2008 Ram 1500 SLT 4x4 5.7L

My truck has been making an intermittent squealing/whistling noise for a while now, probably two years. It sounds like a quiet brake squeal, it actually often (but not always) starts when the brakes are applied, but even after the truck has come to a dead stop, it continues. I don't mean it continues for a second and I'm just THINKING I'm stopped when I'm not, it will continue on for seconds or even minutes.

I don't hear it at normal speeds, just when going very slow or stopped. Sometimes it starts up as soon as I start the truck and put it in gear. Sometimes it doesn't happen at all for weeks, then it does it again for a while. It will sometimes be making the noise, I get home, park in the driveway with the truck in park, it still makes it. I turn the truck off, it still makes it. I turn the radio off, it still makes it. When I then open the door to exit the truck, it stops. I thought maybe the speakers were picking up alternator whine or something, but it doesn't cycle up and down, it's just a steady sound, plus it does it even when the engine is not running sometimes, as mentioned above. Not loud, just there. No other issues related, electrical, lights, stalling, hiccups, nothing. Just the sound. No rhyme or reason or pattern I can discern.

I have noticed if I have the truck running with the hood open, if I turn it off, I will hear a kind of hissing noise for maybe 10-15 seconds, like pressure being relieved from somewhere, but I can't track that down, and I don't know if that is normal or even related. It doesn't sound the same, but thought I'd mention it.

The dealer had the truck today to check this and a couple other issues, They said the front pads and rotors need replaced. OK, I'll do that, but it's not the cause of this noise.

I thought maybe a vacuum or air leak somewhere, the dealer said it can't be that or the computer would detect it and throw a check engine light. They said they'd check some more tomorrow, but I can tell they aren't too hopeful or enthused.

So I am stumped here. Has anyone else ever experienced this or have any suggestions?

Thanks guys.

 

If you still hear the noise, even with the engine off, and it only stops when you open the door, it has to be related to one of the system that is still powered at key-off, and shuts down when you open the door. The radio springs immediately to mind for that..... not sure what else is still energized at that point.

 

That is kind of what was coming to my mind as well, as the radio volume **** has been very erratic and touchy. Maybe there is something electronic-wise inside the radio causing that issue rather than mechanical and it's causing the noise as well. The radio is scheduled to be replaced with a new one in a few days under the max-care warranty, so if that solves the issue, I'll report back for reference for others.

Thanks for reading my post and for your input.