[Tymestream]

Hey everyone! I have been a long time BMW owner and have been around the forums over the years but not too active. I do have a question that would benefit from the experiences of others though:

A few months ago I noticed (like the title suggests) a rattling from the front end over uneven roads or broken pavement. I have had multiple BMW's in the past and always attributed this to control arms or other linkages. Both my local garage and the local BMW dealer suggest that it is the front struts, but other than the noise, there are no typical strut related problems like loose or bouncy front end also there is no leakage. Both shops suggest that everything else in the front end is sound and tight. I understand this may sound pretentious, and it's not that I don't believe the shops - it's just that they both admitted to "guessing" what it might be since it is not a directly visible problem.

I can't reconcile the fact that the sound is SO much like failing control arms with the fact that there does not seem to be any other strut related problems? I will post a video very soon for sound reference, but I have been postponing this issue and am eager to here any experiences anyone may have with this type of noise/issue.

Driving over 30km/h the sound disappears, perhaps masked by other road/engine noises and larger bumps like speed bumps do not create the noise. But at speeds under that over bumpy, uneven surface that sound is pronounced and sounds more like wood banging against wood rapidly in time with the bumps rather than the harsh sound of metal on metal. (Video will clarify) There do not seem to be any other problems, car drives and handles great.

Thanks for any insight you may have! I'll get the video up as soon as I can.

2014 435xi
70000km
Adaptive M Suspension
M Sport Model

[M2Rush]

Originally Posted by Tymestream

H
M Sport Model

Welcome to the forum!

Around that mileage, they're probably blown as mine were. You can check if they're leaking by shining a light into your fender gap and look at the strut under the spring, if it's leaking then you have a blown strut and will need to replace to fix. The infamous steering wheel knock can produce a similar sound to a blown strut as well. Maybe it's time for coils if you've been thinking.

[sukhparm.7]

i had the exact same issue with my 15 335 with only 40k km on it. It was also more noticeable on colder days.
Was the struts. Fixed under warranty for me.

[BMWMTLQC]

Originally Posted by sukhparm.7

i had the exact same issue with my 15 335 with only 40k km on it. It was also more noticeable on colder days.
Was the struts. Fixed under warranty for me.

Had the same issue as well at 44 000km

[n00b17]

over time struts develop a dead spot and will start to rattle at certain speed and bumps, beside that there won't be any symptoms of a bad strut.

[mark_tdot]

Originally Posted by BMWMTLQC

Had the same issue as well at 44 000km

Same thing for me as well.

Happened at around 59k and was covered under warranty.

Here is a copy and paste from the dealer invoice:

1 31-12-6-854-723 TENSION STRUT WITH WARRANTY
1 31-12-6-854-724 TENSION STRUT WITH WARRANTY
2 33-30-6-787-062 COMBINATION NUT WARRANTY
2 31-10-6-885-777 HEXAGON SCREW WITH WARRANTY
2 31-10-6-885-777 HEXAGON SCREW WITH WARRANTY
2 31-20-6-795-249 COLLARSCREWWITHSP WARRANTY
1 37-11-6-793-871 LEFT FRONT SPRING S WARRANTY

1 37-11-6-793-872 FRONT RIGHT SPRING WARRANTY
2 33-32-6-760-668 SELF-LOCKING COLLAR WARRANTY
2 31-30-6-798-530 HEXAGON SCREW WITH WARRANTY
2 07-11-9-905-032 HEX NUT WARRANTY

2 31-20-6-795-249 COLLAR SCREW WITH S WARRANTY
2 33-32-6-768-884 HEXAGON NUT WITH CO WARRANTY
2 33-30-6-787-062 COMBINATION NUT WARRANTY
6 31-30-6-863-134 HEX BOLT WITH WASHE WARRANTY

[Torontof32]

Check your top mount. There are bearings in it. It could be a possible cause for the noise.

[Tymestream]

Thanks for the replies guys! Been away for a while and am just getting to this. The struts are definitely worn and I am replacing with B8 Damptronic, problem is, I can't seem to find strut mounts for the Adaptive M suspension, all the parts say "for non Adaptive suspension".

The problem is all the "for adaptive suspension" mounts all have 5 bolt hole pattern. My car has a 3 bolt hole pattern. (All relevant mounts have an extra bolt hole for a brace in the engine bay but it is not actually mounting the strut.)

These are for correct car, looks identical to mine but say not for adaptive suspension:

https://www.autopartsway.ca/partlist.../pagenum1/tabs

This one is for my car (apparently), but have the 5 hole pattern which would not fit:

https://www.ecstuning.com/b-genuine-...h/31306881930/


Any experience with this issue? Thoughts?

Thanks again.

[Tymestream]

Update: Fortunately, I did not need strut bearings, the existing ones where in great shape. I just wanted to be ready in case.

I have now completed the entire car with Bilstein B8 with damptronic. Though I only had a problem with the front, I figured I'd do it all.

What a difference. In addition to solving my rattling problem, the car is so much more composed. It feels new. I forgot how big of a difference new suspension can make.

The shocks and struts were direct replacement for the F32 M Adaptive suspension and all settings work properly (Comfort, sport ect) The B6's are a solid upgrade from stock with only a minor hit to comfort - very minor and subtle, however, the effect on car dynamics is significant. I am very pleased.

Many of the resources; people and links, on the forum helped me immensely. Thanks!

[M2Rush]

Originally Posted by Tymestream

Update: Fortunately, I did not need strut bearings, the existing ones where in great shape. I just wanted to be ready in case.

I have now completed the entire car with Bilstein B8 with damptronic. Though I only had a problem with the front, I figured I'd do it all.

What a difference. In addition to solving my rattling problem, the car is so much more composed. It feels new. I forgot how big of a difference new suspension can make.

The shocks and struts were direct replacement for the F32 M Adaptive suspension and all settings work properly (Comfort, sport ect) The B6's are a solid upgrade from stock with only a minor hit to comfort - very minor and subtle, however, the effect on car dynamics is significant. I am very pleased.

Many of the resources; people and links, on the forum helped me immensely. Thanks!

Hey,
You mentioned both B6 and B8, which one did you end up going with? I assume B8? What was the price you paid if you don't mind sharing. Lastly, where did you get it? I was not able to locate the adaptive versions online in Toronto. I'm planing to replace as well.
Thank you!

[Tymestream]

Sorry for the typo. I actually went with the B6's. I feel these 435 are so wide and low I don't need any more. Just me personally.

I purchased through Marcor Automotive- Marcor.ca (You may get Northern Performance, which is their retail name) in Burlington. Price, including tax, was - hold your breath - $2900.00

They arrived at my door with 10 days and total shipping was only $60 bucks (that was included in the price)

The only glitch I had, and am still dealing with was that they sent the wrong EDC connectors for the back shocks and the orientation of the connectors make using the old ones impossible. When I wrote the post above I had only done the front and it worked perfect and made such a difference that I assumed the back would be just as smooth. Anyway, I talked to the guy I ordered them through and he spoke with Bilstein and they are on the way to me now.

Hope this helps.

[M2Rush]

Originally Posted by Tymestream

Sorry for the typo. I actually went with the B6's. I feel these 435 are so wide and low I don't need any more. Just me personally.

I purchased through Marcor Automotive- Marcor.ca (You may get Northern Performance, which is their retail name) in Burlington. Price, including tax, was - hold your breath - $2900.00

They arrived at my door with 10 days and total shipping was only $60 bucks (that was included in the price)

The only glitch I had, and am still dealing with was that they sent the wrong EDC connectors for the back shocks and the orientation of the connectors make using the old ones impossible. When I wrote the post above I had only done the front and it worked perfect and made such a difference that I assumed the back would be just as smooth. Anyway, I talked to the guy I ordered them through and he spoke with Bilstein and they are on the way to me now.

Hope this helps.

Oh no worries, the B6's are exactly what I was looking into as well! Sorry for the delayed response, I don't logon as much anymore... I appreciate the time you've taken to provide such detailed information! Wow that's quick, I guess they're not back ordered anymore, which is great news.
Definitely, this info is very helpful to me!
Thank you!

[mdchris]

I know this is an old thread, but I am on the hunt for a solution for mine. Did yours sound like you had a couple golf balls inside a cardboard box and were shaking it around? This is how mine sounds whenever it's below 0 and I drive slowly. It doesn't even matter if the ground is uneven, it happens even just driving across a clean paved parking lot. It drives me CRAZY and the dealer is telling me this is normal. They even let me drive another car in their parking lot and it did the same thing! Car is a 2013 335xi, m-adaptive suspension, has been doing this since about 45k km when I got the car.

I should note that while i'm on the hunt for a solution, i'm not on the hunt for a $3000 solution lol. I have an extended warranty so if it's bad struts they should be replaced for free.... But i'd have to convince the dealer that's what it is.

[Sarah-F]

F11 520D 2014 160K km

Diagnosis
1. Visual check suspension and mechanical stressed with crowbar. => no problem found
2. Listened to all relevant suspension parts with measuring microphones. Wishbones, steering rods, roll bar and connections, springs, strut tower on top. => no problem found
3. With measuring microphones listened to "upper radiator braces". => problem is in the area.
4. Disassembled upper radiator braces and listened to radiator cover plate. => problem still there
5. Top screw of front diagonal braces unscrewed => problem gone
6. Top screw of front diagonal braces screwed in again and tightened properly. => problem back.
7. Next step is to disassemble the bumper to tighten the bottom screws of the diagonal braces. 99% of the problem is there. Job is scheduled for 13 July, I'll keep you posted.

Hope this helps some of you.

[Mkesler75]

Just adding this as I couldn’t find my exact symptoms which did turn out to be the struts. 2015 335i F34 60k miles. Especially on cold mornings I would get a rattle on the front driver side at low speed and nearly any road imperfection. Sounded just like a bad or loose sway bar link. The difference is after a few miles it would go away. Checked the links and struts there was no visual damage or easy testing/verification that produced the noise. Installed new struts this weekend and noise is gone and boy they must have been bad. Just switched from a suv to sedan so I don’t think I realized how bad they were. I assume they would “charge” or pressure up as they were in use after sitting overnight and the symptom went away. I found so many posts on the steering bushing that I almost did that first. Anyway, thought this may be helpful for someone else trying to diagnose this noise.

[Oksamit78]

Originally Posted by Mkesler75

...Sounded just like a bad or loose sway bar link.

Have exactly that at the front on 2017 F34 with M-Adaptive struts. Car has 67K kms, but had it since I've got it with 32K 2 years ago. Will be installing lowering springs in early May. Will see if struts move from "dead" spot and improve. If not - strut replacement is next.

[asbrr]

Hm - seems I may have a similar issue. 2014 335i with 92K kms, front struts replaced under warranty at around 67K kms. Bizarre how poor the life on these is (assuming that's the problem I have). Need to check for leaks first, also curious if problem goes away when it's warmer.

[johnung]

Originally Posted by Mkesler75

Just adding this as I couldn’t find my exact symptoms which did turn out to be the struts. 2015 335i F34 60k miles. Especially on cold mornings I would get a rattle on the front driver side at low speed and nearly any road imperfection. Sounded just like a bad or loose sway bar link. The difference is after a few miles it would go away. Checked the links and struts there was no visual damage or easy testing/verification that produced the noise. Installed new struts this weekend and noise is gone and boy they must have been bad. Just switched from a suv to sedan so I don’t think I realized how bad they were. I assume they would “charge” or pressure up as they were in use after sitting overnight and the symptom went away. I found so many posts on the steering bushing that I almost did that first. Anyway, thought this may be helpful for someone else trying to diagnose this noise.

Glad to hear that replacing struts fixed your issue. The stock standard type struts/shocks are poor quality and could really be replaced at anytime. Koni Special Actives are the replacements that I would recommend.

The Adaptive struts/shocks are higher quality and seem to last anywhere between 45k-95k miles. When one of those goes bad, it tends to leak fluid. Adaptive/EDC are more expensive than conventional passive dampers. I’d suggest just replacing in pairs if one leaks. Bilstein B4-Damptronic are closest to stock ride. Bilstein B6-Damptronic are much stiffer and many have reportedly been dissatisfied with their harsh ride.

The stock front control arm bushings are often the culprits if there are steering or front noise issues. Those big cylindrical bushings are fluid filled and tend to leak to indicate that they are shot. See photos. Don’t attempt to replace just the bushing. It’s cheap and easy to replace the entire arm (always in pairs) so that you get a new bushing, aluminum arm and ball joint. About 1-2 shop hours for a pair and maybe 2-3 for both pairs of front control arms.

Hope this helps!

[johnung]

Originally Posted by Oksamit78

Have exactly that at the front on 2017 F34 with M-Adaptive struts. Car has 67K kms, but had it since I've got it with 32K 2 years ago. Will be installing lowering springs in early May. Will see if struts move from "dead" spot and improve. If not - strut replacement is next.

When installing lowering springs make sure to shorten your bump stops to prevent premature bottoming out which will reduce damper life. Trim top of bump stop with a serrated knife. I trim off about 1/2”-5/8” for a 1” estimated spring drop.

I recommend Eibach springs because they are less harsh and better sized for specific models. Also Bilstein B4-Damptronic for BMW Adaptive replacement. B4-D’s have recently been in short supply but seem to be more available now.

[Oksamit78]

Originally Posted by johnung

When installing lowering springs make sure to shorten your bump stops to prevent premature bottoming out which will reduce damper life. Trim top of bump stop with a serrated knife. I trim off about 1/2”-5/8” for a 1” estimated spring drop.

I recommend Eibach springs because they are less harsh and better sized for specific models. Also Bilstein B4-Damptronic for BMW Adaptive replacement. B4-D’s have recently been in short supply but seem to be more available now.

Yeap, the shortened bump stops are planned for.
The springs are Eibachs Pro Springs. I have good experience with those on my cars with moderate drops I like and without blowing stock shocks. I have had a set on for 200K kms now and still counting.

Bilsteins will be considered if I can't fix the rattle. Thanks!