Help - clunking from front axle at low speed

[cps26]

Hello all

I wonder if someone might be able to offer some advice / ideas on this problem... We're on the first day of our planned Europe roadtrip - done 360 miles today on autoroutes, pretty much all of it at c. 80mph. Car has been great - BUT - pulling into the town for our first night's stop, there is quite a pronounced rhythmic 'clunk' from somewhere on the front axle / under the bonnet - it's most noticeable at low speeds but I think it is there all the time. Walking along beside the car, it can be heard, and it is in time with the revolution of the wheel - 2 clunks per revolution (kind of 'tick tock' if you know what I mean). Doesn't seem to be coming from one side more than the other so don't think it is the brake calipers / disks.

I saw this thread (http://www.z4-forum.com/forum/viewtopic.php?f=9&t=55946) - our car is Bing's old car, so this could be the same thing, but I don't know whether the clunk described on that thread was linked to the wheel rotation - this one very definitely is.

Any ideas and suggestions gratefully received! We're in a small town in France which I think has a BMW dealer in it; presumably shut tomorrow though; hopefully we could find some kind of mechanic somewhere even if on Monday (we have breakdown cover) but would be excellent if anyone has any thoughts as to what it might be! :?

Cheers,

Chris

 

[BrianD]

Have you checked the metal shield around the front brake disks hasn't worked loose, or anything stuck in the pads?

Could also be a worn wheel bearing or CV joint, my guess is a wheel bearing.

 

[Bing]

Chris - that clunk/creak on the thread above was only in situations where the chassis twisted slightly at low speed, so reversing out my drive or occasionally going up/round ramps in multi-story car parks. It came from behind the dash and was solved by tightening the braces. I've never experienced what you describe when driving the car, and don't know what it could be. No mention of wheel bearings was made when it had it's Insp 2 recently, but I guess at 96k miles it could be something like that. Really hope it's nothing serious

 

[cps26]

Thanks Allan - useful to confirm it isn't the same thing you had with the strut brace.

I think this morning we will go for a drive in the direction we were planning to go anyway and see what happens. My hunch is that it might only manifest itself when the car is fully warmed up - driving the car a short distance last night after dinner didn't reveal it, and we only noticed it after lunch yesterday after a long, fast autoroute run. It's definitely quite a percussive, tapping sound, twice per wheel revolution, so I wonder if it doesn't quite fit with being a wheel bearing type sound, which I've seen described as a kind of "whish whish whish" noise?...

If it comes back I'll try to get a video of it and post it on YouTube or similar in case that helps identify it at all.

 

[jan_tekin]

Don't think it's a wheel bearing, unless the noise it apparent whilst making a turn,where the weight is placed on that wheel.




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[cps26]

Thanks Jan - no, the noise is constant; doesn't seem to change on turning. It did seem to go away briefly after a couple of emergency type stops from c. 20mph, but then came back again within 30 seconds or so after that...

 

[BrianD]

Does the sound vary in speed depending on how fast the car is going?

 

[cps26]

Hello all - quick update - I managed to get some video of the noise from running along beside the car - have put it on YouTube here: http://www.youtube.com/watch?v=L2_UIREF834

Will write a longer post in a mo with some more details of the "symptoms" but thought I'd post this as running low on phone juice (camping tonight...)

 

[cps26]

So - a quick write up of today's drive in case it gives anyone any clues...!

Set off this morning; car was cold from overnight; no sign of the noise. First 80 miles or so were sort of flowing A roads - 60 mph stretches mixed with 30mph through villages. Even after a couple of hours of this; no noise.

We then got back on an autoroute and spent maybe 45 min at 80mph. Coming off into a fuel station, the noise was back; that was when the film was taken. After that point, although we went back to the more relaxed mode of driving, it was still there.

So it seems to only come on when the car is properly hot - not just warmed up. It is definitely linked to wheel rotation speed. It does seem to increase somewhat when on full lock (left more than right ) but is present going straight was well. I think if anything it has worsened during the afternoon - quite audible from outside the car driving past (though you don't here it above about 25 mph; think it just blends with the engine : tyre noise then.

It also does seem to come from both sides - though my shouted comment on the video may suggest it is one side, it was on the other as well.

So... Any further thoughts on what it might be?! Also, any ideas / advice on what the best course of action might be? We're near Aix les Bains, where I think there is a bmw dealer who should be open tomorrow. We can take it there (though it may not be doing it without a run first!) But any other thoughts welcome. We have breakdown cover but I'm not sure this counts as something to call them out about as the car is still drivable (dunno if it is doing any harm driving it though!)

Cheers all,

Chris

 

[cps26]

Got a bit more data now so here here is a slightly longer / better clip - http://www.youtube.com/watch?v=6lh_07LT740

As you can see, is definitely with the rotation of the wheel. Thinking about it, I reckon the reason why it is worse on full lock going left is simply that the right wheel (which is the noisiest) is having to rotate more?

 

[RJS-Z4]

OK so have you checked the basics?

Wheel nuts, sounds obvious, but it's entirely possible that they're loose for any number of reasons.

Caliper bolts, given that it's so rotational, it could well be a now slightly warped discs and a loose caliper?


My next move would to to remove the wheel, grab the disc assembly, and give everything a good shake.

If you're still not getting anything, then it could be a particularly quirky bearing failure.

Then I'd be considering the front arm, I can't quite figure out how you'd end up with such a rhythmic knock from knackard balljoints/bushes, but it's the only way to go about it.

 

[cps26]

Thanks RJS. Wheel nuts seem ok (though admittedly I've not got a wheel brace to check with...) where are the calliper bolts - is that something I can check with the wheel still on?

 

[RJS-Z4]

Caliper bolts will need the wheel off.

If you've not even checked the basics, I'd jack that side of the car up, grab the wheel and see if you get any movement in any direction.

 

[cps26]

Thanks for all the help on here - problem is now solved...

Turns out the wheel nuts were very slightly loose - presumably this only manifested itself when everything got really hot and expanded differentially some how? Anyway, obviously we had no wheel brace given the original fit RfT, but a trip to the bmw dealers in Chambery sorted it - they checked it on the ramp, diagnosed the problem and tightened them up, all free of charge - very decent of them

Have now bought a wheel brace from the French equivalent of Halfords so will check them every 500 miles or so.

Thanks again for all the help on here - really appreciate it!

 

[hopz121]

Glad it’s all sorted and it was a free fix, you were mega lucky that it didn’t go horribly wrong and the wheel fall off ending in a crash. Always important to check your nuts on a regular basis

 

[Bing]

Really glad it's fixed Chris, and a simple solution - wasn't something I checked after the last time the wheels were off at it's service, sorry about that

Note to self - check mine at the weekend. Wheel bolt torque is 120nm for future reference.

Enjoy the rest of the trip - and get some pics up soon oke:

 

[RJS-Z4]

Blimey, at least you learnt a valuable lesson to keep a breaker bar in the boot!

Also bare in mind that wheels can come loose for all manner of reasons, even down to someone considering having a go at having them away and being disturbed.

 

[cps26]

Thanks! Yes, it was a good thing we didn't just carry on

Will put some pics up though it may have to wait till we're back as only have 'i' devices with us so no way to upload anything from a camera... Had a fantastic drive over the col du Mont Cenis and might have some decent gopro footage of that as well...

 

[-Tom-]

Wow glad you found that this way and not any other way! And you can get enjoying the zed again! Bing, I wouldn't have checked that after a service dither - kind of bread and butter thing you expect to be right, they normally do them up too tight!

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[Bing]

I think you're supposed to re-torque them after a 500 miles or something like that - not sure I went that far after the service but I forgot anyway