Howling noise when driving

[jeostang]

I’m getting a howling type noise while driving. I thought at 1st it was wheel bearing or tire but after further testing I don’t think it is. I can hear it while driving on the throttle, then it's louder off the throttle. No change in sound when turning, switching lanes or hard cornering. The noise goes away when shifting to neutral and coasting at idle, only comes back when shifting back to drive. It sounds likes tire or bearing or howling, just don’t think that’s what it actually it. There is a tire with low tread on the front passenger side that I’m going to replace.

[pennsiveguy]

Originally Posted by jeostang

I’m getting a howling type noise while driving. I thought at 1st it was wheel bearing or tire but after further testing I don’t think it is. I can hear it while driving on the throttle, then it's louder off the throttle. No change in sound when turning, switching lanes or hard cornering. The noise goes away when shifting to neutral and coasting at idle, only comes back when shifting back to drive. It sounds likes tire or bearing or howling, just don’t think that’s what it actually it. There is a tire with low tread on the front passenger side that I’m going to replace.

Is it howling at a steady pitch, or variable? If it varies, does it vary with vehicle speed, engine RPMs, or no particular pattern?

[The Libertine]

Originally Posted by pennsiveguy

Is it howling at a steady pitch, or variable? If it varies, does it vary with vehicle speed, engine RPMs, or no particular pattern?

OP, as noted try to narrow down the circumstances when you hear the noise or when it is more pronounced.

[jeostang]

It’s a steady sound, when letting off the throttle, gets less noticeable while on throttle, but stays steady. Mostly hear it with the windows up from the passenger side. Even as rpm drops to 1500 while off throttle sound is the same till about 1000 rpm then fades away.

[201]

Check front diff for any leaks and check behind front wheels for grease could possibly be a tear on CV boot. I had similar howling up to 2k rpm from driver side which ended up being a tear on CV boot had it replaced and noise went away

[pennsiveguy]

Originally Posted by jeostang

It’s a steady sound, when letting off the throttle, gets less noticeable while on throttle, but stays steady. Mostly hear it with the windows up from the passenger side. Even as rpm drops to 1500 while off throttle sound is the same till about 1000 rpm then fades away.

I have to think that it's something electrical, because all the mechanical stuff would increase in pitch with the speed of the engine or vehicle. Fuel pump? Changes in throttle, meaning demand for fuel, might change the way it sounded.

[1norseman]

I don't know if they salt the roads where you drive?

A while back, coming back from a ski trip, I started getting very similar sounds from the outside of the X5. Roads were pretty much empty, except for me and a salt truck I caught up with, after quite a while I passed, and then sped up again.
Not long after that, I started getting the same howling sounds, making me wonder if I had a bad wheel bearing.

Anyway, it turned out it must have been the brakes, I'm guessing a build up of salt or whatever they use to melt the ice, did something to them?!?!

I came to realize the likely source of the sound, since the howl went away when I was braking or slowing down.

When I pulled over to make sure the brakes were not overheating, I found they were warm, but not scorching. Had thin gloves on and could touch the front rotors quickly without burning the glove or my finger.

Sound was worse the faster I was driving, so I slowed down to around 60-65 and and I could hardly hear it. Lasted less than an hr.

[jeostang]

Originally Posted by 201

Check front diff for any leaks and check behind front wheels for grease could possibly be a tear on CV boot. I had similar howling up to 2k rpm from driver side which ended up being a tear on CV boot had it replaced and noise went away

I’ll check this today

[jeostang]

Originally Posted by pennsiveguy

I have to think that it's something electrical, because all the mechanical stuff would increase in pitch with the speed of the engine or vehicle. Fuel pump? Changes in throttle, meaning demand for fuel, might change the way it sounded.

It baffles me, could be something like a fuel pump, but why when I shift to neutral it goes away. I may take it to my friends shop with a dyno, an get under to try an pin point it.

[jeostang]

Originally Posted by 1norseman

I don't know if they salt the roads where you drive?

A while back, coming back from a ski trip, I started getting very similar sounds from the outside of the X5. Roads were pretty much empty, except for me and a salt truck I caught up with, after quite a while I passed, and then sped up again.
Not long after that, I started getting the same howling sounds, making me wonder if I had a bad wheel bearing.

Anyway, it turned out it must have been the brakes, I'm guessing a build up of salt or whatever they use to melt the ice, did something to them?!?!

I came to realize the likely source of the sound, since the howl went away when I was braking or slowing down.

When I pulled over to make sure the brakes were not overheating, I found they were warm, but not scorching. Had thin gloves on and could touch the front rotors quickly without burning the glove or my finger.

Sound was worse the faster I was driving, so I slowed down to around 60-65 and and I could hardly hear it. Lasted less than an hr.

Yes we have salty road, this week was the 2nd time they laid down salt.

[turboawd]

My initial thought would be a differential or transfer case whine. Does the noise change when pressing the gas, versus letting off the gas? From loading to unloading the driveline.

[jeostang]

Originally Posted by turboawd

My initial thought would be a differential or transfer case whine. Does the noise change when pressing the gas, versus letting off the gas? From loading to unloading the driveline.

Same noise just louder when off the gas.

[turboawd]

And you could be cruising down the street and pop it in to neutral, and no noise?

[jeostang]

Originally Posted by turboawd

And you could be cruising down the street and pop it in to neutral, and no noise?

Yep

[jeostang]

Had a Neighbor who is an Audi mechanic listen, he then looked at my tires, an noticed my passenger front is way lower then the rest. This is because I got the others replaced under road hazard warranty, an didn’t need to change the passenger tire. He told me to change the Front tires, 1st but in his opinion I should change all 4. So I’m going to change the front two since the one is pretty low an see what happens. I love my wheels but it sucks I can’t rotate them.

[turboawd]

Originally Posted by jeostang

Had a Neighbor who is an Audi mechanic listen, he then looked at my tires, an noticed my passenger front is way lower then the rest. This is because I got the others replaced under road hazard warranty, an didn’t need to change the passenger tire. He told me to change the Front tires, 1st but in his opinion I should change all 4. So I’m going to change the front two since the one is pretty low an see what happens. I love my wheels but it sucks I can’t rotate them.

Tires noise wouldn't go away by shifting to neutral though.

[jeostang]

Originally Posted by turboawd

Tires noise wouldn't go away by shifting to neutral though.

He was thinking the uneven tire wear causing the TC to make noise.

[jeostang]

So I decided to fill the tire with low tread to the max with about 46psi from the 36psi it was at and test drive it. The sound drastically is much much quieter, and totally gone when letting off the pedal. I then put it back to operating PSI and the sound came back. So now the question is should I order all four tires or just the front two? I'm leaning towards all four so I can keep the tread wearing evenly, and just keep the three good tires in my shed and have a rotation schedule with those once the new tires get to the same tread depth as the ones on it now??

[pennsiveguy]

Originally Posted by turboawd

Tires noise wouldn't go away by shifting to neutral though.

The way the OP described the noise, it makes zero sense that it's a tire noise. If you can't accurately describe the symptoms, you won't get a very good diagnosis.

[jeostang]

Originally Posted by pennsiveguy

The way the OP described the noise, it makes zero sense that it's a tire noise. If you can't accurately describe the symptoms, you won't get a very good diagnosis.

I described it like I heard it, and didn’t get it myself, I didn’t say it was tire noise an I had ruled it out. I just posted about the tires causing the TC to make noise due to uneven tire wear which after some research I’ve seen others had the same issues. Don’t matter anyways I figured it out.

[Russmov]

Originally Posted by jeostang

I described it like I heard it, and didn’t get it myself, I didn’t say it was tire noise an I had ruled it out. I just posted about the tires causing the TC to make noise due to uneven tire wear which after some research I’ve seen others had the same issues. Don’t matter anyways I figured it out.

Glad you got that solved. If you need to get all 4 you might as well do it at one time.

[Gkacmaz]

So I have the same noise and went to my mechanic to get it checked in my case it comes from the front differential. Brought the car to the dealer since I have extended warranty so we'll see how it turns out

Here's a Video of my issue

https://drive.google.com/file/d/1wwg...w?usp=drivesdk