Loud snapping sound in the dashboard

An update. I tightened the nuts on the cross strut braces. That eliminated the sound for about two days, but now it's back. I'm sure the threads on the bolts are worn out or something. Guess I'll have to take it to the dealer. :thumbsdown:

I am getting the OEM strut brace though so hopefully that might solve the problem, but I'd like the dealer to fix my cross strut braces as well.
 
If you like the visual effect of the strut brace go for it! But it won't be so useful...
You will resolve the issue simply replacing the bolts exactly in the way the document you posted says :thumbsup:
Everything there was previewed :wink:
 
screenshot01sl4.jpg


:)
 
Update:

I took my Zed in to the dealer today. They couldn't reproduce the sound. I drove my Zed with the tech in the passenger seat for 5-10 minutes and couldn't reproduce it. Damn it! So they're not gonna try to fix it.

I ordered the bolts from BMW a couple of weeks ago and replaced the strut brace bolts myself and installed the OEM strut brace (thanks, intgr8r!). But the sound is still there. The annoying thing is, I can drive for half an hour and never hear it, and then another time I'll drive for 10 minutes and hear the snapping noise 4 or 5 times.

Oh well. At least the dealer offered to try it out again in a couple of weeks when I bring my Zed back to replace the passenger headlight.
 
...I too was hearing a similar type of sound with my Zed, and it only occured when I was pulling the car out the garage and onto the driveway. Fortunately for me, and from reading the earlier posts on this thread, I also discovered that I had loose strut bar bolt, so I tightended it and there has been no clunking sound since... :thumbsup:

Anyways, good luck and I hope you find the source of this problem....
 
I had a similar sound coming from a similar place on my Alpina. Turned out to be a broken weld on the bulkhead/firewall. I don't want to panic anyone but the dealer said it's quite common, they even have a repair kit to deal with the problem. It was a huge repair job which involved removing the dashboard etc and my car was at the dealer for three weeks. :(
 
Curtis said:
I had a similar sound coming from a similar place on my Alpina. Turned out to be a broken weld on the bulkhead/firewall. I don't want to panic anyone but the dealer said it's quite common, they even have a repair kit to deal with the problem. It was a huge repair job which involved removing the dashboard etc and my car was at the dealer for three weeks. :(
Click to expand...
Very strange that we haven't heard more about this....
Do you have any more info on the specific location on the firewall????
 
Curtis said:
I had a similar sound coming from a similar place on my Alpina. Turned out to be a broken weld on the bulkhead/firewall. I don't want to panic anyone but the dealer said it's quite common, they even have a repair kit to deal with the problem. It was a huge repair job which involved removing the dashboard etc and my car was at the dealer for three weeks. :(
Click to expand...

What?! Can you give us a description of what your sound was like? How often? When would it happen, etc.?
 
The sound was very much like the sound from the strut braces, I had the strut brace problem originally and had this fixed, a few months later when a similar sound appeard I assumed it was the same thing but unfortunately it wasn't! It was a cracking noise that happenened when either I went over a bump or compression in the road or sometimes during sharp cornering. Lucky for me the car was under warranty at the time.

The repair kit consisted of a preformed metal plate to reinforce the offending area and several rubber seals. The dash was completely removed as was all the soundproofing, pipework etc from the engine bay side of the bulkhead. The repair kit was on back order at the time so I would assume I wasn't the first to have this problem. The fact that they have a repair kit already made for it would tend to back up this theory. I can't tell you the exact location of the weld unfortunately, I just let them get on with it and didn't get too involved at the time. Hope this isn't your problem but it's certainly a possibility.
 
How often would you hear the sound? The problem with mine is that it's not that predictible. If it does happen, it's usually associated with a bump, but I can run over 50 bumps and hear it once or 4 or 5 times.

The tech I spoke to said that if it was a strut brace issue, then the sound would occur consistently and frequently.
 
The sound occured just about every time I hit a decent sized bump or took a fast bend, it didn't seem to happen on general rough road surfaces or maybe I didn't hear it over the interior trim rattles! Both problems only happened when the bodyshell flexed considerably. Your best bet is to retorque the strut braces and keep your fingers crossed!
 
maybe it's the control arm bushings?? just a thought..

i ended up getting new control arms for both sides and new bushings. it costed me about 2 or 3 hundred dollars.

that's my best guess*
 
Tom,

Those bolts are 'one time use' bolts and must be torqued to the proper spec, then 'angle torqued' by rotating an additional 90'.
 
Cracking thread again :thumbsup: I've just checked my nuts :oops: and found the two on the top of the brace were loose, I gingerly re-torqued them well below spec and the dammed chirping from the dash has been cured, and the car feels a little more 'solid' (could be placebo affect) either way, fantastic :D

These are actually studs and nuts, not bolts, I'll get some new onces pronto.

Following on from Shipkillers comments above I would stress the same, HT studs are designed to be stretched in situ once and re-set after a short period. So don't re-torque these studs to spec' again, particularly not the 27 NM mentioned in Albertoxx's post on page 2 above, they are likely to break and cause a world of fuss to remove. I'm reading those technical comments to mean that BMW upped the spec of later studs to 27 NM ? Hence don't go near that figure if re-tightening originals. Note that if you re-torque HT studs they will soon go slack again and can break under normal working loads.

Just a thought, other than the car being on a level surface when the brace is re-installed is there any other procedure requred, like order of tightening or a jigging tool? I'm assuming not but you never know with BMW.
 
From the TIS.

SI 410106288
Vehicles manufactured until May 2006 (using old bracket shape) installed. Identified with an M10 nut bolt welded into holder: 41Nm (30ft/lbs)
Vehicles manufactured after May 2006 (using new bracket type) installed. Identified with nut welded on bottom. Install new M10 screw: 56Nm (41ft/lbs) plus 105degrees +- 15 degrees of rotation.
Screws must NOT be reused.

These are in the Special Instructions (SI) portion of the TIS.
 
Shipkiller said:
From the TIS.

SI 410106288
Vehicles manufactured until May 2006 (using old bracket shape) installed. Identified with an M10 nut bolt welded into holder: 41Nm (30ft/lbs)
Vehicles manufactured after May 2006 (using new bracket type) installed. Identified with nut welded on bottom. Install new M10 screw: 56Nm (41ft/lbs) plus 105degrees +- 15 degrees of rotation.
Screws must NOT be reused.

These are in the Special Instructions (SI) portion of the TIS.
Click to expand...

Thanks again, I'll speak with the dealers to make sure I get the right parts
 
I was going to sell my car because of this awful noise!

By what I now know to be an unfortunate coincidence, this noise started after my ultra-trusted BMW specialist had fitted an iPod kit to my car. I now know that it was absolutely nothing to do with this work. Months of annoyance, causing me to distrust what has been a faultless garage for fifteen years, has been cured in about 10 seconds' of work with my socket set! Torquing four strut brace bolts was the answer. 100% I am astounded that such an annoying problem has such a simple solution. I now trust again my "perfect" garage.

I have already owned my Z4 for 3 1/2 years - at least a year longer than any other car I have ever owned before - It just does what I want a car to do! That intolerable bloody thumping noise was going to make me sell it! I was quite upset, because out of six other BMWs, four Porsches, four MGs and lots of others, it is my nearest to a perdect car that I have ever owned. It is now, once again, the car that I cannot see any replacement for!

Boxster envy? I have none!

For the Z4 Forum: my eternal gratitude!

A
 
Did mine too
Bolts were £.90 each and I notice they are 16 mm a slightly unusual size no doubt to reduce the temptation to " have a go"

Fixed the cracking noise of course
 
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