Center dash windshield creaking noise

[ANILE8]

If anyone could help I would be most gratefull.

I get this God awful creaking noise that sounds like the windshield is flexing in the middle at the bottom, (although I know it is not) when I drive over a rough surface or up or down my driveway and the body flexes.

I have spent so much time on this I am just about getting depression from it and the enjoyment of driving is severely compromised because if it.

This has been driving me nuts for weeks.

When I searched the web concerning this problem, all you hear is to tighten the strut braces. This is not my issue, they are already wheel nut tight!

What DOES fix the problem is when I remove the strut braces entirely!

So this would tell me the problem has something to do with the strut braces, obviously. Or more accurately that they are transmitting the sound or force to the firewall.

I have also inspected the strut brace mount points and checked for hairline cracks which there are none.

I have checked in no particular order already.

• Engine mounts
• Strut brace mounts (no cracks)
• Removed Engine bay cowling to check for damage
• Front coilovers
• Drop links
• Front brake assembly bolts
• Strut tower bolts
• Windshield wiper motor assembly bolts
• Windshield wiper bolts
• Steering rack
• Subframe front bolts
• Subframe front brace bolts

[Clearancediver]

Have you re-torqued the strut brace bolts ..... as well as inspecting.

[XMetal]

When people say "tighten the strut braces", they're telling you to do it on the firewall nuts/bolts (whichever version you have), not those on the strut towers. Is that what you did (tighten the brace nuts/bolts at the firewall)?

[chickdr]

Maybe buy a new set of nuts/bolts and try that? It has to be the braces. I had that issue very early on in mine. I simply tightened the nuts and it has never resurfaced.

[3002 tii]

Originally Posted by chickdr

Maybe buy a new set of nuts/bolts and try that? It has to be the braces. I had that issue very early on in mine. I simply tightened the nuts and it has never resurfaced.

Or maybe even some blue loctite?

[ANILE8]

Originally Posted by Clearancediver

Have you re-torqued the strut brace bolts ..... as well as inspecting.

Yes, they are wheel nut tight as specified in my OP.

Originally Posted by XMetal

When people say "tighten the strut braces", they're telling you to do it on the firewall nuts/bolts (whichever version you have), not those on the strut towers. Is that what you did (tighten the brace nuts/bolts at the firewall)?

Yes, I tightened all four strut brace nuts. Two on the firewall and the two on the strut towers.

Originally Posted by chickdr

Maybe buy a new set of nuts/bolts and try that? It has to be the braces. I had that issue very early on in mine. I simply tightened the nuts and it has never resurfaced.

It did buy a new set of nuts thinking something was wrong with them because I am getting so desperate now to fix this. Sadly this did not fix the problem.

I got out of bed at 0530hrs this morning to my wife's surprise and pulled off my FCAB to check if they could be causing the noise as they are the monoball type. I greased them and put them back and when for a drive and the noise is still there.

How can such a simple problem really be so hard to find?

[WAMz4]

How about the struts themselves? I've never seen it happen but it makes sense that sound is being transferred through the strut brace. The problem is from where? Maybe a leaky/squeaking strut or cracked/broken coil over spring? If money were no object you could just start replacing parts until you eliminate the problem.
Good luck finding it.

[wdb]

A surefire way to eliminate the strut braces as the source would be to remove them and go for a (short, easy) drive.

[thrak410]

Do you guys even read the posts??

[ANILE8]

Ok, I am 99% sure I know what it is.

I don't know why it has taken me this long to believe it but here goes...

I got my front windshield replaced late last year. It was an aftermarket windshield but I am super happy with the visual quality and if not for this noise problem I would have thought no more about it. I did call my local BMW dealer and they checked on their system and told me that there was no OEM stock even in Germany. So that being the case, I figured that this would be perfectly fine.

However, the very next day when my wife and I went for a drive we could hear this terrible creaking noise coming from the center bottom part of the windshield.

I called the local shop and told them about this problem and thought that the windshield was loose and that the urethane seal had been compromised.

I spoke to the manager and he explained to me that this was virtually impossible as when it dries it is chemically welded to the chassis.

The installer told me that I could drive the vehicle about one hour after the install but I waited for a full 24hrs as I didn't need to go out again that day and it was fairly warm so I am positive that it had ample time to fully cure.

Hence, why I have been tearing my vehicle apart for the last month checking every nut and bolt as I thought it might have been a crazy coincidence and I didn't want to look stupid accusing them of something that wasn't their fault!

Anyway, I am going to drive back to their head office tomorrow and request that the manager come for a test drive with me to experience this problem as you can actually quite easily hear that it is the sound of glass on metal almost making a clanging noise when you hit a bump.

If they do not agree to refit the windshield there is going to be a huge shit fight between myself this windscreen company and my insurance company as they paid for the new windshield to be replaced.

All I know is that the noise was not there before they touched my vehicle and replaced the windshield and then the very next time I drive it I have this huge problem with a noise coming from the windshield.

The problem remains that if this company does replace the windshield and the problem is still there it will be an endless argument over if they installed it correctly the second time as I am sure they will say that this proves that it was not the windshield and I will say they did it incorrectly again.

Any advice on the best way to handle this problem?

[Huz-Z]

Having worked in a windshield shop years ago, it sounds like the windshield edge is scrubbing against a hard surface, like the stops at the bottom edge of the windshield. The stops are typically placed on the bottom edge of the windshield frame to prevent it from sliding out of place in a collision. Under no circumstances should the glass be touching the stops or any other hard surface. If the glass is touching somewhere along an edge, then that is the source of the noise and would absolutely be an incorrect installation. The shop should re do the install with new glass at no cost to you. I would not accept reinstalling the same glass. That’s because it has to be sawed out with piano wire, and that can splinter the edge, meaning it could crack months after being reinstalled.

[Huz-Z]

Ask a competing glass shop to take a look. I’m sure they will be more than happy to point out a competitor’s bad work.

[wdb]

Originally Posted by thrak410

Do you guys even read the posts??

Apparently only so far and then I get bored?

Apologies to those who may have been offended. Glad the OP is on track to resolution.

[ANILE8]

Originally Posted by Huz-Z

Having worked in a windshield shop years ago, it sounds like the windshield edge is scrubbing against a hard surface, like the stops at the bottom edge of the windshield. The stops are typically placed on the bottom edge of the windshield frame to prevent it from sliding out of place in a collision. Under no circumstances should the glass be touching the stops or any other hard surface. If the glass is touching somewhere along an edge, then that is the source of the noise and would absolutely be an incorrect installation. The shop should re do the install with new glass at no cost to you. I would not accept reinstalling the same glass. That’s because it has to be sawed out with piano wire, and that can splinter the edge, meaning it could crack months after being reinstalled.

Someone with first-hand industry experience, how lucky am I

This is quite a weird circumstance in so much that I was watching the installer put the new windshield in, in my garage, as they install on-site. This is quite normal in my area.

I believed that the bottom edge might have been sitting too close to the frame, so I took off the cowling to inspect. It looks ok to me but then again I wouldn't really know.

I cannot see the windshield touching the frame as there is about a 5mm gap and the urethane is rock hard now. Please see images below...

There do not appear to be any 'stops' or anything, as you were talking about. Does this look normal to you?

The windshield does not flex anywhere when you press down on it.

I don't know about the sides or top yet.

I watched the install put a thick bead of black urethane (about the thickness of your middle finger) right around the frame and then just slide the windshield in. The cowling was not removed and there were no blocks or anything used for spacing. the windshield was just pressed in then some painters tape placed down from the roof onto the windshield to hold it in place while it cured.

[racerbruce]

Wowie - so great that you connected the dots regarding the recent windshield replacement and that Huz-Z has provided professional insight. I agree with the recommendation to have another auto glass service provider assess and offer comment.

Perhaps your insurance agent will back you up and regardless of the decision of the current auto glass company that installed the windshield incorrectly, and allow you to have another auto glass company install the replacement windshield.

If the company that installed it wrong is allowed to touch your car again, there's just too much risk and history of poor processes.

[racerbruce]

Any updates on the windshield replacement??

[ANILE8]

From the great advice I have received by other members, this week I have taken my vehicle to be inspected by two separate windshield companies to get their opinion on this problem.

Both competitors could not fault the installation. The gaps looked perfect to them and in no area was the windshield even close to touching the frame.

I then returned to the company that installed it and we had a chat then I took the manager for a test drive. I explained that when I remove the strut braces that the noise disappeared and the noise was not present before the windshield replacement.

We loosened the strut brace around the firewall and installed some rubber washers. This completely resolved my problem with the noise. Everything I have read about this problem concerning the strut braces recommends tightening the nuts. However, the tighter I did the nuts the worst the noise became.

So the question still remains as to why was it ok before the installation then different after, as I never had this problem. The installer could only speculate that when the windshield is removed that the chassis can slightly move as it is a structural component of the vehicle. Also, because my suspension is so stiff, this would exacerbate the problem which might not even be noticeable on factory suspension.

Anyway, whatever happened I am fine with this workaround as long as it fixes the problem. Thanks to everyone that has tried to help.

[racerbruce]

Wowie!
What a story - what a chase!

So glad you have resolved this.

[XMetal]

So...what you are saying is that you're adding dampers to the chassis while everyone else is going for solid bushings everything?

BTW - great detective work!

[yousefnjr]

Originally Posted by ANILE8

...

When I searched the web concerning this problem, all you hear is to tighten the strut braces. This is not my issue, they are already wheel nut tight!

...

I think that may be your problem. Per TIS if your strut is held on by nuts, then it should be 41 nm (about 30 ft-lbs)




You also might want to check the mounting points for any cracks, there's an old service bulletin (below) where the issue description sounds a lot like yours

[racerbruce]

Way to go yousefnjr - this is info not provided to-date; perhaps this could be important to someone out there; it appears BMW corrected it in Oct 2006; my build date is 17 Nov 2006 but I will keep this info to check for this.

[ANILE8]

I did actually see this information about cracking strut mounts in another post and it was the first thing I checked. Please re-read post #1.

I also checked the firewall end when I removed the cowling, inspecting carefully the welds and sheet metal. Everything looked ok.

I did always have my strut bars torqued to about 42ft-lbs and there was never a problem before. So why it suddenly became a problem after I had a new windshield fitted I guess will be an X-File that I will never know the answer to.