crewzer

Our ?new? 2006 E61 530 Xi has developed a drivetrain ?whine? over the past several weeks.

Noise description:

• A somewhat high-pitched mechanical ?whine? (tire whine, or gear whine), but not a squeal
• No apparent low-frequency component
• Directly related to road speed
• Perceptible starting at ~12 mph, peaks at ~37 mph, then inaudible at >40 mph
• Some, but not much, difference if the car is under load (accelerating), coasting in neutral, or decelerating in gear
• Slightly worse after car has fully warmed up
• Not at all related to engine speed or transmission gear selection
• Driver and passengers all agree whine is emanating "from the front"
• Somewhat less noticeable after pressure in all four tires equalized to 34 psi cold
• Whine not audible when car is on a lift (all four wheels raised) and wheels driven at indicated 0 ? 40 mph

Vehicle description:

• 2006 530xi Touring/Sports Wagon (E61) with xDrive AWD
• Just under 42K miles on the odometer
• N52B30 engine (a jewel!)
• Six-speed manual transmission
• All four tires match: Velozza ZXV 225/50R17 98W XL M+S, date code 1711 (Never heard of ?em? Me neither?)
• 93 AKI Shell gas
• 28.5 mpg (calculated) on the highway

Variable operation parameters:

• HDC on/off ? no effect
• DTC on/off ? no effect
• DSC on/off ? no effect
• No codes or warning lights

Recent maintenance (no effect on noise):

• Changed coolant (BMW + distilled water)
• Changed engine oil and filter (GC 0W-30 + Mann)
• Changed front diff fluid (Redline 75W-90; old looked OK)
• Changed MT fluid (Redline D6 ATF; old looked nasty)
• Replaced CDV with ?open? Zeckhausen model
• Changed rear diff fluid (Redline 75W-90; old looked OK)

I have new transfer case fluid, but I haven?t changed it yet. Access to the drain plug is relatively easy, but access to the fill plug requires dropping part of the exhaust. Car will probably go to BMW to reset the xfer case calibration after the fluid change.

So, any ideas about the source of the whine? We're thinking about mounting the tires and wheels on my son's E34 (offset permitting...) to see if the whine follows the tires...

Thanks!
Jim / crewzer

Theo

Based on the description (silent under no load, speed dependent) I would say some front suspension / drive component but that's probably obvious. One thing I wondered: does turning affect the whine at all?
I would do the following to find out about the exact cause:

- Don't you have an unmounted summer/winter set you can exchange with, would eliminate the tires/wheels as culprit and would allow for a better comparison than involving the E34.
- I would make a video and post it here and in the E60 section which is frequented by far more owners, including those with Xdrive.

Good luck!

crewzer

Theo,

Thank you for your response.

Turning corners does not affect the whine. Unfortunately, I don't have an alternate set of tires available.

My older son and I are going to try to change the transfer case fluid this weekend. After ~42K miles (~68K kms) and six years, it's probably due for a change anyway.

Thanks, and I'll keep you posted.
Jim / crewzer

phelix

Try running your hands over the tire treads looking for any unevenness or cupping...

Can you temporarily swap the front and back wheels to see if that changes anything?

crewzer

Phelix,

Thanks for the reminder... We thought about rotating the tires, and then forgot. The tires are asymmetric, so it'll have to be a same-side front-to-back swap.

The tires are not too old (mfr date 17th week of 2011, so ~end of April, 2011), and the wear appears to be OK. There's no vibration or pull in the steering.

I stood on the side of our quiet street as my wife drove away to work this morning, and the whine was not apparent.

Thanks,
Jim / crewzer

phelix

What does the tread patten look like? Can you post a photo?

crewzer

I'm not sure I'll be able to change the xfer case fluid this weekend, so I'm planning on at least rotating the tires. My new "wheel hanger" arrived in the mail today. I'll (try to remember to) post a tire tread pic this weekend.

Thanks!
Jim / crewzer

crewzer

Update:

My younger son helped me rotate the tires (front <> back, same side) yesterday, and we still have the whine.

All tires looked good. The attached pic is the original LR tire; the left side is the "outside".

Next step is to change the xfer case fluid later this month.

Regards,
Jim / crewzer

tongeman

Did you ever find the source of the whine my 2006 525xi 6 speed tranny does the exact same thing. Your discription cannto be said any better and is decribed as exact of mine.