Loud humming noise when hot

[Csa7]

Hello!
I'm new to the forum and was hoping some Audi wizards could help!
I get a loud humming noise after driving for an extended period of time (Usually around an hour) it sounds like its coming from quite close to me in the engine bay. If I brake the noise goes but comes back immediately after I lift my foot, the same happens if I turn the steering wheel left or right.

Changing gear makes no difference neither does accelerating.

I think if I hit an uneven part of the road it stops for a millisecond.

If you need any more info to help me please let me know!

Thanks in advance

Chris

 

[NHN]

Wheel bearing, bush, tie rod, wheel imbalanced, variety of things could be, need to lift & turn wheels to listen for anything.

 

[Csa7]

I'll jack it up and have a shake around and see if I notice anything. Is it likely they will be problematic but only after a long period of time? I thought they would show signs even cold?

 

[NHN]

Things expand, contract so who knows what's going on, need to maybe check when cold, if nothing noticeable, get it up to heat so it happens then lift & check manually.

 

[Csa7]

Fair point, thanks for the advice

 

[billgatese30]

I've had a sticky calliper cause this. Not sticking enough to make the rotor noticeably hotter, but enough to cause a groaning noise at times. It wasn't strictly related to road speed but was influenced massively by even the slightest brake pedal pressure. A quick strip of the carrier and cleaning up and regreasing the sliding pins was enough to resolve it.

 

[Csa7]

I'll definitely be taking a look, I've ordered some wheel bearing kits anyway so will check the calipers while I'm there. Thanks for the input!