***Mystery Vibration Noise..HEEELP!****

I bet no one can figure out this issue I have. As the dealership says there no visible damage to rim or tire.

Front driver side wheel, 2008 335i sport package, 12K miles, w/ stock 18" rims and blizzaks snow tires on at time of impact.

I hit a significant raised crack (like a raised bump) at 70 mph on the highway. Straight on and immediately got a vibration sound after impact. Similar to this sound: Wow...*****...***** (1 sec gaps). The noise is loudest while driving at, you guest it, 70mph. It happens while driving straight and.....

I changed all rims w/ stock run flat tires, to a brand new set and the vibration is quieter..but still there. Alignment seems good as the car does not pull in any direction at all.

When you go through a bank turn right, the vibration noise is louder and increases in frequency like: wow.*****.*****. (weight is on the bad tire/rim) There is a bit of vibration in the steering wheel that is more noticeable during the right hand bank turn.

Now, when you have a bank turn to the left (weight off the front driver side wheel) the vibration noise almost completely goes away.

What could be causing this vibration and annoying noise?

Could this be a bad wheel bearing? Could it be a bad control arm or suspension?

I am at a loss and appreciate any of your help. I am so frustrated that the post that get's this one right will receive a $50 gift card as a thank you. (paypal works as well)

Thanks -Don D. from Chicago (soon to move because these f-ing roads are ridiculous here)

Sound is like, wow--wow--wow.

Anyone have any ideas???

When you hit the bump, did it hit all four tires?
Did the dealership remove the tires from the rims or put them on a balancing machine?
Did you/dealer check the tires for bubbles?
When you changed the tires, were these on new rims also?
Does the frequency increase with speed?
At what speed do you start to hear the noise? If the frequency is independent of speed, I would be inclined to think it is something to do with the suspension/steering.
Any loose body panels in the area? Perhaps the airflow is causing a loose panel to vibrate...

The key word is "visible". You should make sure the run out on the wheels is carefully measured. If your dealer won't do this, take it to a wheel repair shop. I would also look at the wheel bearings, but it takes a lot to damage them. You're right about the Chicago area roads. I've put 17's on my 335 with Bridgestone RE960AS Pole Positions. I really like the performance of these. Very responsive and surprisingly sticky. Also, no pothole explosions since installing them.

Good morning DJD. Your symptoms and when they occur/don't occur match wheel bearing failure symptoms. But it is very rare for wheel bearings to be damaged by impact without having significant damage to other components as well. I haven't had the chance to take a look at the bearing from a 335i, bearings are usually quite robust and not prone to compression damage. That said, I have read on this board of others who have reported bearing damage from potholes.
What we do at my shop is use a device called a 'Chassis Ear' to locate noise sources. Remote microphones are attached in various areas and the tech drives the car with earphones on, listening to the mics by selecting each in turn on a master control.
You might want to find an independent shop which has the right equipment to diagnose your problem. Dealership techs hate this kind of work because the 'flat rate' isn't a line item in their flat rate book and SA's don't usually quote enough diagnostic time. So the tech's paycheck ends up taking a hit unless he blows the job out the door. And then you end up in the situation you're in.
Edit: If you hear a bad bearing using a screwdriver handle, a mechanic's stethoscope or a Chassis Ear the sound is unmistakable. It is a low pitched (kind of like you might imagine a lion would purr) rrrrrRRRRrrrrrrRRRRRRrrrrrrrRRRRRR which is in perfect time with wheel rotation. If the car is suspended in the air the sound is lower in volume than when the bearing is on the ground (loaded). Additionally, front tires have to be spun by hand as opposed to the rears which can be 'driven' while up in the air.

All...thanks for the posts and here's some answers to ucdbeindog:

I'll be taking my car over to my independent mechanic who is the best I've found. I'll update what we find---here's the answers to your questions:
------------
When you hit the bump, did it hit all four tires? Yes, but there was a more raised crack/bump on the left side.

Did the dealership remove the tires from the rims or put them on a balancing machine?

"My very close friend manages a Just Tires Store and we put new tires on and used new OEM rims. Everything is balanced and true. They do ride smooth--but that frickin' vibration noise is still coming from the front left wheel."

Did you/dealer check the tires for bubbles?
"Yes. Tires are all good."

When you changed the tires, were these on new rims also?
"Yes, everything new."

Does the frequency increase with speed?

"No. But the frequency increases when you turn right and pressure is applied to the front right wheel. (strange to me)"

At what speed do you start to hear the noise? If the frequency is independent of speed, I would be inclined to think it is something to do with the suspension/steering.

"It starts at about 45MPH...but is most noticeable and loudest at 70MPH".
Any loose body panels in the area? Perhaps the airflow is causing a loose panel to vibrate...

I'd first swap the left and right wheels to eliminate a bent wheel as a suspect. If the problem is still there I'd focus on the left (i.e., driver's side) strut and spring. Maybe the spring broke or the strut sustained some damage. The low frequency nature of the problem and the banking behavior you describe would lead me down that path. I'd also take a look at the left tie rod. Maybe something happend to the ball joint there.

Also, see how it behaves over a speed bump. Try going over a speed bump so that only one side is going over the bump (and then repeat with the other side). Maybe that will yield some clues.

One more thing. A slalom test at various speeds could also give some clues.

All, this mystery issue is still being investigated slowly by me: I've swapped all wheels and tires as described and also got the BMW dealership to swap the driver side front wheel bearing/hub assembly, but they won't couldn't commit to doing both for no charge. It is now quieter, but I am still getting the low frequency hum from the passenger front wheel.

I am thinking about paying $300 bucks to just swap the passenger front wheel bearing/hub assembly and eliminate that variable.

Thank you for the posts and I'll be looking into spring, ball joint, and tie rods.

Update to follow in a month.

-DD

Originally Posted by DJD33

All, this mystery issue is still being investigated slowly by me: I've swapped all wheels and tires as described and also got the BMW dealership to swap the driver side front wheel bearing/hub assembly, but they won't couldn't commit to doing both for no charge. It is now quieter, but I am still getting the low frequency hum from the passenger front wheel.

I am thinking about paying $300 bucks to just swap the passenger front wheel bearing/hub assembly and eliminate that variable.

Thank you for the posts and I'll be looking into spring, ball joint, and tie rods.

Update to follow in a month.

-DD

So changing the driver's side wheel bearing lessened the noise on that side...but the passenger side is 'talking' some. Seems time to change the wheel bearing on that side also.

This is crazy that a road imperfection would wipe out both front wheel bearings without bending other parts! You did say the alignment was checked as good, right?

Brian

The front rims actually did get a little ding/bent after the impact. I had the alignment done and new set of rims put on since.

I am almost ready to change that last front right wheel bearing hub assembly and I'll update. I've been waiting to get out of the Chicago loop living before I do this one.

Update to follow and thanks for the posts on this.

DD

I wanted to share the resolution of this matter with everyone.

A great BMW service adviser was able to get both the front wheel bearing assemblies replaced for me at no charge (BMW no charge maintenance still in effect).

This got rid of the annoying oscillating noise I mentioned.

If you ever see a nice crack in the road: It's best not to hit your brakes while going over it as it shifts all the weight of your car on those front wheels and makes them more susceptible to damage. I know...this is 101, but when you make a quick panic brake to avoid the crack...you can worsen the outcome (my case).

Try to break prior and release prior to the crack/pot hole. (challenging at 85 mph)

Thank you for everyone's posts on this.

-Don D.