[DrewWphoto]

Hey guys,

My 2007 328xi with automatic transmission and 66k miles on the odometer that just started making a whining noise three days ago (Tuesday) when I accelerate and decelerate. I can hear it from about 15 to 45 mph then I'm guessing it just goes too fast for me too hear it. It's a whining noise like what you might hear if your power steering pump was going out but it's matched with road speed not RPMs. And it doesn't happen when the car is stopped only when you start rolling.

To add, I was backed into at about 10-15 mph on Monday while I was stopped in traffic. The person hit the front license plate. Would that have anything to do with this since it started after that?

I only drive about 5 miles a day and will be driving my Mini until I figure out what's going on.

Please let me know your thoughts.

Edit to add (6/6/2016): here is what it sounds like from inside the car.

[DrewWphoto]

Man this is the first forum I've been on that has so little interaction. Are BMW guys just less knowledgable about this stuff?

[tonyjcchen]

sounds like wheel bearings to me. they whine when they start to go bad.

[DrewWphoto]

Would I be able to hhear that if I jack up the front end and spin the wheels?

[MR.BLUECOLLARMAN]

Originally Posted by tonyjcchen

sounds like wheel bearings to me. they whine when they start to go bad.

66k miles and bearings go bad? Dang, I don't know a lot about the 328s but I'm having a hard time thinking they would go out that fast. OP have you gotten your car scanned yet? Any faults or codes?

[NiNeTyOne]

Originally Posted by MR.BLUECOLLARMAN

66k miles and bearings go bad? Dang, I don't know a lot about the 328s but I'm having a hard time thinking they would go out that fast. OP have you gotten your car scanned yet? Any faults or codes?

Depending on a host of factors the bearings very well could be bad. Alignment plays a major factor in a wheel bearings life, as does rough road conditions, salt and other environmental factors.

Things for the OP to check include BOTH differentials (their fluid), potentially low transmission fluid, and all the wheel bearings. I'd also check the idler pulley and the belt tensioner, they can both make whining sounds that are tied to engine rpm.

[PhaseP]

Originally Posted by DrewWphoto

Man this is the first forum I've been on that has so little interaction. Are BMW guys just less knowledgable about this stuff?

It is because of two reasons. Not many people look at the xi section. Also, it could be a number of many things so not easy to answer.

You say it doesn't go with engine rpm but with road speed. So with this you mean if you change gears while moving the sound doesn't change before and after gear change?

If so obviously you can rule out engine related causes.

Then drive trains remains. There are bearings at the front differential, rear differential, a bearing at the center of the rear drive shaft, the four wheel bearings, and then a bearing on the front passenger axle "pedestal", where the front passenger axle goes into the oil pan (into a tube that opens up to front differential on other side of the oil pan).
And then there is the transfer case that has bearings and gears. There is also the transmission. Any one of these could be.

You mentioned it is either at acceleration or deceleration that is making the whine. I would think that would point more direct power delivery sections, i.e. less wheel bearing more transmission, transfer case, driver shaft. Maybe just 2 cents, not an expert.

There is also possibility it is your tires or one of the tires that started to wear unevenly.

Also something with brakes/rotor, sticking maybe?

You asked if you can find if it is a wheel bearing or not by lifting and turning it. I think you could, it is worth trying. You could check if it has any play, if it is turning smoothly or not. This would also rule out if brakes are the cause.

[DrewWphoto]

Originally Posted by MR.BLUECOLLARMAN

66k miles and bearings go bad? Dang, I don't know a lot about the 328s but I'm having a hard time thinking they would go out that fast. OP have you gotten your car scanned yet? Any faults or codes?

No fault codes. It's only been driven about 8 miles since it started making the sound, now it's just sitting in my driveway. Doesn't seem like the type of thing that would throw a code though.

I'm going to jack it up later this week and see what the front and rear differential look like and make sure there aren't any leaks. I guess I could just change out the fluid while I'm there.

The transfer case seems like it's a bit more of a pain to check and refill with oil but I'd rather just start with those 3 to be sure they're not what's causing the noise.

I don't feel like it's the wheel bearings since it doesn't seem to increase or decrease when I turn. It's much more dependent on speed. Feathering the gas doesn't seem to change the intensity of the sound from a shift in load.

This guy posted a video of the whine his 335xi trans was making and it sounds like the same noise but there is no advice or follow up on his thread. http://www.e90post.com/forums/showthread.php?t=1217675

Anyway, I'll keep you guys posted. Hoping it's not something major so I don't have to trade it in (kinda defeats the purpose of buying a lower mileage car)

[NiNeTyOne]

Originally Posted by DrewWphoto

No fault codes. It's only been driven about 8 miles since it started making the sound, now it's just sitting in my driveway. Doesn't seem like the type of thing that would throw a code though.

I'm going to jack it up later this week and see what the front and rear differential look like and make sure there aren't any leaks. I guess I could just change out the fluid while I'm there.

The transfer case seems like it's a bit more of a pain to check and refill with oil but I'd rather just start with those 3 to be sure they're not what's causing the noise.

I don't feel like it's the wheel bearings since it doesn't seem to increase or decrease when I turn. It's much more dependent on speed. Feathering the gas doesn't seem to change the intensity of the sound from a shift in load.

This guy posted a video of the whine his 335xi trans was making and it sounds like the same noise but there is no advice or follow up on his thread. http://www.e90post.com/forums/showthread.php?t=1217675

Anyway, I'll keep you guys posted. Hoping it's not something major so I don't have to trade it in (kinda defeats the purpose of buying a lower mileage car)

Front one is easy enough, but the rear one you need a siphon pump to drain. I'll be curious to know how much fluid comes out. Mine were a little low at a recent change, but there was no external sign of any leaking. In fact the under side of my car looks like it let the factory last month. I have not seen a diff "eat" fluid like that before so I'm just curious of the last tech who touched them under filled them. It wasn't much, 0.3L or so, but it was curious.

I used LiquiMoly 75w140 synth in mine and they are a bit quieter.

[DrewWphoto]

You could hear your diff before you put more fluid in? Is that why you checked in the first place.

[DrewWphoto]

So I was just reading up on some information and it was said that if while driving you step on the gas, let off the gas and step on the gas and hear the whine while on the gas then its the differential otherwise it's probably the wheel bearing.

[1738]

Originally Posted by DrewWphoto

Man this is the first forum I've been on that has so little interaction. Are BMW guys just less knowledgable about this stuff?

Nah unless you have a 335i no one here cares about anything you post.

[DrewWphoto]

Hahaha, I wanted one of those but kept on reading horror stories about their failures.

[Koogle1988]

More than likely a diff noise mine. Has the same exact whine. Been like this for 30,000 miles and hasn't changed. It's such a low pitched noise with a window open it cannot be heard. I check the fluids ever 10,000 for metal shaving nothing yet plus I don't really care until something explodes lol

[DrewWphoto]

Is there an easier way to check the transfer case without having to remove that cross member?

[Koogle1988]

What you can do it get a car stethoscope put the car up on a lift turn off the traction control have some one drive it. And listen to all the drive line components to see which one is making the noise. The whine sound I have is in the front of the car. When I changed my fluids they where all clean and looked perfect. I changed all my drive line fluids to royal purple 75-180 thicker oil and added liquid Molly which is suppose to help quiet loud diffs. Realize this won't fix the issue maybe quiet it down. But I drive my car the noise hasn't changed and there's no metal shavings so I just love with it until something actually happens. From reading Bmw tsb they would usually replace a diff after the added a thicker oil to see if it made it quiet but obviously my car isn't under warranty let me know if you have any questions

[DrewWphoto]

Do you mean 75-140 royal purple? I'll give that a shot and see what happens. I hope it keeps it running well for at least a couple years before I sell it.

[Koogle1988]

Yess my bad for the typo. 75-140 is what I used in both diffs. Then I used royal purple synchromax for the transmission and Bmw specific fluid for the transfer case. Some say the transfer case needs to be reset after this I did not have mine done and have had no issues or problems at all

[DrewWphoto]

So did putting the thicker oil in quite it down?

[Koogle1988]

Not really honestly it's always been the same noise for 30,000. I would have figured by now something would have let loose but has not

[DrewWphoto]

alright added a video of the noise to the original post.

[ajsalida]

Originally Posted by DrewWphoto

alright added a video of the noise to the original post.

Did the noise start after getting hit in front?