What Is This Ringing?

BlancoSilverado · March 23, 2020

7 minutes ago, truck_newbie said:

I haven't seen any recalls on the idler pulleys for the 6.2 but i'll bring it up to the tech when I take it in. Thanks.

I would say do what @FishHuntRepeat said, pull the belt off and see if it still makes the noise. at least you can narrow it down.

truck_newbie · March 23, 2020

19 minutes ago, FishHuntRepeat said:

I can also put the truck in gear with foot on the brake and blip the throttle to get it to make the noise...kind of a quick power brake. I will try and get a recording of it. i thought about taking the belt off and starting it to see if the noise was still there, my thought would be to narrow it down to idler, ac compressor or something that the belt is spinning. Hopefully i'm not sending you in the wrong direction but the noises seem to be the same to me.

I have done the brake-throttle before. If memory serves me right, I only hear the squeak when I do that. Don't worry about leading me down the wrong path , at this juncture, I will take any suggestions.

I'm curious, did you or your friend do any modifications to your truck before or after you started hearing the ringing? I'm trying to do a compare and contrast to see if the problem can be isolated that way. The only modification I have done to my truck drive-train wise is install a cat-back exhaust. So far, this seems to be localized to the 6.2 w/10 speed unless someone with a 5.3 chimes in and says otherwise. To me, this points to a very small dppm on a part/assembly that is causing this or else this thread would be blowing up with multiple 6.2 owners complaining about the same thing. My truck was built on 6/7/19 at Plant G if that helps.

Taking it to the dealer tomorrow and will play the recording for them. My first priority will be to get them to acknowledge the ringing. Will let you know how it goes. Thanks for the inputs, I appreciate it.

truck_newbie · March 23, 2020

7 minutes ago, BlancoSilverado said:

I would say do what @FishHuntRepeat said, pull the belt off and see if it still makes the noise. at least you can narrow it down.

I'm taking it to the dealer tomorrow. If it comes back with "can't reproduce your issue", I'll try this.

FishHuntRepeat · March 23, 2020

No modifications and has done it since day one. My friends truck has the factory installed cat back and same noise. When I took it to the dealer they had other trucks on the lot that had the same noise, they opened a case but I have never heard anything back. Good luck tomorrow maybe you can gain some traction

ILSilverado · March 25, 2020

On 3/22/2020 at 1:24 PM, truck_newbie said:

Alright folks, one last attempt. This time around, I recorded it with the mic outside the truck which I think is clearer. Previous recording was done from inside the cabin. As before, it's more discernible with headphones. Please give it a listen if you can. I appreciate any input. Thanks.

I hear it sounds like a spark ping to me

truck_newbie · March 25, 2020

16 hours ago, ILSilverado said:

I hear it sounds like a spark ping to me

That thought crossed my mind too. It makes sense when looked at in isolation. However, when I considered all the other factors, it wasn’t adding up to pinging being the culprit. This is the flow I went through:

1. I have tried the whole fuel spectrum (except race fuel) and the ringing still exists.

2. From what I know, if pinging will happen, it will happen during increased load. The ringing that I’m experiencing only happens during light load. So far, I have not heard it happen during medium to heavy acceleration either from a stop or while moving. It only happens during light throttle while cruising.

3. If you listen closely to the clip, you will notice that when the ringing starts, about 0.5s in, there is a clunking sound then the ringing gets a little louder. To me this is the real clue. Whatever made that clunking sound is what is causing the ringing. I doubt that clunk came from the engine though or else it would be pretty audible during idle.

truck_newbie · March 25, 2020

On 3/23/2020 at 6:34 PM, FishHuntRepeat said:

No modifications and has done it since day one. My friends truck has the factory installed cat back and same noise. When I took it to the dealer they had other trucks on the lot that had the same noise, they opened a case but I have never heard anything back. Good luck tomorrow maybe you can gain some traction

So I got my truck back today. They were not able to reproduce it and I was not allowed to go on a test drive with the tech because of the virus. They also didn’t listen to the audio clip. Ironically, this would have been the perfect time to debug this with the tech because the roads are pretty empty. Oh well. They told me to bring it back once everything returns to normal to go on a test drive with a tech. On the bright side, they fixed my 3 recalls.

What’s interesting is, the loaner I got was a new 2020 SLT 5.3 w/8-spd. It made the same noise though it wasn’t as loud as mine. So we can rule out the 10-spd and perhaps the 6.2 engine itself. Whatever the issue is, it has to be a shared component between the 5.3 w/8-spd and 6.2 w/10-spd trucks. I honestly didn’t notice this ringing when I first got my truck. I suspect it was always there, like the loaner but it just got louder over time to the point where I could readily hear it from inside the cabin or with the windows down even with an exhaust.

My next steps are to try to debug this a little further. The first thing I plan on doing is getting the truck on a lift, pedal to 40mph, get the ringing to happen then listen for the source starting from underneath the truck. I suspect the ringing requires a small amount of load in order to occur so I might eventually get it on a dyno and repeat the process.

We shouldn’t have to debug our own vehicles whilst under warranty but I guess this is the card we have been dealt. Oh well.

FishHuntRepeat · March 25, 2020

Thank you for the update, the weather is starting to clear up a bit here so I will start some investigating also

ILSilverado · March 26, 2020

Try some runs in awd only. Only then can you rule out the jingle issue.

Edited March 26, 2020 by ILSilverado

truck_newbie · March 26, 2020

5 hours ago, ILSilverado said:

Try some runs in awd only. Only then can you rule out the jingle issue.

Yep, did that too. I followed the "jingling jingling" thread for a while and was convinced it was the same issue just manifesting a little differently. I tried the 4wd test that was recommended as a fix. Ringing was still present, didn't change one bit.

ILSilverado · March 26, 2020

6 hours ago, truck_newbie said:

Yep, did that too. I followed the "jingling jingling" thread for a while and was convinced it was the same issue just manifesting a little differently. I tried the 4wd test that was recommended as a fix. Ringing was still present, didn't change one bit.

then most likely it is Engine related.

truck_newbie · March 27, 2020

4 hours ago, ILSilverado said:

then most likely it is Engine related.

That would be a real bummer. We will see what the troubleshooting reveals. Thanks for the help. I will update this thread if i find anything new.

ILSilverado · March 27, 2020

19 hours ago, truck_newbie said:

That would be a real bummer. We will see what the troubleshooting reveals. Thanks for the help. I will update this thread if i find anything new.

Maybe not could be something very simple too.

Muskyhunter777 · July 6, 2020

I had the same problem and noise...had taken it to the dealership for 100 other reasons along with this one and they found out what it was supposedly. It came down to the fuel pump and the hose going into it making a chime noise. It hasn’t made the noise since they’ve changed it. Hope this helps.