Suspension clunk driver side

[rorz12]

So I've had this problem since I got the car and for the life of me I just can't figure out what's causing it and hoping somebody here has had the problem before and managed to fix it!

Basically, when driving over a speed bump especially a sharp/harsh one, you can feel a clunk through the driver footwell that almost feels like your suspension strut is shot, like something heavy and metallic is loose. It doesn't happen on the passenger side at all which feels normal and solid as it should.

I already replaced the entire front suspension when I bought the car (lower and upper control arms, tie rods, spring struts and mounts, swaybar links and bushings), checked that everything is torqued to spec including the steering rack, so I'm really out of ideas..

Help

[suj999]

I remember had something like this on the last F10.
I too replaced everything didn't fully solved it the next thing I was going to replace the bushings on the front anti roll bar

[scubachris]

hi.
i dont know about the f06 grand coupe but the f13 coupe has the front sway bar (anti roll bar) bushes bonded onto the sway bar itself..you cant buy the bushes seperately and you would literally have to cut the old d bushes off.
if you have changed the shocker,spring,top mount.top and bottom wishbones.and the most likely bottom ball joint then it could be the suspension compressing and banging into the chassis somewhere? have you cheched for tell tale rub marks? sway bar drop links make more noise over an uneven road more than speed bumps.
i had a similar noise on my first f13 but it was the damper rod snapped off inside the shocker.
can you get it on a ramp,pull the underneath bash plate off and get someone to bounce the car on its suspension by pulling on the sway bar and someone else listening?thats what i did.
it does sound like a suspension part that compresses more over a sharp speed bump than an uneven road..has the shocker lost fluid and banging on the bump stop ?

[scubachris]

could it be the exhaust banging under the floor pan?

[rorz12]

Originally Posted by suj999

I remember had something like this on the last F10.
I too replaced everything didn't fully solved it the next thing I was going to replace the bushings on the front anti roll bar

Originally Posted by scubachris

hi.
i dont know about the f06 grand coupe but the f13 coupe has the front sway bar (anti roll bar) bushes bonded onto the sway bar itself..you cant buy the bushes seperately and you would literally have to cut the old d bushes off.
if you have changed the shocker,spring,top mount.top and bottom wishbones.and the most likely bottom ball joint then it could be the suspension compressing and banging into the chassis somewhere? have you cheched for tell tale rub marks? sway bar drop links make more noise over an uneven road more than speed bumps.
i had a similar noise on my first f13 but it was the damper rod snapped off inside the shocker.
can you get it on a ramp,pull the underneath bash plate off and get someone to bounce the car on its suspension by pulling on the sway bar and someone else listening?thats what i did.
it does sound like a suspension part that compresses more over a sharp speed bump than an uneven road..has the shocker lost fluid and banging on the bump stop ?

Originally Posted by scubachris

could it be the exhaust banging under the floor pan?

I already replaced the bushings on the sway bar (anti roll bar) when I overhauled the front suspension. BMW don't sell them but some aftermarket/OEM suppliers sell them and I managed to get good quality ones. The old ones actually slide right off, no cutting necessary.

It's interesting to read that some of you have faced a similar problem and I'm not going crazy. I have already done the bounce test multiple times and checked the suspension several times, it all checked out fine, which didn't surprise me as it's pretty new (10k miles old).

This morning I was paying more attention and noticed if I drive my right wheel or left wheel individually through a pot hole or bump, the clunk is negligible or absent and the suspension feels/sounds solid like it should. It's only when I go with both wheels over the bump that the clunk is felt.

[scubachris]

the reason bmw dont sell or list the front sway bar bushes is because they are not a seperate item..they are bonded onto the sway bar at the factory.
the fact you just slid the old ones off with no cutting would suggest that someone before you had cut the old factory bushes off and put aftermarket bushes on like you have,
this would also suggest to me that the last owner had the same issue you have now.
if you have also replaced the sway bar drop links then you can rule sway bar system out...incidentally the front sway bar drop links have a slight bend at one end and straight on the other end..it might be that one or both of yours might be the wrong way round and catching on something?

[rorz12]

Originally Posted by scubachris

the reason bmw dont sell or list the front sway bar bushes is because they are not a seperate item..they are bonded onto the sway bar at the factory.
the fact you just slid the old ones off with no cutting would suggest that someone before you had cut the old factory bushes off and put aftermarket bushes on like you have,
this would also suggest to me that the last owner had the same issue you have now.
if you have also replaced the sway bar drop links then you can rule sway bar system out...incidentally the front sway bar drop links have a slight bend at one end and straight on the other end..it might be that one or both of yours might be the wrong way round and catching on something?

I'm aware that they sell them only with the swaybar which is very strange.. every car I've owned sells them separately. Not sure what is special about BMW's swaybar (at least the standard one with no EDC or Active Anti-roll bar).

The one's I removed still had the BMW logo on them, so they were factory. I assume that even if they are bonded at factory, the bond wont last as soon as you start driving the movement of the bar against the fixed bushes over time and external temperatures will break that bond. It's probably there just for ease of installation.

Yes, at time of overhaul I replaced the swaybar links with Meyle HD links, which are supposed to exceed OE spec. Not sure if I got the original Lemforder if it would make a difference.. ? Still not sure whether the sound can be something else, like steering column related?

[thebmw]

I have a clunk with my 650 and 335 on the driver side. Suspension checks out by the mechanic. Have no idea what is causing it. Has not occurred in the 4 other 6 series and 3 other 3 series I have owned.

[rorz12]

Originally Posted by thebmw

I have a clunk with my 650 and 335 on the driver side. Suspension checks out by the mechanic. Have no idea what is causing it. Has not occurred in the 4 other 6 series and 3 other 3 series I have owned.

That's a lota 6 series you've owned.. So you can confirm that in the passenger side you don't feel the clunk through the footwell and in the driver's side you do? That's exactly my problem..

The only other mechanical thing I can think of that's heavy on the driver's side but not present on the passenger side is the steering column assembly and the steering rack and pinion. But I don't have any problems with my steering. Also I don't recall feeling anything through the steering wheel, it's mostly felt through the footwell.

[thebmw]

Originally Posted by rorz12

That's a lota 6 series you've owned.. So you can confirm that in the passenger side you don't feel the clunk through the footwell and in the driver's side you do? That's exactly my problem..

The only other mechanical thing I can think of that's heavy on the driver's side but not present on the passenger side is the steering column assembly and the steering rack and pinion. But I don't have any problems with my steering. Also I don't recall feeling anything through the steering wheel, it's mostly felt through the footwell.

I love the F06/F13 platform, inside and out. I'm always looking to add more, but they have to be the right build.

Maybe the clunk is coming from the steering assembly, even though my steering is fine too. Maybe there is a bearing or bolt that is ever so slightly worn, causing the clunk when it is immediately stressed by a low speed bump. But trying to find that bolt/bearing may be a costly endeavor and may be variable between cars. It is interesting though that I have noticed it inconsistently across different platforms.

Not to go off topic, I will be at Doha airport 12 hours soon! Won't have time to see the country though, but I heard the airport is like a 5 star hotel.

[suj999]

The lower U joint on the steering wheel can make a small clicking noise, though this will be felt on the steering wheel and not through the seats.

part 32306790490

the noise too is often small but the feeling of slightly loose steering will often be together at very low speed.

[rorz12]

Originally Posted by thebmw

I love the F06/F13 platform, inside and out. I'm always looking to add more, but they have to be the right build.

Maybe the clunk is coming from the steering assembly, even though my steering is fine too. Maybe there is a bearing or bolt that is ever so slightly worn, causing the clunk when it is immediately stressed by a low speed bump. But trying to find that bolt/bearing may be a costly endeavor and may be variable between cars. It is interesting though that I have noticed it inconsistently across different platforms.

Not to go off topic, I will be at Doha airport 12 hours soon! Won't have time to see the country though, but I heard the airport is like a 5 star hotel.

The airport is quite nice! Which I assume by now you have experienced.. I've never only transmitted through it so not sure what that's like.

Yeah the mystery with this clunk continues. I mean the biggest clue is that it doesn't happen on the passenger side, but still don't know how to translate that into figuring out the issue.

[rorz12]

Originally Posted by suj999

The lower U joint on the steering wheel can make a small clicking noise, though this will be felt on the steering wheel and not through the seats.

part 32306790490

the noise too is often small but the feeling of slightly loose steering will often be together at very low speed.

I used to have the small clicking in the steering wheel and when I got a new steering column U-joint it didn't resolve it. Later, I changed the active steering motor and sensor on the steering rack and it resolved it. Actually I have an open post on this somewhere, I should update it..