[BIGW0RM]

Originally Posted by afk84

I have a humming sound after the cold start cools down and I noticed a humming sound from the engine side

That’s most likely your radiator fan winding down. Mine does that too.

[yves998]

Hi. I'm just wondering if you have any progress with identifying this noise. It seems like I'm experiencing the exactly same syndrome as yours but mine is the loudest at around 2000rpm and 35-40mph with mild throttle acceleration. It will disappear with downshift or harder throttle input.https://youtube.com/shorts/NPtiP5aDb...5kCWsSVZNhItN6

[BIGW0RM]

Originally Posted by yves998

Hi. I'm just wondering if you have any progress with identifying this noise. It seems like I'm experiencing the exactly same syndrome as yours but mine is the loudest at around 2000rpm and 35-40mph with mild throttle acceleration. It will disappear with downshift or harder throttle input.https://youtube.com/shorts/NPtiP5aDb...5kCWsSVZNhItN6

No progress yet. Haven’t taken mine in yet. But if you take yours in please keep me posted.

[yves998]

Originally Posted by BIGW0RM

No progress yet. Haven’t taken mine in yet. But if you take yours in please keep me posted.

I actually did take it in and all that I heard back is no code all good bs from them. I'll pull my intake out and check the clips and rubber seal down there tonight to see if it's just a vacuum leak.

[BIGW0RM]

Originally Posted by yves998

I actually did take it in and all that I heard back is no code all good bs from them. I'll pull my intake out and check the clips and rubber seal down there tonight to see if it's just a vacuum leak.

It sounds like mine does. I have no intakes. But did on my G80 M3, so I know what those sound like. I dont think its that.

Next time you hear it. Pull your head forward towards your front window. When I do that, I dont hear the sound anymore. But when I lean back into my seat, I can hear it. So I know mine is certainly coming from the rear area. Hopefully its nothing for both of us. And maybe its just now they sound. I sure hope so.

Also, I noticed in your video that you where very close to 62MPH when I heard yours. One thing to try is, disable your exhaust button inside the car. Put it in automatic and efficent mode and let it get into 6/7/8th gear. I can hear mine much easier when Im in higher gears with exhaust fake sound off.

[aerobod]

Originally Posted by BIGW0RM

Also, I noticed in your video that you where very close to 62MPH when I heard yours.

That would be in km/h, so it is only showing from 31 to 39 mph (50 to 62km/h) in the video.

[yves998]

Originally Posted by BIGW0RM

It sounds like mine does. I have no intakes. But did on my G80 M3, so I know what those sound like. I dont think its that.

Next time you hear it. Pull your head forward towards your front window. When I do that, I dont hear the sound anymore. But when I lean back into my seat, I can hear it. So I know mine is certainly coming from the rear area. Hopefully its nothing for both of us. And maybe its just now they sound. I sure hope so.

Also, I noticed in your video that you where very close to 62MPH when I heard yours. One thing to try is, disable your exhaust button inside the car. Put it in automatic and efficent mode and let it get into 6/7/8th gear. I can hear mine much easier when Im in higher gears with exhaust fake sound off.

I actually even coded the ASD off to make sure it's not some fake intake noise and it isn't. I did tried cruise control on the whining speed and it turns out to be a consistent mild whining noise with cruise control on. I also tried to open the window buy a little bit and it turns out the noise is actually still there. Just hardly as noticeable as window closed.

[yves998]

Originally Posted by BIGW0RM

It sounds like mine does. I have no intakes. But did on my G80 M3, so I know what those sound like. I dont think its that.

Next time you hear it. Pull your head forward towards your front window. When I do that, I dont hear the sound anymore. But when I lean back into my seat, I can hear it. So I know mine is certainly coming from the rear area. Hopefully its nothing for both of us. And maybe its just now they sound. I sure hope so.

Also, I noticed in your video that you where very close to 62MPH when I heard yours. One thing to try is, disable your exhaust button inside the car. Put it in automatic and efficent mode and let it get into 6/7/8th gear. I can hear mine much easier when Im in higher gears with exhaust fake sound off.

I just switched my rear diff oil to royal purple 75w140 and the noise is getting quieter and quieter. I'll report back after two tanks of gasoline and see if it can cure it once for all. I can already confirm the noisy speed rangeb is only 65-70kph now after like 15min drive and the cruise control at 65kph noise is only like half as before. Hopefully I found the cure!!

[BIGW0RM]

Originally Posted by yves998

I just switched my rear diff oil to royal purple 75w140 and the noise is getting quieter and quieter. I'll report back after two tanks of gasoline and see if it can cure it once for all. I can already confirm the noisy speed rangeb is only 65-70kph now after like 15min drive and the cruise control at 65kph noise is only like half as before. Hopefully I found the cure!!

Interesting. Hopefully that solves it for you. Im going to take mine in someday sooner than later. Just dragging my feet on getting it in. Ive searched a lot of threads about this across all BMWs and it seems majority of them got a diff replacement. So Im expecting that is what they will do to fix mine. Not thrilled about it. But it is what it is.

Good luck on your solution!

[Dave07997S]

Originally Posted by BIGW0RM

Interesting. Hopefully that solves it for you. Im going to take mine in someday sooner than later. Just dragging my feet on getting it in. Ive searched a lot of threads about this across all BMWs and it seems majority of them got a diff replacement. So Im expecting that is what they will do to fix mine. Not thrilled about it. But it is what it is.

Good luck on your solution!

You know what you can try...get an extra bottle of friction modifier for the rear diffy. I remember with my E46 M3 back in the day when making sharp turns it would make some groaning. They added some more friction modifier and it solved it. I had a buddy used the Ford Racing friction modifier in his E92 M3 and it solved some noises coming from his car.




https://www.amazon.com/Ford-CM19546A...34289659&psc=1


Dave

[aerobod]

If the diff does have a problem and it is filled with the wrong oil (BMW specifies 75w80 GL-5/G4 oil for the G87 diff) together with additional friction modifier, they are highly likely to deny any warranty repair on it.