I have owned for the last year a BMW Series 3 Estate. After about 300 miles, it developed a strange humming noise which sounds like is coming from the passenger side footwell area.

 

I can only describe it sounding like 'dum dum dum dum',  and is only there 65-75mph, or just under 2000 revs. It is not noticeable at any other speed that i can hear.

 

It has been back to BMW and two mechanics have been out and heard it. They said sounds like a rotation noise, and put a donor set of wheels on, took it out but the noise is still there, so had mine put back.  They then said it was the door seals as apparently a common issue and there had been a rattle on the door, but all four replaced and noise still there. (Though rattle gone lol) 

 

Then COVID stopped play, and its recently been back for 4 days, they drove it once around town and heard nothing, so sent me on my way (didnt obviously get to the speed depsite knowing this and mileage suggests they hadnt been far).

 

Soon as i got in it and drive on major roads, the noise is there, and my god its annoying and has got louder since it first began to the point i turn the radio up to drown it out.

 

I did notice when weight in the boot (suitcases) it also became alot louder

 

They've not had it on ramp to check anything, and im at the stage of pulling my hair out. Took it to another garage to check tyres again and all perfect, and balanced perfect, allignment all fine,  they suggested a wheel bearing may be faulty but its not tyres.

 

Car now has 16500 miles on as i do motorway miles with work, so spend a lot of time on the road, hence it has become unbearable. Passengers can hear it also and comment its loud and not road noise as when under the speed it comes, the car is quite and perfect.

 

Anyone had similar issue?