[bt49qt28c]

Hello dear friends, hope anyone can help me solve this thing. I've owned more than 30 BMW's, always went away from xdrive because I was witnessing people having many problems. Long story short I've got this 420xD F32 for cheaper price so I couldnt resist buying it... Immediately when I bought it it had strange clunk on takeoff and thumping sound above 100kmh. The clunk from the rear is solved with a brand new CV rear cv axle.

The noise however was still here so i suspected wheels and tires so I got brand new tyres all round in same size. Noise still there. Vibration is almost close to none, however as I speed up above 90kmh / 50 mph it starts and then becomes a little louder as I accelerate up. The sound comes from front low area, I cant define exactly if it is from the front suspension or below close to footwell area. Now the funny thing is immediately when I take off my foot from the throttle, it dissappears.. Then again the moment I step on the throttle again, it continues making the same noise. This goes up until 160 kmh / 100mph where it kinda gets quieter or maybe it's just the wind blowing and the doors not sealing well because its a coupe makes it seem like it does quiet down...

I hope I will be able to upload a recording of the noise so you can hear it although it is raining for 2 weeks here so I cant take a proper video that it can be heard very well. I suspected front cv axle driver side had some issue so I changed it. Noise is still there. I suspect now Front Differential or Front Drive Shaft.

Judging by the sound I think it is not the front differential, since I have heard that exact same differential make noise on my buddy's x5 f15 and it sounded like droning sound very similar to a failing wheel bearing high pitched, and it was starting from low speed like 50kmh/30mph and as you speed up it was getting very very loud and uncomfrotable that you cant drive the car... Mine is however different, it sounds deep and like rotational... So that is why I suspect the front driveshaft.

I am not very familiar with xDrive and the way it works but this is what I suspect.

The car makes the noise above 50mph. On the forum I have read about the theory that xdrive completely disengages sending power to the front differential as you speed up above 60mph. Does this mean the noise starts comming after the differential is "free" from power from the back.

The front driveshaft has 2 joints, one at the gearbox side and one at the front differential.

}--------------------{ <----- SOMETHING LIKE THIS

I know these 2 joints should move freely without any resistance. Now what I experienced with this car is that whenever I come to a slight hill it immediately drops a gear down even if it has high speed and enough rpm to climb the hill in 8th gear. This gives me further suspect that something is giving resistance so it is getting harder on the engine or the driveline and that's why it drops a gear immediately...


So for anyone who had a front driveshaft issue or a front differential issue, did you experience any of these symtoms and what should be the right way to inspect this thing, should I start by taking out the front driveshaft and try driving without it? If i remove it and disable DSC will I be able to test if the noise is there, will it do any damage to the transfer box? Any help is much appreciated..

Im one of the new members of the "I hate xDrive Community".

[bt49qt28c]

https://www.youtube.com/shorts/mufQyJKjhiY
This is kind of what it sounds like..