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If the steering wheel is pointed straight there is no noise. If I move the wheel a small amount off center I can hear a vibration rattle from the front of the car/engine compartment. Move the wheel back to center and the sound stops. This is also coupled with the orange and then red dynamic drive warnings coming on almost every day. I know the most common dynamic drive issue is voltage but with the underhood noise I think I've got something real happening. I am working on getting DIS but don't know how this will help me troubleshoot or if there is anything else I can do. PS fluid is at the 20C max level when it's 20C outside.
 

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Hello guys,

I'm running into the same problem on my E65 740d.
It's totally driving me nuts as I pretty sure that something is related to the Dynamic Drive.
The other day, my battery was quite dead and obviously, a lot of systems weren't activated, particularly Dynamic Drive (with the infamous error on the middle screen/MMI/MMIGT).
At that time, no more vibrations were occuring, and just to re-emphasis the problem, it's the same as rojeho described :
  • A low speed (<10 km/h) no vibration
  • As soon as 10/15 km/h are reached, vibration occurs
  • Vibration tends to occur while steering something like 20° with the steering wheel to the right OR to the left (same vibration for both sides)
  • Vibration seems to be linked to engine RPM (but not 100% sure)
  • When the vibration occurs while steering, getting the steering wheel to the center immediately stops it
Some things to keep in mind :
  • I'm pretty sure that the Dynamic-Drive/steering assistance fluid reservoir has never been changed
  • There was a leak on the Dynamic-Drive/steering assistance intercooler connectors (located close to the left headlight) >>> Changed the o-rings, but still leaked > replaced the intercooler : no more leak
  • Only some hundread kilometers after replacing the intercooler with no more leak, problem appeared while driving on the highway on something around 200km
  • Since then, vibration is stable, it is not getting worse over time (or quite not // or so low that I can't even notice it getting worse 😅 )
My car has 334000Km mileage and I'm pretty sure I might have to replace some things like :
  • Dynamic-Drive/Steering assistance fluid reservoir (as the Dynamic-Drive equiped models are bigger and contains a filter ... might be clogged after all these kilometers)
  • Maybe (just maybe) a wheel bearing getting bad // I might admit that I can feel the vibration on my left foot on my european model (steering wheel to the left)
  • Maybe, my "tandem-pump" is getting bad, but I'm sure this is only a matter of o-rings to be replaced ... which BMW doesn't sell as a "gasket replacement kit" ... of course tsssss 😒
  • I've learned from this video that sometimes this problem can be linked to a high pressure hose that gets bad over-time
Anyway, if someone has some advice to give me : you're welcome to do so pleeeeeeeaaaaaaaaaaaaase 😅
 

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You can rule out the bearing by lifting the suspected wheel into the air a bit, so it is free. then try moving the tire back and forth. it should have no play. also spin the tire, a bad bearing can also making grinding noises, which you may hear while spinning the tire.

if you are thinking your p/s fluid is all gunked up, a quick way to MAYBE find out, is to suck some out of the reservoir and examine it.
 

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I think I already did this, but just in doubt (and because I'm running out of solutions 😅 ) I'll definitely give it a new try ... just to be 100% sure that it's not as simple as a wheel bearing.

Anyway, could a wheel bearing be generating vibrations only when applying lateral forces on it and nothing in a straight line ?
That seems strange to me but as this kind of bearings are usually double tapered roller bearings, that would maybe make sense that it can vibrate only when received axial/lateral forces.
 

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If you opened up the lines to the Dynamic Drive system, you probably should recalibrate the DD. This can be done with DIS or ISTA. If you are having low voltage issues, this will tend to isolate the functions of the DD. It is really rare that the DD actually fails, I would suspect something like one of the control arms might be bad? Inspect the rubber bushings for cracks in the rubber, as this will cause vibration at certain speeds. A bad wheel hub bearing will usually tend to grind some thru either a right or left hand turn, based on which side the bad bearing is on. You will feel this thru the steering wheel while loading the bearing on a slow loaded turn. IF you are getting the DD warning on the IDrive, this is usually related to a bad voltage regulator on the alternator. An aftermarket rebuilt alternator will usually be responsible for this warning. If the VR is going bad, it can be replaced by itself on the alternator. Not a dealer item, but can be found on EBay, the Valeo brand.
 

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Ok so this is something I didn't know : the fact that Once Dynamic Drive gets its lines opened, the system needs a (re)calibration.
How should it be performed ? using the Dynamic Drive test where the car moves by itself while engine is running ? (I have ISTA, INPA running on a laptop with an ICOM controller)

Regarding the wheel bearing, the vibrations occur the same while steering to the left or to the right ... so except if the bearing is absolutely/totally dead, I can understand that there is just a little bit of chance that the problem comes from this unfortunately :confused: ... Logical ... why would it be so easy ... BMW ... GRRRRRrrrrrr

Anyway, thanks for your answers guys, these are really appreciated !
I will report back once I've tried some possibilities reported here.
 

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Once the lines have been broken on the Dynamic Drive system, it should be initialized thru the test where the car will bounce around.

It would be odd for a bearing to fail very fast, unless it has taken a major impact.
 

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Hello everyone,
Still had no time to check all this, but tomorrow if I feel the energy of a lion, I will put myself under the car to check the arms bushings, but pretty sure they are 100% fine as they have been replaced recently.
Of course, except if the tech guy didn’t tighten them at suspension level, they might have suffered from cracks.

I wanted to point something more :
  • I have absolutely no warning/error showing up from Dynamic Drive
  • When driving over some bumps, I can hear some play in the front suspension, maybe an active sway bar is going bad
  • But … saying that, what I can feel in terms of vibrations is definitely linked to the engine RPM
That said, the front active sway bar is leaking a veeeeery little bit, but nothing really important to declare here.
Not sure if when these are failing, they absolutely need to spit out a lot of hydraulic fluid … or not ?!

I’m more and more feeling that this will end with a tandem pump going bad…

anyway, if some ideas come to your minds, please, feel free to tell me.
 

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Very rare for the DD to fail. The leaking on the sway bar is most likely from the drivers side of the sway bar, due to the boot on that side leaking. You can slide that boot back, clean it the metal & the inside of the boot very good, then apply some grey RTV on the metal, then slide the boot back in place. Give the RTV time to cure, then the leak should be gone. Mine has stayed this way for over 8 years now. If you really suspect something is wrong with the DD, I would change the reservoir, & drain all of the fluid out. The reservoir has an internal filter inside of it, & the new fluid could help to resolve the problem. If you have ISTA, you can test all of the DD components to see if any problems can be found. If the fluid smells burnt, one of the internal check valves could be failing, causing the system to overheat. Hopefully you will find a loose joint in the suspension, & all of the problems will go away.
 

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I have the same problem with my f11 530xd. I changed: DD pump, DD valve block, the rear shock absorber, the rear compresor and front active sway bar. Still can hear the howl/hum when steering right or left. To be sure that is DD problem just remove the fuse nr 45. Then no more bad sound…. Now are left only front shock absorbers, but I am think that is no cause of this f*****g sound. (Sorry for my English)
 

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If there is active steering on the car, it is possible that the active steering on the steering rack has cracked, & get.ting under a bind when turning the wheel either way. My housing in the middle part where it bolts to the steering rack, cracked on one side, then cracked on both sides. With the wheel not being turned in either direction, a loud whining noise starts. It sounds very odd, & mostly the sound comes from the center of the car. Once I replaced the middle (AS housing), all of the sound went away. This did not cause a DD warning at all.

If the one check valve on the steering pump has failed, this will cause a lot of cavitation in the oil system, & the steering pump will get louder as it gets more air in it. The fluid at that points becomes hotter, & will boil out of the reservoir.

If the DD actually fails, you will never feel or hear this on the car. The handling might change some, but you probably would not even notice the difference. The wheel bearings can be felt in the steering wheel at low speed turns, when the bearing is loaded in the direction you turn, you will feel a very small grinding feel.

When the struts fail, you will hear some noise when turning the wheel. They usually start to fail in the 80k range, or higher mileage. The struts can be rebuilt, much cheaper than replacing the complete strut. The car will set higher after replacing the struts, until they settle some.

If there is noise while turning the wheel, start checking out the pump, reservoir, & steering rack for problems. You will need to drop the plate under the engine to try & get a peek at the active steering housing. You don't say which year model you have, so it is hard to determine if the AS housing comes into play. The 2004 to 2005 models have a different steering rack, then the 2006 & up. Has any work been done on the car that could be related to this problem?
 

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On my side, problem is still present, I have bought a tandem pump which has 138000km.
I’m planning on replacing the pump + the reservoir.
After that I will initiate a Dynamic Drive calibration and see what happens.

pretty sure on my E65 I don’t have active steering on the steering rack as this model wasn’t equipped with it.
 

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Yes sorry about the fact that I have a 7/E65 series and this is a 6 series subforum but I couldn't find anyone having the same problem there and 6 series are quite equiped with the same components/system.

I made sure when ordering the tandem pump I bought that it was having the same references so it should be fine.

Anyway, I really hope and cross my fingers for the problem's root cause to be this damn pump ! 😅
 

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If the steering wheel is pointed straight there is no noise. If I move the wheel a small amount off center I can hear a vibration rattle from the front of the car/engine compartment. Move the wheel back to center and the sound stops. This is also coupled with the orange and then red dynamic drive warnings coming on almost every day. I know the most common dynamic drive issue is voltage but with the underhood noise I think I've got something real happening. I am working on getting DIS but don't know how this will help me troubleshoot or if there is anything else I can do. PS fluid is at the 20C max level when it's 20C outside.
What car is it?
 
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