can cause anything to happen.

My mothers 2007 Chevy Malibu with less than 37,000 miles on it had the radio change stations on its own when you shut the car off every now and then. During a routine maintenance, I pulled the grounds, polished them all up, and then gave them a generous coating of Anti-ox paste. Believe it or not, after that the radio has never once changed without her telling it too.

 

[jlefeve]

03 Cummins Modified

I experience this chugging quite often, usually when it goes to high idle and it clears right up i am running a 2003 Cummins with 4in turbo back exhaust with no muffler or converter, ats exhaust manifold, upgraded turbo, banks big head, banks intercooler and banks six gun with speed loader I am pretty sure there is nothing wrong with it

 

[12ga diesel]

You may find this funny but clean up your grounds and see if the same thing happens. Electronics are simple, they either power on (I) or power off (O) to do there job. If somewhere along the line there is a brief "skip" in that operation, it can cause anything to happen.

I will have to try that Jamie. Looking at them, they could benefit from being cleaned. Like you said, something simple like the grounds not being clean could cause it.