GM Truck Club Forum banner
1 - 18 of 18 Posts

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #1 ·
Hey all,

just bought a lovingly used 2003 Yukon Denali with 180k on it. I had two mechanics look it over before sale, and besides some goofy 22” rims and tires which DONT BELONG on that vehicle, it was sound.

I just drove it 500 miles through the mountains of Utah down to Phoenix, pretty sweet ride.

I should mention I’m hauling a 4000 pound tiny home behind it and at some times I didn’t even know it was back there.

only “problem” I’ve noticed and need help on is a loud “whistling sound” when I depress the accelerator. I cannot locate exactly where it is coming from, if I hit the gas I hear it, and it goes away about 1-2 seconds after I let off the pedal. I also noticed on a really bumpy road I sometimes hear it when the vehicle dips into the curve of the road. The vehicle has performed top notch, all fluids and temps are in range, my thought is something is either vibrating or rubbing?

I thought I would come here and ask you guys, maybe it’s a normal sound for that motor/vehicle.

I’ve never owned a “big V8” before so I’m unfamiliar with their idiosyncrasies.

I’m in Phoenix and I’m hauling all the way to Key West, so if the is is a “do or die” issue, someone please speak up.

ill be here for a week.

thanks everyone, here is a pic of “Brutus”

Wheel Tire Sky Vehicle Car
 

·
Registered
Joined
·
16,450 Posts
tiny, welcome to the site.

From your description, it's air being pulled into the engine.
Do you know what a cold air intake is?
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #3 ·
tiny, welcome to the site.

From your description, it's air being pulled into the engine.
Do you know what a cold air intake is?
Hi Ray,

I think it’s something like a ram scoop or the like, isn’t it supposed to be for performance, and Isn’t there a hole in the hood for that?

sorry I’m mechanically smart, but I’m a general car idiot lol
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #7 ·
Look under the hood, do you have something that looks like this:

View attachment 170334
Nothing like that under hood, here is a photo of the filter, also i revved the engine to 3500-4K rpms while idle, no noise except standard engine noise. Belts look good no fluids underneath, so whatever this is only happening under load ….

mystery continues

Hood Automotive design Textile Motor vehicle Font
 

Attachments

·
Registered
Joined
·
16,450 Posts
Ok nice, I assume there is a cover for the filter.
If it appears to only happen while moving, there is one other source of noise. Does the roof rack have the crossbars?
They can cause a whistling noise.
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #9 ·
Ok nice, I assume there is a cover for the filter.
If it appears to only happen while moving, there is one other source of noise. Does the roof rack have the crossbars?
They can cause a whistling noise.
Lol yea it has the full assembly, I took it out to look at the filter. Roof rack has roof bars , one cross bar in front and one in back, doubt those bars are connected to the noise, or it would be all the time not just when accelerator is depressed. The noise is absent when my foot is not on the gas pedal.

Car Plant community Vehicle Hood Motor vehicle
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #11 ·
Ok so I paid $200 to get the fluid changed, and they want me to drive it for the weekend to see if the “gear whine”) decreases. If not it’s $1500 Monday for a used front differential installed. I was surprised no one knew what if was here. Interesting. I would like to drive it to Florida and ignore the whine, but I know that is not smart for me or the vehicle! Anyway it is what is, and hopefully this will fix the vehicle. For future people searching, if you hear a whine when your accelerate and it goes away after , CHECK THE DIFFERENTIAL for metal shavings. Hope it helps someone in the future!
 

·
Registered
2001 Suburban 5.3L, 296k miles
Joined
·
1,647 Posts
Your description of the noise was not accurate so the possible sources were also inaccurate. A whistling noise is not the same as a whining noise.
We'll, you found the problem and that's a good thing.
The bad thing is, once the differential whines, the pinion bearing preload is already lost due to worn bearings. Its not going to fail right away esp now it has new gear oil. But the whine is very annoying. I drove my 2001 suburban for about six months before I decided to change the differential bearings.
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #13 ·
Your description of the noise was not accurate so the possible sources were also inaccurate. A whistling noise is not the same as a whining noise.
We'll, you found the problem and that's a good thing.
The bad thing is, once the differential whines, the pinion bearing preload is already lost due to worn bearings. Its not going to fail right away esp now it has new gear oil. But the whine is very annoying. I drove my 2001 suburban for about six months before I decided to change the differential bearings.
Bazar

I agree I had no clue what the noise was, are you saying I can drive it to Florida like this, I’m still hearing the “whine” it didn’t go away, to be honest I was just cranking the tunes , I heard it on between songs and then started listening more intently.

also keep in mind I’m hauling a 4700 pound tiny home. I’m not expecting you guys to have all the answers, but it’s either run with the new fluid, or plunk $1500 more down Monday.
 

·
Registered
2001 Suburban 5.3L, 296k miles
Joined
·
1,647 Posts
Is the Denali a full time all wheel drive or you can select 2hi, 4hi, auto, 4lo?
If you can tow on 2hi, the rear diff will be driven and the front will not be driven and will just free wheel, so no danger of grenading the front diff.
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #15 ·
Is the Denali a full time all wheel drive or you can select 2hi, 4hi, auto, 4lo?
If you can tow on 2hi, the rear diff will be driven and the front will not be driven and will just free wheel, so no danger of grenading the front diff.
Full time AWD to my knowledge, though I’ve never been able to determine exactly, there are no lo/hi switches on board anywhere.

I was told this model can’t be “flat towed” and that’s usually an AWD limitation.
 

·
Registered
2001 Suburban 5.3L, 296k miles
Joined
·
1,647 Posts
Full time AWD to my knowledge, though I’ve never been able to determine exactly, there are no lo/hi switches on board anywhere.

I was told this model can’t be “flat towed” and that’s usually an AWD limitation.
I drove with a whining rear diff on my 2001 for about six months. It never got worst. Drove it to Atlanta and back so many times (500 miles round trip)
It was just annoying until I finally decided to replace it with a used one, then the used one also started whining. I replaced all the bearings on the used one and I still drive it and now has 295k miles.

With new oil and with correct level with no leaks, it shd last. I'll drive it around short distances and see if it gets louder and turns from whine to roaring noises. If it starts to roar, stop driving it.
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #17 ·
I drove with a whining rear diff on my 2001 for about six months. It never got worst. Drove it to Atlanta and back so many times (500 miles round trip)
It was just annoying until I finally decided to replace it with a used one, then the used one also started whining. I replaced all the bearings on the used one and I still drive it and now has 295k miles.

With new oil and with correct level with no leaks, it shd last. I'll drive it around short distances and see if it gets louder and turns from whine to roaring noises. If it starts to roar, stop driving it.
Thanks for the vote of confidence.,

it has new oil and the whine is just that… a whine. Only at high speeds and only when the accelerator is depressed. I kind of hoped that the whine would have gone away with the new oil,

worse comes to worse, I could have it changed out in Florida… if I make it there.
 

·
Registered
2003 GMC Yukon XL Denali 1500
Joined
·
12 Posts
Discussion Starter · #18 ·
So if anyone else has had differential’s issues (whines, noises) I would be curious how it was handled. I’m still trying to make a decision on replace/go with new oil.

Thanks everyone
 
1 - 18 of 18 Posts
Top