Harsh noise when accelerating at low RPMs

[Duke I]

When I determined how to replicate the noise I just focused on mph and moving to 6th gear at 35-45 mph. I drove tonight to note the rpm and the sound occurred right at 1500rpm. As it turns out, I was able to repeat the sound in manual in all gears 2-8 at that 1500rpm. To be clear, the sound occur with normal rpm/mph mapping in auto mode but the car does not linger at 1500rpm for long. In fact, 1500rpm is just about the shift rpm point in comfort mode.

Could it be the serpentine belt on a misaligned pulley? Still stumped.

D

[DuSh]

Originally Posted by Duke I

When I determine how to replicate the noise I just focused on mph and moving to 6th gear at 35-45 mph. I drove tonight to note the rpm and the sound occurred right at 1500rpm. As it turns out, I was able to repeat the sound in manual in all gears 2-8 at that 1500rpm.

Could it be the serpentine belt on a misaligned pulley? Still stumped.

D

Can you make a short video with sound so we can hear it. Where do you feel noise is coming from? If its in all gears at 1500rpm - it's not a belt or pulley - belt/pulley noise would not disappear suddenly, it will just change frequency (become faster/slower). Maybe it's just resonators trembling at around 1500rpm and touching heat shields lol?
Also, does sound disappear right after 1500rpm or it continues to let's say up to 2000rpm?
If you can find a empty clear road and reproduce sound and then put it in neutral and coast a bit - will sound go away (rule out engine) or stay (engine related)?
Do you have a code reader?

P.S. I know I said it before, but can you raise the car on hoist at any local shop and pull the plug from TC (5 min job)? It will light an error light on dashboard, but you'll rule out TC - and i think it sounds a lot like TC imho.

[Duke I]

Thanks DuSh

Sound starts at 1500 and disappears as rpm goes beyon that level. I can maintain the sound by having rpm linger at 1500 but only under load and not coasting. Sound seems to be from the lower front of the passenger footwell. I'll see if I can capture the sound in a recording.

I do not have a code reader and I assume the dealership looked for codes when my car was in during the 3 week period.

I'll try to do the TC test this weekend. I looked for the plug last night but quickly determined that I'll need to jack the car up to get to it.

D

[Gtz1wickedest]

Originally Posted by Duke I

Thanks DuSh

Sound starts at 1500 and disappears as rpm goes beyon that level. I can maintain the sound by having rpm linger at 1500 but only under load and not coasting. Sound seems to be from the lower front of the passenger footwell. I'll see if I can capture the sound in a recording.

I do not have a code reader and I assume the dealership looked for codes when my car was in during the 3 week period.

I'll try to do the TC test this weekend. I looked for the plug last night but quickly determined that I'll need to jack the car up to get to it.

D

When my transfer case went completely this is the identical noise I was getting

[DuSh]

Originally Posted by Duke I

Thanks DuSh

Sound starts at 1500 and disappears as rpm goes beyon that level. I can maintain the sound by having rpm linger at 1500 but only under load and not coasting. Sound seems to be from the lower front of the passenger footwell. I'll see if I can capture the sound in a recording.

I do not have a code reader and I assume the dealership looked for codes when my car was in during the 3 week period.

I'll try to do the TC test this weekend. I looked for the plug last night but quickly determined that I'll need to jack the car up to get to it.

D

Yeah, so passenger footwell is about where TC is underneath. If you don't have code reader, I'm not sure if errors will go away after you'll plug it back or they will stay. I'm planning to unplug TC too (to do burnouts and donuts lol as car will be RWD essentially), but I have code reader and i can clear error codes afterwards if they will still stay after plugging it back. So I don't want to put you into situation that you will have error lights on dash.

It's visible when you look at it underneath but a bit hard to reach if car is not on hoist. It's a black plug - the only one on the TC.

Here's my old post with a bit of photos to better show where that plug is: https://f15.bimmerpost.com/forums/sh...74&postcount=9

[Duke I]

Originally Posted by DuSh

Yeah, so passenger footwell is about where TC is underneath. If you don't have code reader, I'm not sure if errors will go away after you'll plug it back or they will stay. I'm planning to unplug TC too (to do burnouts and donuts lol as car will be RWD essentially), but I have code reader and i can clear error codes afterwards if they will still stay after plugging it back. So I don't want to put you into situation that you will have error lights on dash.

It's visible when you look at it underneath but a bit hard to reach if car is not on hoist. It's a black plug - the only one on the TC.

Here's my old post with a bit of photos to better show where that plug is: https://f15.bimmerpost.com/forums/sh...74&postcount=9

Talked with the dealer today about the rpm findings and asked them if they'd checked the TC case for the noise. They asked me to bring the car in next week and they'll unplug the TC and then we'll do a test drive together.

[Tarsier]

Any luck resolving this? I have had the same issue for the past year with my 2015 50i with DHP.

[HydroStream6]

I think I have a similar noise too on my 50i. Although to me it just sounds like a harmonic in the cabin at high load low rpm. If it's the same noise I have, I'm not worried about it.

[X5M(s)F15]

I have a 2015 X5 that makes a weird sound when accelerating on 1st or 2nd gear at low rpm (1800/2500). Is this normal? Doesn't seem like it should be but my BMW SA is saying this is normal. I took it in for a third time to try to resolve. They've replaced my belt tensioner and my turbo but no change. I have 500mi left on my 50k mi warranty and what to make sure it doesn't become and issue later...any thoughts...

Sound Clip: mic in the engine bay.

https://drive.google.com/file/d/1EfM...w?usp=drivesdk



Thanks
Duran

https://f15.bimmerpost.com/forums/sh....php?t=1594323

[HJ]

Originally Posted by X5M(s)F15

I have a 2015 X5 that makes a weird sound when accelerating on 1st or 2nd gear at low rpm (1800/2500). Is this normal? Doesn't seem like it should be but my BMW SA is saying this is normal. I took it in for a third time to try to resolve. They've replaced my belt tensioner and my turbo but no change. I have 500mi left on my 50k mi warranty and what to make sure it doesn't become and issue later...any thoughts...

Sound Clip: mic in the engine bay.

https://drive.google.com/file/d/1EfM...w?usp=drivesdk



Thanks
Duran

https://f15.bimmerpost.com/forums/sh....php?t=1594323

If the dealer found nothing wrong could be something minor like tires. Do you have runflats? Mine wasnt as loud as yours but I get the similiar howling noise on my 19s with runflats but on my 20s without runflats the noise goes away.

[X5M(s)F15]

Originally Posted by JSN

If the dealer found nothing wrong could be something minor like tires. Do you have runflats? Mine wasnt as loud as yours but I get the similiar howling noise on my 19s with runflats but on my 20s without runflats the noise goes away.

it's definitely coming from the engine bay. (I also have 20s w/o runflats). I just can't figure out where it's coming from and the DLR can't either. if it's normal,they should be able to tell me what's making the noise.

[Duke I]

Mine is not resolved yet. Still awaiting the tech guy to show up. My sound is more of a chirp than what x5m recorded and not the pronounced knocking in the gtz video. Seems to be getting worse. D

[ThatKasper]

Originally Posted by Gtz1wickedest

When my transfer case went completely this is the identical noise I was getting

That LOUD AF banging when you crank your steering wheel all the way left or right??? I thought we were talking about a whining/whirring sound coming from the engine...this video is NOT that!

[Gtz1wickedest]

Originally Posted by ThatKasper

That LOUD AF banging when you crank your steering wheel all the way left or right??? I thought we were talking about a whining/whirring sound coming from the engine...this video is NOT that!

He's just turning but the noise happened when you accelerated doesn't matter turning or not.. dealer covered it under warranty work order said transfer case.

[Bomzara]

Hello guys, just faced the same issue on my 2014 X5 when going uphill (or under slight load). It only happens on operating temperature (never heard it on cold engine) and only within certain RPM range (approx 1700-2500 RPM). I can barely hear it with side windows closed, but once I open them - the rattling/knocking noise is definitely noticeable.

Has anybody managed to fix it?

[ioannisST]

Originally Posted by Bomzara

Hello guys, just faced the same issue on my 2014 X5 when going uphill (or under slight load). It only happens on operating temperature (never heard it on cold engine) and only within certain RPM range (approx 1700-2500 RPM). I can barely hear it with side windows closed, but once I open them - the rattling/knocking noise is definitely noticeable.

Has anybody managed to fix it?

Yes!! The gearbox that using BMW is made from ZF. Unfortunately
ZF has issues with electrovalves. Non mechanics call the electrovalves = solenoids. By factory these solenoids fail. Why ? Because ZF have factories around the asiatic area where their work efficiency is low.
You need to contact ZF and get new solenoids. Don’t ask your self, if there was an issue with solenoids would have been shown to diagnostic tools. No chance to test solenoids without touching them.
After this everything will be back to normal. No more hesitation on incline, 1-2-3 gear, when you come to full stop and no this rattling noise.
Have a beautiful day

[Fknid]

Originally Posted by ioannisST

Yes!! The gearbox that using BMW is made from ZF. Unfortunately
ZF has issues with electrovalves. Non mechanics call the electrovalves = solenoids. By factory these solenoids fail. Why ? Because ZF have factories around the asiatic area where their work efficiency is low.
You need to contact ZF and get new solenoids. Don’t ask your self, if there was an issue with solenoids would have been shown to diagnostic tools. No chance to test solenoids without touching them.
After this everything will be back to normal. No more hesitation on incline, 1-2-3 gear, when you come to full stop and no this rattling noise.
Have a beautiful day

I doubt this very much.