Whining strange sound!

[Christian]

Hi! my first post here.

Chevy Tahoe. Lt, 01, 39K miles.

Strange whining sound that increases with speed, had a chevy-mechanic drive it and said it was the tires ( mickey Thompson).
had engine and Dif oil-changes.
This sound started about a month ago. its not disturbing but irritating because I cant really locate it, sounds as if its coming from under the car.

thanks Christian

 

[Hotshotjas]

Do you just get the sound when you are giving it gas?

 

[AZSCTACO]

I'll take a guess......Check the rear differential......Check the U-joints and drive shaft as well. Rear diff can whine/hum if the the backlash is out of whack.

 

[Christian]

Do you just get the sound when you are giving it gas?

Hi!

Yes pretty much so I recon, either way it gets worse when I give gas and the more the higher the pitch.
Frankly its not all that disturbing, its not like its unbearable or anything, more of an irritation and Im also curious to what it is.

thanks Chris

 

[AZSCTACO]

Is a constant whine that increases with the speed of the truck or does it change with the rpm's???? Like when it changes gears, does the whine drop as well???

 

[992door]

Have you checked to see if you have an exhaust leak.

 

[Christian]

Is a constant whine that increases with the speed of the truck or does it change with the rpm's???? Like when it changes gears, does the whine drop as well???

It changes with speed, low speed, low whining, high speed and its high pitched.
took it down to a mechanic the other day and he said its the tyres making the sound, well some tyre does make whining sounds, Cooper does but Im not too sure about this

best Christian

 

[Christian]

Have you checked to see if you have an exhaust leak.

Hi!

No not yet but that was my thought as well, in bending down trying to listen under the car, its almost impossible to hear where its coming from.
If it was the exhaust? does the sound alter in pitch with speed, more gas?

 

[AZSCTACO]

I don't think its an exhaust leak.......thats more of a ticking then a whine

 

[992door]

I don't think its an exhaust leak.......thats more of a ticking then a whine

Yea that is true

 

[992door]

Does it do it when it is just sitting there running or is it just when you are driving it?

 

[Christian]

Does it do it when it is just sitting there running or is it just when you are driving it?

Good question! no, only when driving.

 

[AZSCTACO]

Good question! no, only when driving.

Then it is definitely drivetrain related. I still say driveshaft/u-joints or the rear end backlash is out of whack. Get it checked out and keep us posted so you can tell me I was right ...lol

 

[AZSCTACO]

Might want to check to make sure they put the right differential fluid in the rear. If it doesn't have the additive needed...it can cause chatter/strange noises from the rear.

 

[Christian]

Then it is definitely drivetrain related. I still say driveshaft/u-joints or the rear end backlash is out of whack. Get it checked out and keep us posted so you can tell me I was right ...lol

Ive got it booked with a Chevy mechanic tomorrow whos going to look at it, ( had dif oil change only two months ago)
Ill let you know of the outcome.

thanks Chris

 

[Christian]

Hi! well heres a little update!

Took it down to the chevy mechanic who is dead certain its tire-noise ( Mickey Thompson Baya-ATZ tyres), well I thought they were good tyres? bloody expensive anyway.
He also informed me I might have a bad CAT ( exhaust ) which possibly? could cause the whining noise, only possibly though.

Lets say Im cruising at 50mph, if I take my foot OFF the accelerator, the whining is still there.
Does this indicate something?

best. Christian

 

[08Hoe]

I have the same problem. This is being caused by the exhaust and something to do with harmonics. They have ordered a part they call a "band" that they will install on the tailpipe and move it along the length of that pipe until the sound stops.

 

[Christian]

Thanks a lot for your reply. Weird thing! the harmonics? you mean a sound right? that shouldnt be there.
Im gonna look into this and this band youre mentioning.
In any event its not something dangerous that can happen then is it?

thanks again.

Christian

 

[08Hoe]

its not dangerous, just a pain in the ass. If your dealership cant find the issue, have them call my dealer - Graff Chevrolet - 989-684-4411 and ask for service. Have them ask about the issue and for the TSB#. My dealer has fixed a few they said already.

 

[mullinax5630]

noise

it is a long shot but if you don't get it fixed check the belt not a/c belt the other.sounds funny but i had some noise bought a new belt and installed it noise gone.just a thought.