[e90yyc]

Pulled the front driveshaft... Vibration and noise persists. U-joints on driveshaft *appear* to be okay. More info at bottom of thread.

Noise suddenly appeared last night., though I was previously able to hear some cyclical noise from the same area. Prior to last night, however, it sounded a lot more like tire noise and wasn't very easy to pick up. It was also a much lower frequency, and was the type of noise in my experience was not worth trying to chase down. Now that it's gotten worse, I obviously need to address this. Hoping you guys can help.

I smashed into a terrible pothole on same wheel (front P/S) about a month ago and bulged my sidewall. Got two new tires, but rotated the new ones onto back, lest I hit another pothole. Because I was already hearing a noise from this area (above) prior to the incident, I'm hesitant to think they're related. There was no noticeable change in noise after the pothole incident.


Relevant facts:

• 2007 328xi with ~200k miles
• Noise is tied to wheel speed, but does seem to respond a bit to throttle input (letting off and then getting back onto throttle seems to make it louder, if only temporarily)
• Recently flushed brake fluid (don't see how taking wheels off/putting on could have caused this. Torqued all wheels to spec but will re-check them as soon as I'm able)
• Front wheel bearings, front shocks, shock mounts, supporting hardware all replaced about a year ago (all OE components; non-sport suspension)
• Recently rotated tires front/back and thought this noise (which was very hard to detect and of a different pitch, until now...) seemed to be more noticeable, but I don't see how the tire rotation would affect it
• Steering side-to-side seems to have no effect
• When I start driving from a standstill, there is usually a dull popping sound (almost like a stuck brake caliper releasing...) that can be heard after a few feet of rollout. This is new and started with the noise in attached video.
• CV axles are original AFAIK; boots appear to be intact
• All other suspension components are original: control arms, bushings, etc...

I think the video makes it clearer than I can, but it's almost like a "whum whum" sound. (In the video it actually sounds a bit higher-pitched than it really is; can post another vid if it isn't clear...) The recent post from someone whose car sounded like a "choppah" only to shit its guts all over the highway did make me a bit concerned.

It's clearly coming from P/S front wheel area. Can be felt a bit through steering wheel, but no major vibration.

Hope I've included enough info here. Let me know if any other details would help. I know noises are a PITA to diagnose over the forums, but hoping someone can point me in the right direction so I can address whatever is causing this. In light of what the poster experienced, I've told my girlfriend not to ask for any rides until this noise is addressed.

[Antetokounmpo]

I would pull you front drive shaft out (transfer case to front diff) and see if the noise persists.

[e90yyc]

Originally Posted by Antetokounmpo

I would pull you front drive shaft out (transfer case to front diff) and see if the noise persists.

I’ll look into this. Thanks for the suggestion.

[Antetokounmpo]

Originally Posted by e90yyc

I’ll look into this. Thanks for the suggestion.

I had a 1-2 year long noise issue, it wasn't as bad as yours but noticeable sometimes. My front drive shaft u-joint blew up one day and when I took it out and replaced it the noise was gone. Similar symptoms to yours.

[e90yyc]

Originally Posted by Antetokounmpo

I had a 1-2 year long noise issue, it wasn't as bad as yours but noticeable sometimes. My front drive shaft u-joint blew up one day and when I took it out and replaced it the noise was gone. Similar symptoms to yours.

Thanks man. I was worried this looked like a serious job, but it seems removing it is relatively straightforward.

I was definitely thinking something driveline related—maybe a CV joint, but the noise wasn't like what I'm used to hearing from a failing CV.

Definitely appreciate the suggestion!

[theslowe90]

Are you turning in that video? Cause that steering wheel is not very straight...

[e90yyc]

Originally Posted by theslowe90

Are you turning in that video? Cause that steering wheel is not very straight...

Yes, but the noise is present regardless of steering angle.

Alignment is good. Car tracks fine.

[e90yyc]

Any other areas I should be looking at when I go and pull the driveshaft?

Thanks!

[e90yyc]

Alright, sorry for all the replies to my own thread here. I'm really hoping for at least a couple more ideas of what this might be. I can't imagine there are very many possibilities, but maybe I'm wrong...

Originally Posted by Antetokounmpo

I had a 1-2 year long noise issue, it wasn't as bad as yours but noticeable sometimes. My front drive shaft u-joint blew up one day and when I took it out and replaced it the noise was gone. Similar symptoms to yours.

I pulled the driveshaft and the issue persists. Funny thing is on the drive to go do the work, the noise seems to have subsided a bit once again. Not as harsh of a knocking; more like what it used to be... a bit more subtle.

Before I pulled the driveshaft I ran the vehicle in drive with DSC off and wheels off ground. As wheel speed increased, there was a definite vibration that got worse as I increased speed. I let off the throttle once I had shifted to 5th and had probably run it up to about 50 mph.

Now that the driveshaft is off, I'm unable to run the car while lifted as the 4x4 system chucks a ton of errors even with DSC off. When on the ground it drives fine, but that noise and vibration are still there...

Any other ideas man? I was also mistaken in believing the driveshaft was on the passenger side... I see now I had the parts diagram orientation incorrect. The only other diagnostic I can think of at this point is to have someone else sit in the car and run it while I look at the P/S axle.

Thanks in advance.

[Efthreeoh]

Axle shaft or wheel bearing would be my guess.

You saw the thread of the member who ignored his front driveshaft and blew a hole in the oil pan?...

[e90yyc]

Originally Posted by Efthreeoh

Axle shaft or wheel bearing would be my guess.

You saw the thread of the member who ignored his front driveshaft and blew a hole in the oil pan?...

From my original post above

Originally Posted by e90yyc

The recent post from someone whose car sounded like a "choppah" only to shit its guts all over the highway did make me a bit concerned....

...In light of what the poster experienced, I've told my girlfriend not to ask for any rides until this noise is addressed.

I replaced the front wheel bearings about 10k miles ago. What a pain in the ass. Definitely hope they aren't the culprit, but like you, I'm thinking axle at this point too.

Just wanted to get some second opinions, so thanks as always for your help.

[mecheng77]

Cv joint is typically only when you turn and if these cars have gkn axels they are the best and I would never trade them for a new cheap axel, rebuild the boot yourself

Bearings have rhythmic noise it could have been damaged with the hit. Or maybe you have a bad tire, try swapping a winter tire on.

[e90yyc]

Originally Posted by mecheng77

Cv joint is typically only when you turn and if these cars have gkn axels they are the best and I would never trade them for a new cheap axel, rebuild the boot yourself

Bearings have rhythmic noise it could have been damaged with the hit. Or maybe you have a bad tire, try swapping a winter tire on.

Thanks for the input!

I don't see how it could be a wheel bearing. Not only are they next-to-new, but this noise was already present prior to wheel bearing replacement, just becoming louder recently. I will take your suggestion of swapping the tires though. Worth a try at least.

I had run the car with the wheels up and noticed quite a strong vibration from the front. I don't see any way it could be a bearing as the rotating mass is way too small to result in a vibration like what I felt. An axle on the other hand absolutely could have caused what I felt. (I did have the front wheels off too, so it wasn't a wheel balance issue.)

[Antetokounmpo]

It definitely sounds like it's wheel speed, so my theory of the front drive shaft wouldn't hold up anyways. At least it's an easy check. That pretty much leaves you with the half shaft or wheel bearing. How did you install the wheel bearing? If you press too much on the inner race while installing it definitely could've been damaged. How old are half shafts?

[e90yyc]

Originally Posted by Antetokounmpo

It definitely sounds like it's wheel speed, so my theory of the front drive shaft wouldn't hold up anyways. At least it's an easy check. That pretty much leaves you with the half shaft or wheel bearing. How did you install the wheel bearing? If you press too much on the inner race while installing it definitely could've been damaged. How old are half shafts?

Ah okay, good to know!

Bearings were installed at a friend’s shop, but the noise was present prior to doing them, so I don’t think they are to blame.

I wonder whether my control arms don’t have something to do with this... they are original and the car has over 200k miles, and there are some very clear signs they are shot.

Next step for me is going to be getting the wheels back up in the air and having an assistant run the car up to speed while I observe the front wheel areas. I noticed vibrations when I did that last time, but was working alone so there was no way for me to tell what it was. Tried putting my phone there to record a video but didn’t help...

I just really don’t want to replace anything that doesn’t need replacing, so if I start with my control arms and tie rods—which need to be replaced without a doubt—then at least I’m not throwing money away. I suppose if I already have control arms off then replacing the axles wouldn’t be much more work, but I need to be 100% certain before I do that. I’ll also swap my tires front to rear and see if anything changes.