Very quiet droning in 2H

[1337logan]

Stock 6.7.
Since I picked it up new, when I'm driving on the road I can detect a very quite/low droning when my foot is on the gas, but it immediately stops when I take it off. The pitch doesn't change with speed. And is only really detectable around 1200 rpm. I can't tell if it's a transmission drone, or just the exhaust/engine. It's so well insulated it's hard to tell. All gauges/messages are normal. Trans and engine temp are fine. Probably nothing.

Thoughts?

 

[Whyte Rhyno]

is it loud enough to record?

 

[davidb1841]

Some guys have reported tranny whine.....but in a 6.7 its not really detectable

 

[1337logan]

is it loud enough to record?

I'll see if I can get something, it's more of a certain 'tone' than a 'noise' if you get what I mean. I really wonder if it's just the actual engine/exhaust. I'm an engineer, so I tend to over analyze everything ?

 

[WhiskyThrottle]

Stock 6.7.
Since I picked it up new, when I'm driving on the road I can detect a very quite/low droning when my foot is on the gas, but it immediately stops when I take it off. The pitch doesn't change with speed. And is only really detectable around 1200 rpm. I can't tell if it's a transmission drone, or just the exhaust/engine. It's so well insulated it's hard to tell. All gauges/messages are normal. Trans and engine temp are fine. Probably nothing.

Thoughts?

Did you ever sort this out? As you said it's only detectable at a certain RPM and not very loud. I would think it could just be a couple pieces close together and one of them resonates a little at that one freq. as opposed to some real problem.

 

[PapaRaptor]

I'm an engineer, so I tend to over analyze everything ?

Explains a lot

Teachers are worse......................

 

[1337logan]

Nothing sorted out. Still detectable but nothing really seems to be 'wrong', i.e., no odd smells, no high temps, shifting is smooth and crisp.

 

[Trämör]

Stock 6.7.
Since I picked it up new, when I'm driving on the road I can detect a very quite/low droning when my foot is on the gas, but it immediately stops when I take it off. The pitch doesn't change with speed. And is only really detectable around 1200 rpm. I can't tell if it's a transmission drone, or just the exhaust/engine. It's so well insulated it's hard to tell. All gauges/messages are normal. Trans and engine temp are fine. Probably nothing.

Thoughts?

I got the same thing on my 7.3L. Exactly at the same RPMs, more pronounced in 8th gear at 35-45mph. Quiet droning has a bit of a slow wave pattern I’ll say...

 

[1337logan]

I got the same thing on my 7.3L. Exactly at the same RPMs, more pronounced in 8th gear at 35-45mph. Quiet droning has a bit of a slow wave pattern I’ll say...

Yeah, I can't seem to find anything wrong with it. But it feels/sounds like it's coming from the middle-rear of the cab. Any ideas?

 

[Trämör]

Yeah, I can't seem to find anything wrong with it. But it feels/sounds like it's coming from the middle-rear of the cab. Any ideas?

I've been trying and investigating too, but it's so mild, i can't even properly record a video or clip of it.
I will say I discovered the exact same slight sound pattern when the truck is off and standing still, leading me to believe this is somewhat related to electrical/alternator/...
You need good ears to tell, but, here's what I did and twice I was able to hear the sound. You have to be in a quiet spot (i did it in my garage).
- Unlock the truck, get in, close the door, and just sit in the driver seat, without doing anything else. Not starting it, not pushing any buttons.
- If it's absolutely silent (think of it as if you're trying to meditate in your truck, if that's your thing), you will be able to hear the slight wave-like electric droning.
- If you can't tell at first, you will be able to after about 10-15min, when the truck goes into deep sleep again, because that's when the sound goes away. So you gotta sit there for a bit.

That sound and wave pattern is exactly the same as the one i hear when driving at those RPMs, just more pronounced.

 

[1337logan]

I've been trying and investigating too, but it's so mild, i can't even properly record a video or clip of it.
I will say I discovered the exact same slight sound pattern when the truck is off and standing still, leading me to believe this is somewhat related to electrical/alternator/...
You need good ears to tell, but, here's what I did and twice I was able to hear the sound. You have to be in a quiet spot (i did it in my garage).
- Unlock the truck, get in, close the door, and just sit in the driver seat, without doing anything else. Not starting it, not pushing any buttons.
- If it's absolutely silent (think of it as if you're trying to meditate in your truck, if that's your thing), you will be able to hear the slight wave-like electric droning.
- If you can't tell at first, you will be able to after about 10-15min, when the truck goes into deep sleep again, because that's when the sound goes away. So you gotta sit there for a bit.

That sound and wave pattern is exactly the same as the one i hear when driving at those RPMs, just more pronounced.

Interesting. Mine sounds completely mechanical and will change a little in pitch with RPMs.

 

[Trämör]

Interesting. Mine sounds completely mechanical and will change a little in pitch with RPMs.

We have a different drone then lol or maybe not. Because mines mechanical when driving. But, it matches the pattern of that sound I described in the post above, which is more electrical... who knows... I guess I just need something to keep my mind busy

 

[1337logan]

Update: I can reproduce the drone when in P, i.e., not moving. Does anyone notice this with a higher amp alternator?

 

[Trämör]

Update: I can reproduce the drone when in P, i.e., not moving. Does anyone notice this with a higher amp alternator?

Exactly my thoughts - I think this is an alternator issue