Knocking noise coming from front?

[3002 tii]

Noticed a front knocking or clunking noise when I back up, brake and go forward. Checked shock mounts, those are fine. I've searched around and I've seen this issue come up before but no definitive answer. Car is on stock suspension and has roughly 33k.

Only thing I noticed was the spring (oem) looks like it's hanging off the perch, although perch itself doesn't appear to be flat... is that normal?

The shop I had it with said it could also be control arms? They showed me an oem pair that came off the 7-series and the bushings looked cracked. Oh yea they said it could also be the ball joints?

[3002 tii]

Also found this

http://wwww.bimmerfest.com/forums/sh...=238680&page=7

[apexstrafer]

The front end clunk is most likely attributable to your strut brace.

Either one of the fasteners isn't torqued down or you have a cracked mounting bracket on one of your strut towers. Mine cracked at the weld on the driver's side after hitting a pothole. Had a local race shop weld it up better than factory and haven't had an issue since.

EDIT: Just realized you have a non-M; not sure if the above applies to you or not.

[Lance_Goodthrust]

My 3.0si had a clunk in the front when I went over small bumps.
I torqued down the strut braces, clunk gone.

[3002 tii]

But this happens on flat surfaces, and only when I reverse, brake and then gas forward...

[ZStig]

Originally Posted by apexstrafer

The front end clunk is most likely attributable to your strut brace.

Either one of the fasteners isn't torqued down or you have a cracked mounting bracket on one of your strut towers. Mine cracked at the weld on the driver's side after hitting a pothole. Had a local race shop weld it up better than factory and haven't had an issue since.

EDIT: Just realized you have a non-M; not sure if the above applies to you or not.

it applies, and its a common problem. Also they need to be checked with a wrench, because sometime even if they feel tight by hand, they're still lose

[3002 tii]

Originally Posted by Roffle Waffle

it applies, and its a common problem. Also they need to be checked with a wrench, because sometime even if they feel tight by hand, they're still lose

interesting, because I did tighten the brace down but the sound still persisted afterwards.

i took a video with my iphone but unfortunately i don't have quicktime pro so i can't rotate the movie LOL, but the sound is most important. everytime i put the car in gear and go back/fwd you hear a clunk noise

[thekurgan]

Are you sure it's not your brake pads?

[ZStig]

the two cross braces coming from the strut towers, right?

[chanzs]

Have the same noise, checked the strut bars and sure enough, both nuts at firewall were loose. Haven't gone for a test drive yet but fingers crossed.

Update: Problem solved!!!

[filtercoffee]

Had a creaking or squeaking noise that seemed to come from inside the dash, it turned out to be this issue. Tightened the bolts near the firewall, one was noticeably loose. The noise is gone - and I'm not sure if this is placebo effect - the car even feels more solid. Best bang for buck fix ever - took 30 seconds and made the car feel new.

[elerner61]

For an M, what is the torque spec for those bolts?

[StickMon]

I think 30 ft*lbs (41 Nm).

[Tonester308]

Had the same noise on my newly acquired 2006 Z4... torqued up the braces and problem solved. Thanks.
P.S. New to forum... very helpful!

[Boosted 1]

I had the same prob as OP. Torqued braces, changed fcab, check top mounts, inspected end links. I just changed front control arms and it fixed it. It was worn ball joints. No more clunking!!!!

[Huz-Z]

Originally Posted by Tonester308

Had the same noise on my newly acquired 2006 Z4... torqued up the braces and problem solved. Thanks.
P.S. New to forum... very helpful!

Welcome!!!

[txguy1986]

I just bought my Z4 on Saturday and heard that knocking when I test drove it. I thought sure I was going to need to replace a control arm or something major. I tightened to two cross bars and no knocking!!! Thank you. I wish the power top had an equally easy solution to fix. LOL

[ANILE8]

I have the same thing with a noise coming from the centre part of the dash over bumps. It is driving me

I have fully tightened the strut braces to 75ft-lbs but still, the noise is there.

When I remove the strut braces the noise is gone.

I have checked the welds on the strut towers and they look fine.

I have removed the cowling covering the firewall brace and inspected the bracket and it all looks good.

Does anyone know what this could mean?

[DerE85Fahrer]

I had a knocking noise before I redid my front end. It was really only noticeable at low speeds in 1st or 2nd gear, and was inconsistent. I replaced my front control arms and bushings, and the noise got worse. It turned out to be my sway bar end links, which would only clunk if I hit a bump in such a way that the two front wheels moved independently, such as when going over a speed bump at an angle. I was able to recreate the noise by rocking the front of the car and compressing the suspension only on one side.

[ANILE8]

I have found that it only happens with the left strut brace in place.

If I remove the left strut brace the noise stops.

Not sure why as all the bolts are tight.

[thrak410]

So, I was having a similar noise/creaking/clunking issue and everything was tight up top, however!! I discovered the sub-frame brace on the bottom was missing bolts, and others were loose.



I replaced the bolts that were missing and tightened everything up and it completely fixed it. I even have new FCABs ready to go on, but mine looked ok (115k miles).

I'm considering an ultra racing brace here (if they make one), since this is some super thin metal, and I'm EXTREMELY pleased with the quality of the rear sub brace and strut tower brace from them, and we all know roadsters can use all the chassis stiffening they can get.

[zimmer]

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