Weird noise after wheel replacement

[Pano6]

I changed the rims on my 640i GC from 19" runflats to 20" summer performance tyres (non-runflat), and ever since taking it from the wheel shop I noticed whenever the car is under moderate to hard acceleration there is sound that I can only describe as a mix between air passing through a partially open window and a rubbing noise.

I have tried revving the engine in neutral and no noise is made.

This ONLY happens when driving the car and hitting the gas kinda hard.

My initial thoughts was that it's the rear tyres due to weight transfer, however the sound is in my opinion very clearly coming from the front driver side (US car, left-hand side).

Does anyone have any idea what this could be? A look at wheel arch doesn't indicate anything rubbing, nothing on the undercarriage, plenty of space around the wheel arches. Even took it back for another alignment as it was pulling a bit to one side, they fixed that but the sound remains.

I'm honestly stumped. They didn't seem to be able to figure it out either.

[Havy]

Are the tires with running direction? Wich brand are they. Check the pressure.

[Pano6]

Originally Posted by Havy

Are the tires with running direction? Wich brand are they. Check the pressure.

I have done more research and it looks like this is a common problem on BMWs. Quite a few people have mentioned it, and yes, it sounds like an engine problem. There is even someone here who made a thread about the same noise: https://www.6post.com/forums/showthr...6#post22895006

Thing is, when you research and test yourself, you realise this isn't an engine problem. It's a wheel problem.

People who solved this solved it by doing things like having BMW sand down brake pads, replace bearings and more.

Nobody seemed to have a fully clear answer though on what caused it and a definitive fix.

In my case though, I think I can say with 100% certainty this is a problem caused by how the wheels have been put on. But I can't figure out what causes the noise or how to explain this to the wheel people to have them fix.

Any ideas??

[Pano6]

It seems to me like it's likely a bent rotor shield or a rock stuck around that area. Maybe they knocked it when replacing the wheels, or the increase from 19's to 20's has caused a problem in that area?

[Opie55]

Do you still have the 19s? If so, put them back on see if the noise is gone. New wheels, so long as they are not rubbing anywhere, will not induce a noise that was no there before. So you need to carefully investigate for rubbing first. Especially since the noise only happens when you accelerate hard. When you accelerate hard, you are changing the configuration of the suspension, and thus the relationship of the wheel/tire to the car.

[Pano6]

Originally Posted by Opie55

Do you still have the 19s? If so, put them back on see if the noise is gone. New wheels, so long as they are not rubbing anywhere, will not induce a noise that was no there before. So you need to carefully investigate for rubbing first. Especially since the noise only happens when you accelerate hard. When you accelerate hard, you are changing the configuration of the suspension, and thus the relationship of the wheel/tire to the car.

Unfortunately, I don't have the 19's anymore. However, you might be right as I was told the suspension arms are damaged and need to be replaced.

Is it possible they could be causing the noise?

[thebmw]

Any chance the new wheels are barely hitting the brake caliper?

[thebmw]

Which style wheels did you have before and what style did you change to?