[pits200]

Purchased a 2009 335i Xdrive about 1 month ago with 6.5k miles on the odometer from a BMW dealership. I purchased the car sight unseen like I have with the past 5 cars my wife and I have purchased. We have only bought from dealerships in the past and have had excellent experiences.

So when I got the car, the engine sounded strong and the car appeared to be taken care of. Car had a clean carfax, there was a small bumper repair but it was all cosmetic.

After a day of driving I noticed that speeds of 60 to 80mph the car would vibrate. If felt like an out of balance tire so I went to the dealership after my trip and they balanced the tires but the problem still was there. After swapping out the rims/tires on my car with a set the dealership had laying around, the problem still was there which ruled out the tires.

As of now, the dealership has done the following:
1.) Replaced driver side axle
2.) Replaced differential
3.) Replaced Motor Mounts
4.) Replaced rotors
5.) Replaced passenger side axle
6.) Replaced drivers side hub assembly
7.) Tires have been balanced on a hunter roadforce machine
8.) Tires/rims have been swapped to determine if it was a tire/rim issue and the problem was still there.
9.) An alignment was completed.

After all of this, the problem still is occurring and they are moving on to the transaxle then to the engine.

Symptoms:
1.) Vibrating from 60-80 whether Im accelerating, coasting, or braking
2.) It is felt in the seat, if you put your head on the headrest, it feels like a harsh massage.
3.) The car accelerates/cruises smoothly from 0-60, no clunks, no thumps, no shuddering or vibrating.
4.) Brakes are smooth, no vibrating during braking.
5.) Car gets good gas mileage
6.) Makes no whistling or grinding sound indicating a wheel bearing.
7.) Car throws no codes

So please help if you have any suggestions.

[Tortfeasor 335xi]

Wheel bearings perhaps? Worn wheel bearings can cause vibrations while driving. The fact that its at a particular speed though makes me think that its a wheel out of balance. Have you tried getting the wheels balanced by someone other than the dealer? They might just suck at balancing...

[pits200]

They have a hunter roadforce machine there which is pretty much idiot proof and very accurate.

In addition, they actually removed my tires/rims and replaced them with a brand new set of balanced rims and the exact same problem was still there.

As for the wheel bearings, the car only has like 7k on the odometer now..

Ah gees, least its all covered under warranty.

[gun6slinger9]

it might be as simple as a warped wheel? with only a small deformity it might take the high speeds to notice anything.

[ctuna]

Have somebody drive another car beside you and see if anything can be seen
visually . Mount camera to the underside pointed at the suspected parts.

[Ltran]

335?.....HPFP.

[fdriller9]

Bushings? Although with your low mileage, your bushings should be fine....for at least another 40K. However even with a car fax you don't know if the previous owner had done any suspension mods that could have accelerated wear on your bushings.

Sounds like you haven't tried an alignment?

[fdriller9]

Originally Posted by Ltran

335?.....HPFP.

Way to read the OPs thread...it has nothing to with the engine or fuel system for that matter.

Quick question? Are you even associated with Long Tran? I though his dealer was in CA?

[J02 335i]

Sounds like the front driveshaft (from transfer case to front diff) is out of balance. Tell them to replace it and I bet your problem is gone. Or even the rear driveshaft for that matter. Or both.

[Ltran]

It was a joke.....way to see pass the sarcasm.

Quicker answer, NO.

[pits200]

Whoops, forgot to mention.

Yes an alignment was done, I'll edit the original post.

Thanks for all the input so far.

As for mods being done to the car prior. It was a demo car that the gm of the BMW dealership drove. So I can say with strong confidence that the car most likely wasn't modded.

[fdriller9]

Originally Posted by pits200

Whoops, forgot to mention.

Yes an alignment was done, I'll edit the original post.

Thanks for all the input so far.

As for mods being done to the car prior. It was a demo car that the gm of the BMW dealership drove. So I can say with strong confidence that the car most likely wasn't modded.

Ltran...read through it quickly, my bad.

Doesn't matter if God drove it....there was a post a while back on the M5 board that described a situation where a BMW employee totaled a customers car. And the dealer tried to cover it up and make the customer pay $1500, IIRC. Which "coincidentally" was the insurance deductible for the dealer.

[Ltran]

It's cool *********.

Once again all is right in the world.

[pits200]

Im agreeing with JO2 that its one of the drive shafts. They are going to call and give me updates every 2 or 3 days. The car has been worked on for the past 3 weeks and they are still baffled.

[Xpander]

Chief,

"It is felt in the seat, if you put your head on the headrest, it feels like a harsh massage."

Did you check that your seat is bolted down correctly? Won't hurt

[pits200]

Originally Posted by Xpander

Chief,

"It is felt in the seat, if you put your head on the headrest, it feels like a harsh massage."

Did you check that your seat is bolted down correctly? Won't hurt

Thats the kinda thinking I like, outside the box.

But the vibration kind of goes away over 80mph, if it was just the seat, id assume it would be there at all speeds.

The problem is also felt in the steerin wheel but not horribly.

[Xpander]

Not necessarily. Every mass/force system tends to have a natural frequency at which it is excited to resonance. In your case, the resonance might occur at 60-80 mph. If one or all the screws holding the seat are not tight enough, you might experience the resonnant vibration. Just my nerdy 2 cents

The steering wheel vibration, though, doesn't fit my analysis

Good luck.

[Healey3000]

Hi,

I had a car once that exhibited similar behavior. I finally took it to a specialist suspension shop in my area (Custom Alignment, Mountain View, CA) and after a little study, they figured that the wheels needed to be balanced on the car.

Regular balancing on a machine with the wheel off the car didn't pick it up. Not sure how they do on-car balancing but it completely cured the problem.

Any rotating mass can contribute so the idea that has been floated of bad axles may be part of the problem.

Please let us know what you find.

Regards,
Adnan

[brocken]

Originally Posted by J02 335i

Sounds like the front driveshaft (from transfer case to front diff) is out of balance. Tell them to replace it and I bet your problem is gone. Or even the rear driveshaft for that matter. Or both.

^This

I had a similar problem on my '67 Bronco ( i know, completely different vehicles). The problem only occured over 60 mph when cruising or if I let off the gas. I replaced the 43 year old driveshaft with a new, balanced one and now it's super smooth on the highway.
I also had really bad wobbling over 40 mph before that which was fixed with new tires (old ones had flat spots) and new front end bushings. That was a different type of feeling though.

The problem you're describing and speed at which it happens definitely sounds like a driveshaft issue.

[Kolyan2k]

Vibrations are hard to troubleshot.....Maybe the accident was bigger then you think, something moves 1mm and there you go.....I traded-in my Audi, started to have weird vibrations after a not so big accident....

glad to hear they are replacing stuff for you......

[nogard13]

I was going to post the driveshaft as a possibility but someone beat me to it.

I would also check the rear axle, not just the front. I was also thinking bad gear in your differential but I see that was replaced. The parts that have been replaced, as well as the symptoms, point towards being drive shaft related, IMHO.

[kanecvl]

Can passengers feel it?