[LivNLearn]

Hello All,

Last month I bought a one owner 2016 M235i convertible with 62k miles on it. I noticed a vibration that starts at about 40MPH then decreases over 60MPH. Also hearing noise from the right front of the car when going over any road imperfections at all. Sounds like a bad sway bar link.

Took it back to the dealership that I bought it from and they said the front end is tight, the left front wheel is bent. Said they had a company that straightens them. Waited two weeks for the appointment and they had the car for a week to straighten the wheel and replace the heating element in the driver's seat base.

Got the car back and the heated seat works great but the vibration and noise are still there. Read a bunch on here and went out to my garage with the car shut off and when I move the steering wheel back and forth I hear clank, clank, clank, clank as clear as can be coming from the passenger side of the car. Apparently they didn't test drive the car or they would've noticed the vibration and noise.

Thinking it may be the steering rack bushing I called back to see about getting it back in the shop. Told them what I'd read and they said they thought the repair would take more than a day so now i have to wait two weeks for them to have a loaner available.

As a result I have a few questions at this point:

1. Does the M235i steering rack use the bushing toward the passenger side like some of the other series do?

2. Does clanking when moving the steering wheel typically end up being a bad bushing or steering rack if it doesn't use it?

3. Are there any known issues with this model that would cause the vibration?

4. Are the BMW dealerships typically pretty good or are they typically sloppy. I used to ride Harleys and learned that I could usually fix my Harley much better than they could so wondering if this is the same.

I was a mechanic in a past life so if it weren't so cold I'd jack the car up and look to see if it has the bushing or not and fix it myself if it has it.

The only benefit to this is they put me in brand new loaners. I had a new 230i X-Drive loaner for a week in the ice and snow while my car sat safely in their parking lot.

[Jaynen]

I get vibration when the car is cold which I assumed is the transfer case but then goes away

[freakystyly]

Not experienced with AWD but I'd be looking for a second opinion. Maybe look for an independent mechanic that has experience with BMWs and their AWD systems. The mechanics at the dealer are sometimes hit and miss.

Sounds like you've narrowed it down to a corner, that's not easy. Is the vibration dependent on road surface? or consistently just rotational speed of the wheels? I wonder if if the tie rod end is loose causing the clanking... Hows alignment? Does the car at least drive straight?

[M3SQRD]

If it happens when you turn the steering wheel, it could be the strut top mount bearing going bad. However, this would not create a vibration at different road speeds. Is there any play in the front wheel? A wheel bearing going bad could create a vibration at variable road speeds. Same thing with other suspension bushings. It would be easy to check for axial play in suspension components if it wasn’t cold out. The steering rack doesn’t use any bushings that you’d see from looking underneath the car.

[LivNLearn]

Originally Posted by freakystyly

Not experienced with AWD but I'd be looking for a second opinion. Maybe look for an independent mechanic that has experience with BMWs and their AWD systems. The mechanics at the dealer are sometimes hit and miss.

Sounds like you've narrowed it down to a corner, that's not easy. Is the vibration dependent on road surface? or consistently just rotational speed of the wheels? I wonder if if the tie rod end is loose causing the clanking... Hows alignment? Does the car at least drive straight?

The dealer aligned the car and the issue is still there. They say the front end is tight but I'm not sure I believe that. I'm going to get it up on a lift and check it our myself soon. The car handles great and goes straight down the road if you take your hands off the wheel. I've also replaced the tires and wheels and no change.

[LivNLearn]

Originally Posted by M3SQRD

If it happens when you turn the steering wheel, it could be the strut top mount bearing going bad. However, this would not create a vibration at different road speeds. Is there any play in the front wheel? A wheel bearing going bad could create a vibration at variable road speeds. Same thing with other suspension bushings. It would be easy to check for axial play in suspension components if it wasn’t cold out. The steering rack doesn’t use any bushings that you’d see from looking underneath the car.

The dealer says the front end is tight. They also said this before I showed them that the steering rack was bad though. Easy to prove with the clanking the car did turning the wheel left to right with the engine off. They replaced the rack under warranty and aligned it and it still has the vibration.

[M3SQRD]

Originally Posted by LivNLearn

The dealer says the front end is tight. They also said this before I showed them that the steering rack was bad though. Easy to prove with the clanking the car did turning the wheel left to right with the engine off. They replaced the rack under warranty and aligned it and it still has the vibration.

Have someone listen closely to the left and right strut top mounts on the strut towers as you turn the wheel to the left and right (or you listen while someone turns the wheel). The upper bearing in the strut top mounts can go bad regardless of whether everything is tight. Depending on how badly it’s damaged, it could potentially create a vibration.

Where do you feel the vibration the most; e.g., steering wheel, throttle/brake pedal, the seat, etc.?

[LivNLearn]

Originally Posted by M3SQRD

Have someone listen closely to the left and right strut top mounts on the strut towers as you turn the wheel to the left and right (or you listen while someone turns the wheel). The upper bearing in the strut top mounts can go bad regardless of whether everything is tight. Depending on how badly it’s damaged, it could potentially create a vibration.

Where do you feel the vibration the most; e.g., steering wheel, throttle/brake pedal, the seat, etc.?

I'll get someone to assist and listen and see what I hear. It's felt mostly in the throttle pedal and the seat.

[LivNLearn]

Originally Posted by M3SQRD

Have someone listen closely to the left and right strut top mounts on the strut towers as you turn the wheel to the left and right (or you listen while someone turns the wheel). The upper bearing in the strut top mounts can go bad regardless of whether everything is tight. Depending on how badly it’s damaged, it could potentially create a vibration.

Where do you feel the vibration the most; e.g., steering wheel, throttle/brake pedal, the seat, etc.?

I just jacked the car up on each side and using a pry bar under the tire am able to get 1/2 to 1 inch of vertical movement of the tire/wheel/strut assembly. I can actually see the entire strut moving up and down with a light clunk at each end of travel. It appears that the strut mounts are wasted.

[M3SQRD]

Originally Posted by LivNLearn

I just jacked the car up on each side and using a pry bar under the tire am able to get 1/2 to 1 inch of vertical movement of the tire/wheel/strut assembly. I can actually see the entire strut moving up and down with a light clunk at each end of travel. It appears that the strut mounts are wasted.

I’m trying to visualize what you’re doing…are you compressing the spring and damper piston when you’re prying or is the spring/piston not compressing and moving the same amount as the strut body? The strut top mount bearing design isn’t the best.

However, it’s a good time to replace the oem top mounts with a set of street camber plates. Vorshlag, Ground Control and Millway make camber plates that work with stock springs. If you’re not tracking your car, Millway makes a street version that should not increase NVH at all, allow you to properly align front camber (same value left and right or increase it to something reasonable around -2.5 deg), and eliminate a common issue.

[LivNLearn]

Originally Posted by M3SQRD

Have someone listen closely to the left and right strut top mounts on the strut towers as you turn the wheel to the left and right (or you listen while someone turns the wheel). The upper bearing in the strut top mounts can go bad regardless of whether everything is tight. Depending on how badly it’s damaged, it could potentially create a vibration.

Where do you feel the vibration the most; e.g., steering wheel, throttle/brake pedal, the seat, etc.?

I jacked it up again and pulled the boot so I could see the strut rod. There's an inch of play in the actual strut before it starts doing any dampening. I suppose it's the struts actually, not the mounts.

[M3SQRD]

Originally Posted by LivNLearn

I jacked it up again and pulled the boot so I could see the strut rod. There's an inch of play in the actual strut before it starts doing any dampening. I suppose it's the struts actually, not the mounts.

The spring should be in compression when the suspension is at full drop. This means the spring and damper should move together without any play/relative movement (one develops force proportional to displacement, the other develops force proportional to velocity but they move together). What you’re describing sounds more like a main spring with zero preload on it. Stock front strut spring has a decent amount of preload. Can you take pictures or a video showing the motion?

[LivNLearn]

Originally Posted by M3SQRD

I’m trying to visualize what you’re doing…are you compressing the spring and damper piston when you’re prying or is the spring/piston not compressing and moving the same amount as the strut body? The strut top mount bearing design isn’t the best.

However, it’s a good time to replace the oem top mounts with a set of street camber plates. Vorshlag, Ground Control and Millway make camber plates that work with stock springs. If you’re not tracking your car, Millway makes a street version that should not increase NVH at all, allow you to properly align front camber (same value left and right or increase it to something reasonable around -2.5 deg), and eliminate a common issue.

I'm compressing the spring/piston when prying upward. There's an inch of play before it meets any resistance and contact noise when the compression begins and ends at the end of travel each way.

I just replaced the struts on a friend's Prius that had the same symptoms and all noise is gone now that they're were swapped out.

Agreed on swapping out the mounts when I do the struts assuming that these adaptive struts aren't supposed to do this. I can't imagine they would but am not 100% sure.

[LivNLearn]

Originally Posted by M3SQRD

The spring should be in compression when the suspension is at full drop. This means the spring and damper should move together without any play/relative movement (one develops force proportional to displacement, the other develops force proportional to velocity but they move together). What you’re describing sounds more like a main spring with zero preload on it. Stock front strut spring has a decent amount of preload. Can you take pictures or a video showing the motion?

I'll see if I can get a video. Thanks for helping out here.

[LivNLearn]

Originally Posted by M3SQRD

The spring should be in compression when the suspension is at full drop. This means the spring and damper should move together without any play/relative movement (one develops force proportional to displacement, the other develops force proportional to velocity but they move together). What you’re describing sounds more like a main spring with zero preload on it. Stock front strut spring has a decent amount of preload. Can you take pictures or a video showing the motion?

Here's a picture, couldn't upload the video. The strut is actually compressing very easily for an inch or so between the green lines that I added to the picture. It's like there's no preload. Is this just a worn out strut or does the adaptive strut have this much "play"? I've never seen one with this much play before dampening occurs and I've checked a fair amount of them out. Was a mechanic in a previous life. If it were off of the car and you stood it upright I think you'd be able to easily depress the piston by hand an inch or so. With these being electronically controlled do they have the same preload that a gas-charged strut would have?

[M3SQRD]

Originally Posted by LivNLearn

Here's a picture, couldn't upload the video. The strut is actually compressing very easily for an inch or so between the green lines that I added to the picture. It's like there's no preload. Is this just a worn out strut or does the adaptive strut have this much "play"? I've never seen one with this much play before dampening occurs and I've checked a fair amount of them out. Was a mechanic in a previous life. If it were off of the car and you stood it upright I think you'd be able to easily depress the piston by hand an inch or so. With these being electronically controlled do they have the same preload that a gas-charged strut would have?

Something is not right. The spring should be in contact with the lower spring seat on the strut. It doesn’t contact the full circumference because it’s the end of a coil spring but it’s in contact with roughly 1/2 the circumference - I can’t even see where they’re in contact in your picture.

The adaptive struts/shocks are a conventional monotube gas charged damper with an electromechanically controlled valve stack on the piston. Except for the electromechanical valve actuation, the edc damper works just like any other monotube damper. For the front strut, the spring will be preloaded/compressed between the top strut mount and the strut lower spring seat. There should be zero play in the axial direction between the spring and the strut piston rod. If you can move the strut body any distance without the piston rod immediately moving the same amount then it suggests either the strut is blown or the top mount has failed. Does it do this on both front struts or just one side?

[M3SQRD]

Originally Posted by LivNLearn

Here's a picture, couldn't upload the video. The strut is actually compressing very easily for an inch or so between the green lines that I added to the picture. It's like there's no preload. Is this just a worn out strut or does the adaptive strut have this much "play"? I've never seen one with this much play before dampening occurs and I've checked a fair amount of them out. Was a mechanic in a previous life. If it were off of the car and you stood it upright I think you'd be able to easily depress the piston by hand an inch or so. With these being electronically controlled do they have the same preload that a gas-charged strut would have?

What’s the strut top mount look like from in the engine bay? Take a picture of the central nut and the three (or five - BMW changed from 3 to 5 in 2015-2016 I believe) screws that bolt the strut top mount to the strut tower.

[LivNLearn]

Originally Posted by M3SQRD

Something is not right. The spring should be in contact with the lower spring seat on the strut. It doesn’t contact the full circumference because it’s the end of a coil spring but it’s in contact with roughly 1/2 the circumference - I can’t even see where they’re in contact in your picture.

The adaptive struts/shocks are a conventional monotube gas charged damper with an electromechanically controlled valve stack on the piston. Except for the electromechanical valve actuation, the edc damper works just like any other monotube damper. For the front strut, the spring will be preloaded/compressed between the top strut mount and the strut lower spring seat. There should be zero play in the axial direction between the spring and the strut piston rod. If you can move the strut body any distance without the piston rod immediately moving the same amount then it suggests either the strut is blown or the top mount has failed. Does it do this on both front struts or just one side?

Based on what you're saying it sounds like there's no gas remaining in either strut. I've not seen a gas-charged strut compress this easy for an inch. I also understand what you're saying about the spring not making full contact with the lower seat.

Here are more pictures of the spring seat. I can't get great ones as I can't hold the flashlight and the camera at the right angles together. And yes, it does this on both sides.

I put the video on YouTube if you'd like to see it.

Here are more pictures of the spring seat. I can't get great ones as I can't hold the flashlight and the camera at the right angles together. And yes, it does this on both sides.

[LivNLearn]

Originally Posted by M3SQRD

What’s the strut top mount look like from in the engine bay? Take a picture of the central nut and the three (or five - BMW changed from 3 to 5 in 2015-2016 I believe) screws that bolt the strut top mount to the strut tower.

Here's the strut mount.

[LivNLearn]

For anyone else that may run into this I took the car to a local indy BMW-only specialty shop. They checked the car out and found nothing wrong with it aside from the right strut just starting to leak.

We then went for a ride and when it started vibrating I told the technician "there it is". He said he could feel it too. I asked what was causing it and he said it's because it's a convertible. There's more flex in the car and it's not uncommon for this to occur.

If you Google this you'll find scuttle shake and cowl shake.

Guess the dealership is unaware of this or they'd of told me long ago.