Whistling Noise

SMKN LS1 · April 9, 2015

Dealer replaced my center roof marker light assembly for this issue. The tech used the "tape" approach to isolate the source. I'll keep an ear open to see if it's truly fixed.

utmikeg · April 20, 2015

Enthusiast, can you confirm your whistling issue has been resolved? I just sent my truck into the shop this morning for the second time trying to fix the issue. They tried to tell me it was the mirrors. Even folded in it makes that noise. My noise seems to be coming from the front passenger windshield area.

SMKN LS1 · April 20, 2015

utmikeg - which "enthusiast" are you referring to?

In my case, the replacement center marker light on the roof seemed to cure it. My noise also came from the front windshield area. Having a passenger in the truck allowed me to isolate the location. My wife said it sounded like it came from the driver's side. I said it sounded like it came from the passenger side. So, it must be in the middle lol!

utmikeg · April 21, 2015

Sorry for the confusion everyone. I was referring to you SMKN LS1. Thanks for the update. When you say center marker light, are you referring to the optional roof lights? Googling this doesn't bring a very clear answer to what this is. My truck doesn't have roof lights. My wife and I did the same troubleshooting you did and my "whistling" appears to be coming solely from the windshield passenger side only. I even let my wife drive and I sat in the passenger seat. I observed it coming form the passenger side as well. It's very difficult to isolate exactly where it's coming from which makes this so difficult to pin down.

SMKN LS1, did your dealer replace the entire windshield as well and the whistle is now gone?

SMKN LS1 · April 21, 2015

Utmikeg - yes, I was referring to the optional roof lights. These came standard on our 3500 series. Our windshield was not touched during the repair.

If it helps, our whistling noise was identical to the sound recorded on the video that a previous poster attached in this thread. If your noise sounds different, then the solution may be something else (i.e. windshield molding, on star antennae, mirror?) Good luck and I'll post here again if the noise returns.

utmikeg · April 21, 2015

Thanks SMKN LS1. I drive the 2500 High Country. My noise is the same as the video and happens anywhere around 65-75 MPH. As I mentioned before, my truck is at the dealer so we'll see what they come back with. Thanks for the input.

mwweiss · April 22, 2015

My whistling problem is solved!!! The dealer didn't help or find it. As it turns out, the radio antenna caused the problem. I taped everything off attempting to find the source---window, roof joint, fenders, mirrors, etc. I found that the sound didn't change with moving the mirrors or by rolling down the windows. That was the key--if the sound didn't change after the cab was depressurized by rolling down the window(s), the source was outside the cab. In a final test, I removed the antenna and taped over the hole. Success. I untaped the hole and still success. Forget the dealer, I purchased an after-market stubby antenna and my ride has been quiet ever since. The **** dealer never did contact me after driving in and discussing the issue with them. It seems this type of problem wears you down and eventually people either learn to live with the defect or settle for the excuses they're given. I'm happy this is finally resolved and I can enjoy the vehicle even though it took me several weekend test drives and a few hundred miles of driving to diagnose (it was tough to find an area where I could drive high-speed without too much traffic or too much enforcement). Thank you to all who offered suggestions and their own experiences.

utmikeg · April 22, 2015

Thanks for the tip MWWEIS. I will see what the dealer comes back with. Coincidentally, because the factory antenna hit my garage door, I replaced it with a shorter version the day after I bought it. I still had the whistling with the shorter antenna. If it comes back with the sound, I will remove the antenna completely and test it. It may require a different antenna altogether. After reading this thread it seems there are no consistent resolutions to this whistling issue.

mwweiss · April 23, 2015

I suspect you'll find your short antenna is the source of the whistle. I tried two different after-market antennas and the short one without the twists on it whistled in the same manner. I settled on this one http://www.antennax.com/p-5106-gmc-sierra-2500-2007-2015-5-inch-shorty-antenna.aspx

Good luck!

utmikeg · April 27, 2015

Hello Everyone,

It looks like MWWEISS was correct. I got my truck back on Friday and the dealership discovered it was indeed the antenna. My service agent said there's now a bulletin in GM's system about this issue.They are issuing new antennas to solve the problem. They didn't have the new antenna is stock so they left the old one on so I could get radio reception. I tested the antenna on the way home and stopped half-way there to remove it. The whistle was there with it and gone without it. Thanks for everyone posting their experiences on this forum. It's helpful to have other owners share and offer help.

Thanks,

Mike

junkyardz · April 27, 2015

I lucked out and completed my antenna delete not even trying to fix the whistling noise my truck had intermittently. It's super easy and you can use a plug from the rear inner bed sides to cover the hole in the factory antenna cowl cover. I simply disconnected the antenna and ran it inside the engine compartment along the inner fender. No change in reception quality, no whistling and a clean shaved antenna look.

Jeremy Ehrlich · May 16, 2015

Hello all, new to the forum, but wanted to throw some info in on this topic. I purchased a 2015 GMC HD Crew with the SLT package, 6.0 gas motor. 40 miles on the odometer, brought in special from another dealer for me. Drove off the lot, some type of whistle noise, or humming if you will. Sounded like an off wind recorder player. Thought, oh it's windy so I'll see how it goes. Well the noise is there, at any speed or wind, or high speeds etc. Took it to the dealer at 500 miles. They told me, it's something you'll have to live with, it's a normal drivetrain issue/noise. well at around 1k, I was sick of the noise. I did research on the forums right at 45 miles. There was a myriad of info about what dealers were trying, to no avail. I don't have maker lights on roof, no heavy duty mirrors, yes XM antenna, but nothing else, oh and no sunroof. Un happy with the dealer telling me I have to live with this noise, I took it upon myself. Yes a 55k truck should not whistle like a 76 chevy. Also before buying this truck, I drove 8 gmc/chevy variants, both gas and diesel. No noise of this kind whatever. So my boy and I took a roll of painters tape and took it upon ourselves to figure it out. Besides, it sounds like numerous people on the forum kept leaving their truck with the dealer as they attempted to figure it out, and frankly I need my truck so that wasn't an option. Besides, the dealer that said it was drivetrain said, we'll keep it till the next morning and drive it good, then we'll see. The dealer literally kept it for two hours, checked fluids and then said it's normal.

Started taping off all body panel gaps from the grill, we did not seal grill area, but body panels. As we went along noise was still there. Once it was all taped off, noise gone. So we step by step started taking tape off. Noise came back when we took the tape off the hood, where it meets the headlight, grill area. So we watched it. As the hood bounced with road smoothness, the whistle got louder, changed pitch, so on and so on. So, painters tape came off, because it was tacky looking on such a nice truck. Clear packing tape went on and through two weeks of driving, all weather, all speeds all types of roads, no noise. Upon closer look. The fenders were not aligned where they meet the A pillar. Passenger side had 1/16 gap, Driver had 1/2 inch gap. Hood was also misaligned over a 1/4 inch at the bracket, so over 3-4 feet it made about 1/5 inch difference.

Took it back to dealer and asked them to re-align body panels. They laughed and said, we already told you the sound is normal, but if you really think that's the problem we can look at it. He then asked if the truck was with me, said yes and that it's easily noticeable, he refused to come out and look at it. Mind you this was the selling dealer. Un-amused by their desire to correct the problem, I traded the truck that afternoon. It was very nice, but a bummer. Remember techs of today are not old school where they listen and look. If the computer says its fine, then that's what you get. Don't be afraid to save yourself ninety trips to the dealer and having those same techs take your truck apart and put back together, because they are probably using the same amount of care in doing so. My wife said I should share this info with everyone so that if you love your truck but don't love the whistle, excluding diesels, then give it a try. It may be something different then what I found, but it's worth a shot so you can go in with all the info to the dealer.

Drive safe

ADB0627 · May 22, 2015

Thank you 2500/3500 section! I can also confirm that removing the am/fm radio antenna resolved with whistle sound. Thank god!!! After four trips to the dealer and hours of frustration the whistle is gone!

Edited May 22, 2015 by ADB0627

Jason Diebold · June 24, 2015

My issue was when some of the air vents were closed. Try opening slightly the air vents and see if it goes away?!?!

Ivy Harper · June 24, 2015

I have a 2015 3500 Denali with a moon roof. I have around 4K miles and now have a whistle that sounds like it is coming from the roof. In the mornings, when it is cooler, I do not have the problem. When the temps rise, it seems to start and get louder. Any input will be greatly appreciated.