Right rear "thunk" noise

[Kief]

Hey Guys,
I know I read someone posting about a "thunk" noise coming from the rear of the car when riding over bumps. It doesn't happen all the time, only on certain road imperfections. Mine sounds like it comes from the right rear tire/suspension area. I checked the trunk for any loose items (e.g., tow hook, tools) but I still get the noise. Perhaps it is the infamous '09 springs which need replacing?

[Vintage]

maybe, as all 4 struts on m wife's Z4 35i with adaptive suspension needed replacement

[Kief]

Originally Posted by VintageBMW

maybe, as all 4 struts on m wife's Z4 35i with adaptive suspension needed replacement

Yes, but James there is more to your story. BTW, any news?

[MilitaryE89]

i've had some offline convos with kief about my experiences with this as well...it sucks! first time it happened i freaked! cars in the garage for the winter but as soon as it thaws (germany) i will take it to the dealer...i think it should get warm here around august...sigh

[Kief]

Originally Posted by MilitaryE89

i've had some offline convos with kief about my experiences with this as well...it sucks! first time it happened i freaked! cars in the garage for the winter but as soon as it thaws (germany) i will take it to the dealer...i think it should get warm here around august...sigh

I plan to schedule something soon.
Yes, the noise was unusual at first, but now I know exactly when I'll hear the noise on my route to work/home. There are two specific road imperfections (unavoidable) that every time I ride over them I hear the noise.

[MilitaryE89]

what type of road imperfections cause this for you? As soon as the winter is over im taking mine in and don't want to be looked at all crazy when i can't replicate the sound. I also have what i assume is a related problem...my suspension creaks! sounds like and old jaguar x-type! don't know if it is audible from outside the vehicle, but it is noticable to me inside. Very faint...but unfortunately i have outstanding hearing and it drives me batshit! Again...have to wait til the spring thaw...sigh

[teagueAMX]

Originally Posted by Kief

I plan to schedule something soon.
Yes, the noise was unusual at first, but now I know exactly when I'll hear the noise on my route to work/home. There are two specific road imperfections (unavoidable) that every time I ride over them I hear the noise.

Originally Posted by MilitaryE89

what type of road imperfections cause this for you? As soon as the winter is over im taking mine in and don't want to be looked at all crazy when i can't replicate the sound. I also have what i assume is a related problem...my suspension creaks! sounds like and old jaguar x-type! don't know if it is audible from outside the vehicle, but it is noticable to me inside. Very faint...but unfortunately i have outstanding hearing and it drives me batshit! Again...have to wait til the spring thaw...sigh

Those sound more like external issues such as loose motor or transmission mounts, or a loose cross member, rather than an internal transmission sound. I'd be very concerned if my actual transmission made any kind of audible sound going over a bump or road imperfection.

[MilitaryE89]

no no...not transmission...suspension.

Originally Posted by teagueAMX

Those sound more like external issues such as loose motor or transmission mounts, or a loose cross member, rather than an internal transmission sound. I'd be very concerned if my actual transmission made any kind of audible sound going over a bump or road imperfection.

[teagueAMX]

Sorry, my bad. I did read that about the suspension sound, but there was another thread about a transmission sound, and. . .

[Kief]

Originally Posted by MilitaryE89

no no...not transmission...suspension.

+1
I was over on the previous Z4's subforum on the Fest and found similar issues. It seems those owners mentioned tightening the rear sway bar/mount and/or subframe bolts. Apparently, some cars had loose bolts!!!

It is difficult to describe the actual road imperfections. One area in particular: there was road work where they dug a trench and when finished covered the area with blacktop, but the area isn't level with the rest of the road. It sort of resembles a very low speed bump. The rear wheel well thunk noise occurs everytime I drive over it.

[MilitaryE89]

you got a link to that post kief?

[Kief]

Originally Posted by MilitaryE89

you got a link to that post kief?

http://www.bimmerfest.com/forums/sho...d.php?t=423723

[Vassilis008]

The car that I test drove had exactly the same problem with less than 2000 miles on the dash. The dealer told me it was because of a combination of the Adaptive M-Suspension, 19" runflats and bad road

[MilitaryE89]

stuffed scott? clarification please

[MilitaryE89]

any updates on this yet kief?

[zEdP]

Sounds familiar but I only hear it when I drive of my driveway slowly. I cannot hear it when driving on bad roads.

Perhaps it is the infamous '09 springs which need replacing?

What's wrong with the 09 springs? No fuel pump disaster

[MilitaryE89]

im just worried they bit off more than they could chew with this car suspension wise...at least with mine. the "thunking" is the least of my worries, yet a big one...im most worried about the squeaking it makes. mine was one of the first american spec models to roll off the line so i guess that is to be expected

[Kief]

Originally Posted by MilitaryE89

any updates on this yet kief?

It's going in next week (20th). With over 4 feet of snow within the last week, I haven't gotten out much!

[rmorin49]

Originally Posted by Kief

It's going in next week (20th). With over 4 feet of snow within the last week, I haven't gotten out much!

Any update? Sun is finally out and our snow is almost gone.

[Kief]

Originally Posted by rmorin49

Any update? Sun is finally out and our snow is almost gone.

I took it in a few weeks ago, but to no avail, the "thunk" is still evident.

The lead tech and I went out together before I dropped it off. I could barely replicate the noise. Perhaps it isn't a major problem since it doesn't occur everytime, but the "thunk" doesn't sound right.

According to the invoice, they tightened/checked all mounting bolts, subframe, etc.--everything was tight. Checked convertible top--tight. They lubricated all contact points of the top (and managed to get lubricant all over the place and I think a new swirl mark on my trunk). Don't get me wrong, I'm always treated very well at my dealer and have a great rapport with the serivce folks, but sometimes it's just not worth the effort. They want me to bring it back, but I'm not sure. Maybe I'll have them look again when I get my winter shoes swapped.

[rmorin49]

Originally Posted by Kief

I took it in a few weeks ago, but to no avail, the "thunk" is still evident.

The lead tech and I went out together before I dropped it off. I could barely replicate the noise. Perhaps it isn't a major problem since it doesn't occur everytime, but the "thunk" doesn't sound right.

According to the invoice, they tightened/checked all mounting bolts, subframe, etc.--everything was tight. Checked convertible top--tight. They lubricated all contact points of the top (and managed to get lubricant all over the place and I think a new swirl mark on my trunk). Don't get me wrong, I'm always treated very well at my dealer and have a great rapport with the serivce folks, but sometimes it's just not worth the effort. They want me to bring it back, but I'm not sure. Maybe I'll have them look again when I get my winter shoes swapped.

It does sound like it must be a suspension issue. It's not a loose wheel, is it?

[Kief]

Originally Posted by rmorin49

It does sound like it must be a suspension issue. It's not a loose wheel, is it?

No, I always double-check my wheel bolts after a dealer years ago decided only to tighten 4 bolts!