[HiredGun]

Now that my differential whine problem seems to be resolved, I thought I would create a thread that summarizes the issue in case there is anyone else with a similar problem. In short, my brand new 2011 328i (August 2011 build date) exhibited a classic differential whine as is characterized in technical discussions/write ups. (Google “differential whine” or “differential preload whine”)

Having had the car for only a few weeks, I was naturally concerned. My concern was significantly raised when I was put into a 2010 328 loaner that had the exact same problem. Although the loaner was not quite as loud as my 2011, it was definitely the same issue. I took away from my discussions with my dealer’s service department that this is a well-known problem and that BMW differentials are prone to make noise. The dealer has been very forthcoming with me about the issue and I should note that my experience with the dealer and BMW regarding this problem has been very positive thus far. The service department’s shop foreman immediately heard the noise during the first test drive. We agreed that is sounded as though the sound was in the rear end. After some time and some interfacing with BMW, my SA advised me that they were replacing the differential. She stated that my rear end whine was about twice as loud as other cars that had the noise.

I picked up my vehicle this morning and drove it to work. There was no noise coming from the rear end; the noise is definitely gone.

My understanding with a differential is that they will make noise if they are not setup correctly. I had also read that “machining variations” of the ring and pinion gear set can also result in a whine. As an engineer with no experience with setting up or building a diff, all I can say is that this sort of makes sense when the gears are not properly aligned or a bearing is loaded improperly. Perhaps an expert could comment on this or elaborate on the types of noises a differential should or should not make.

Although this issue seems to be resolved for me, something still concerns me about the problem based on my very limited understanding here and based on my discussions with the service manager and the service advisor. They both implied and even stated that this is a common problem, but since mine was louder than normal (“twice as loud”), they agreed to fix it. It seems to me, however, that the whine noise that I had was in no way normal or good.
Perhaps there are others here that could share their experience, assuming of course that my car and the loaner car are not the only vehicles with this issue. I have made several good audio recordings of my car before the fix and of the loaner from inside of the cabin. If there is interest, I could produce a compilation video of the recordings. Using a very simple filter on the recording, the differential whine can be isolated. It has a very definitive pitch.

[dtc100]

Was it very obvious your whine came from the rear? If I am not mistaken a few complaints about whine coming from the engine bay not from the rear.

[07E92TT]

my loaner has 2k miles on it and it whines a lot. Sounds like a turbo spooling up or something lol but its a 328

[HiredGun]

You cannot tell where it comes from; at least I couldn't. At first, I was convinced it was the engine. One thing I did is have my son drive and I sat in the back and pushed my ear against the sides of the hump on the floor between the seats while he put the car at a speed that produced the noise. Even then it was difficult to discern where it was coming from.

[HiredGun]

Originally Posted by 07E92TT

my loaner has 2k miles on it and it whines a lot. Sounds like a turbo spooling up or something lol but its a 328

Yep, that what I though too.

[osukf09]

I've had this whine for a few months and finally took it in to the dealer. After having it for just the morning the SA already called and told me the tech was already ordering a new diff for my car. That was easy. Car is a 07 e90 335i CPO so hopefully this will be the end-all for the whine issues (minus a few turbo spools here and there!)

I had never figured it to be the diff or anywhere near the rear end. I was sure it was something in or around the front of the car, possibly transmission related because the pitch of the whine changed in relation to the car's speed, not the RPM's. The sound almost reminded me of a siren (without the pulsating up and down noise, just the high pitch) mixed with the sound of a car with a open filter air intake.

[JohnSprm69]

Originally Posted by HiredGun

(August 2011 build date)

[HiredGun]

Good luck apj. Unfortunately for me, the new (remanufactured) differential has developed the same noise as the original. I have created a short video that demonstrates the sound using a recording from a sony digital recorder.

The video shows in the spectrum analysis that there is a high volume sound at approximately 1400Hz. If you have a tool like Audacity, try generating a 1400Hz tone and play it back....I cannot imagine spending 50,000 or 100,000 miles with this car the way that it is. BMW refuses to do anything about it. There is a shop foreman at a local dealer that said they have tried to fix this issue in the past and that they are no longer replacing differentials to address it. Apparently, the sound comes right back after about 1000 miles, which is exactly what mine did.

So, according to BMW, this is a normal sound for the industry's benchmark sports sedan. Unbelievable to me.

(Oh, and I should also note, that it is very difficult to discern that the sound comes from the rear end. I thought it was in front of me too.)

[Dackelone]

Normally the rear diff noise is caused by improper break in. ie: full throttle starts and exceeding the 100 mph sped limit durring the (1,200 mile)break in time period.

I have driven a few rental BMW from SIXT that had this slight rear diff whine. The whine is only under cruising condition... under light throttle. When you give it full or 3/4 gas pedal the noise goes away. Classic rear diff noise.

I would also think it wise to change the rear diff fluid out. Perhaps this is one of BMW calculating risks they take with the zero maint OCI plan.

Dackel

[HiredGun]

Thanks for the post Dackelone. The whine is most persistent under light to moderate throttle, just as you noted. It does get louder at specific speeds and is obvious under reverse loads (slowing down). Unfortunately, my drive to work everyday is at speeds between 45 and 50 mph which is when the sound is at its loudest.

[John 070]

I played back that clip of the whine, and my dog immediately stood up and came over! Perhaps BMW should deploy labrador retrievers at the assembly line to remove the whiney differentials at the factory.

That sound is annoying--sheesh, I hope I don't develop it. I don't want some remanufactured part going back into my car. Remanufactured is cheap--like body work. There is an incentive to not do it well. How many of us have installed remanuf starters, alternators, brake calipers, etc. Ask yourself--did they last as long as the original? With people not keeping things a long time anymore in general, remanufacturers get away with shoddy replacement parts imho....

[HiredGun]

Originally Posted by John 070

I played back that clip of the whine, and my dog immediately stood up and came over! Perhaps BMW should deploy labrador retrievers at the assembly line to remove the whiney differentials at the factory.

Great idea. They have dogs that are trained to sniff drugs, find people, find illnesses. We could train them to identify hard to find problems. Also, some of the dealers (not necessarily BMW) I have dealt with in the past could hire a K-9 or two and significantly bring up the IQ of their service departments....

[John 070]

Originally Posted by HiredGun

Also, some of the dealers (not necessarily BMW) I have dealt with in the past could hire a K-9 or two and significantly bring up the IQ of their service departments....

Totally agree, like when I was told, "I don't know what it is you'd like us to do."

Hmmm.....335i, car stalled 3X on the expressway, maybe fix it?

What drives me crazy with BMW is the lack of wanting to do a good job. They're not going to get me to buy a new car again, BMW is been there, done that. Either I'll get a Porsche (if my career allows) or probably an Infiniti (not as good performance but I can live with having a car problem-free for a decade). I'll keep my 335i forever, just wont buy another new one. The value has already sunk to a point where I wouldn't want/need the trade-in--23.8 and it's going on 51 mos. old. 23,800....LOL

[HiredGun]

Originally Posted by John 070

The value has already sunk to a point where I wouldn't want/need the trade-in--23.8 and it's going on 51 mos. old. 23,800....LOL

I try not to think about such things.

Originally Posted by Dackel

I would also think it wise to change the rear diff fluid out. Perhaps this is one of BMW calculating risks they take with the zero maint OCI plan

This might be something to suggest to my dealer, however two of my local dealers are saying that the car is "operating per BMW specs and design". By suggesting this is a calculated risk, are you saying that this would be an indicator that the differential could wear sooner? My understanding is that whines can be caused by poor setup, wear, bad gears, etc.

[CombatNinja]

FWIW, just picked up a 2009 CPO e91 for the wife. Car was a service loaner and never titled with factory warranty until October 2013 and CPO cover until October 2015. Her car is making this noise very faintly (she hears it more than I, probably down to a woman's naturally better hearing and my exposure to excessive gunfire and explosions) under light throttle. Is BMW refusing to replace any more diffs for this noise across the board or is this a case-by-case thing? I may change the fluid once to see if that cures it but I can forsee them denying a future claim once they see that the fluid was changed outside the dealer network.

[HiredGun]

Originally Posted by CombatNinja

Is BMW refusing to replace any more diffs for this noise across the board or is this a case-by-case thing? I may change the fluid once to see if that cures it but I can forsee them denying a future claim once they see that the fluid was changed outside the dealer network.

BMW changed my differential in December, and it was a tech from another dealer that stated they are not changing differentials anymore. These two things are somewhat contradictory, so I'm not sure what the official policy is. My guess it is case by case, but BMW (probably my region's representative) has stated they will not do anything more for me.

If you raise enough ruckus, you might be able to get the dealer to replace the fluid for you. Just be careful of going down the path replacing the differential; the whine may come back. Also, note that BMW only lists a Remanufactured part for the diff. In all likelihood, you'll end up with a remanufactured part if you have it replaced.

Also, I heard the sound in the service loaner that I was given while the differential was being replaced. It was not quite as loud, but definitely the same noise. My fear was that the problem would not be resolved, which is exactly what is happening.

[John 070]

Originally Posted by HiredGun

I try not to think about such things.

The resale value is only of concern if you need to get rid of the car, if not, the resale could be 10k, and it feels funny, but it's of no consequence. If someone approached me on the street and said, "Hey, pal, I have 24,000 cash in a bag, and will give it to you for your 2007 335 E92 ZSP ZPP 6-man, 25k miles with 7/100 factory extended warranty, that is $200 more than what it's worth you know." I'd tell him no thanks....that's a paper number that only affects people who are trading their cars or selling them....

[hwboi]

Originally Posted by HiredGun

Good luck apj. Unfortunately for me, the new (remanufactured) differential has developed the same noise as the original. I have created a short video that demonstrates the sound using a recording from a sony digital recorder.

The video shows in the spectrum analysis that there is a high volume sound at approximately 1400Hz. If you have a tool like Audacity, try generating a 1400Hz tone and play it back....I cannot imagine spending 50,000 or 100,000 miles with this car the way that it is. BMW refuses to do anything about it. There is a shop foreman at a local dealer that said they have tried to fix this issue in the past and that they are no longer replacing differentials to address it. Apparently, the sound comes right back after about 1000 miles, which is exactly what mine did.

So, according to BMW, this is a normal sound for the industry's benchmark sports sedan. Unbelievable to me.

(Oh, and I should also note, that it is very difficult to discern that the sound comes from the rear end. I thought it was in front of me too.)

Hi guys, I'm new to the forum and just purchased a used 2009 328i with 20k miles on it. Everything is great so far but I am hearing the exact same noise as recorded here. Is this something to be concerned about or am I just stuck with it because the car wasn't properly broken in? I've done some searching but haven't found a definitive answer. Some say replacing the fluid helps and others have managed to get BMW to replace the rear diff...but only to have the noise eventually come back.

Thanks in advance for any responses!

[roger911]

I just had a loaner 4-door 328i (2011) for two days, and I heard it too!! The car only had 400 miles on it. It reminded me of my mom's Dodge Shadow. I was shocked. That would have driven me crazy!

[ABerry]

Originally Posted by 07E92TT

my loaner has 2k miles on it and it whines a lot. Sounds like a turbo spooling up or something lol but its a 328

yup my '11 328xi loaner has the whine and the n52 tick at 9k miles.. I've never heard the whine in my car tho.. I wonder if this is a break-in issue? I definitely pushed the n52 to some limits to get some comparison

also what is the recommended year and mileage to replace the diff fluid, i don't want to RTFM when I have this online resource

[kvanriper]

I have a july 11 build date and it whine started a few months ago. Very loud. Now that tax season is over I'm going to take it in. It starts around 40 mph loudest at 53 - 55 mph

[HiredGun]

My whine is worse than ever. Good luck to anyone trying to have this resolved by BMW. It's "a pimple on an elephant's butt" according to the ever so tactful BMW attorney that I have had to deal with.

Oh, and by the way, the attorney for BMW found my postings on this forum and attempted to use them against me in the lemon law hearings. He took statements I've said here and brought them out of context into my hearing. Be careful with what you post, BMW is watching......