[pablom2c]

Hi,

I bought my 2020 M2C used around 5 months ago and right now it only has 5,500 miles.

When driving normally over smooth roads either fast or slow I don't notice any strange noises, but when driving slow over sharper repetitive bumps and irregularities or a pebble road I feel a rattle from the front end, it seems to come from the bottom of the car as if something is loose? Over single regular speed bumps or cat eyes there is no noise.

Is this a normal suspension noise from the M2C during repetitive bumps? I haven't noticed that the rattle stops if I brake, it still seems to be there with or without braking. Steering feels good, nothing strange.

The car is stock, it only has Eventuri intakes and M Performance front lip (this doesn't feel loose but could it rattle?). I also looked in the engine bay and didn't notice anything being loose.

I have an oil change coming up soon and will ask the shop to check for anything loose in the suspension/brakes but if you have any ideas I would appreciate it.

Thanks.

[Brokenbones]

Originally Posted by pablom2c

Hi,

I bought my 2020 M2C used around 5 months ago and right now it only has 5,500 miles.

When driving normally over smooth roads either fast or slow I don't notice any strange noises, but when driving slow over sharper repetitive bumps and irregularities or a pebble road I feel a rattle from the front end, it seems to come from the bottom of the car as if something is loose? Over single regular speed bumps or cat eyes there is no noise.

Is this a normal suspension noise from the M2C during repetitive bumps? I haven't noticed that the rattle stops if I brake, it still seems to be there with or without braking. Steering feels good, nothing strange.

The car is stock, it only has Eventuri intakes and M Performance front lip (this doesn't feel loose but could it rattle?). I also looked in the engine bay and didn't notice anything being loose.

I have an oil change coming up soon and will ask the shop to check for anything loose in the suspension/brakes but if you have any ideas I would appreciate it.

Thanks.

Yup. Same going over cobblestone road. Think maybe it's noticeable because the disconnect between the numb electric steering and vibration feedback you'd normally feel through the wheel on a hydraulic steering rack?

[pablom2c]

Thanks for your comments that might be true also. I was also thinking that since the M2C has less soundproofing than regular BMWs in rough roads the suspension noises are more obvious. I also have the active sound design disabled, not sure if that also cancels other road noises or if it only generates fake engine sound.

[DanG]

Originally Posted by pablom2c

Thanks for your comments that might be true also. I was also thinking that since the M2C has less soundproofing than regular BMWs in rough roads the suspension noises are more obvious. I also have the active sound design disabled, not sure if that also cancels other road noises or if it only generates fake engine sound.

ASD is only fake engine noise. I have mine disabled too.

[Billy_BMW]

Absolutely no noise from my M2C and it’s on KW V3’s. If there’s a rattle on stock suspension, there’s a problem.

[ROBM2C]

I had this same problem ...unknown front end rattled ...pings etc ...swapped out the oem suspension and wouldn't you know ....zero rattles and pings now .

[Karmic Man]

No rattles, I mean real rattles like a 20 years old shitbox with a lose steering rack

[Rumbloki]

I hear a rattle from under the front end on startup. Is this normal?
Also, rattles in the rear on startup. I assumed this has to do with valves moving?
I've read on here that some cars were delivered with loose bolts on rear exhaust hangers.

Maybe I can find time to get under the car this weekend.

[3t3p]

OMG my car today, is doing as you describe. It occurs on slower bumps, is not linked to braking or accelerating. At first not doing it on steering then later seemed to be.

Its fairly high pitched but not a solid sound, tried to record with my phone to no avail.

On way to work sounded like debris got flung up underside of car at one point and wonder if started from there?

Car seems fine and getting coilovers put in in three weeks anyway I suppose...

[EDWYER]

Get the upper strut mounts checked.

[Encanto]

Front left rattle?

[3t3p]

Getting mine checked this Thurs

[3t3p]

Back from garage, noise gone.

Here is their documentation:

'Investigated creaking noise from FOS mainly when turning. Checked tightness of control arms, rack, subframe. Stripped brake off to remove wheel bearing and check for any movement between housing, none found, cleaned off corrosion and rebuilt, noise still there. Eventually traced noise from between shock absorber and bearing housing. Applied a lock compound on joint and rebuilt, noise now gone.'

[M Fifty]

So the strut was moving in the bearing housing?

[3t3p]

I thought it was odd, between shock absorber and housing. Don't know if they mean pinch bolt.

They def sorted it though!

[warrenw]

I have the same problem.. But I'm on Ohlins plus camber plates. I had a shop re-grease the "cups" the suspension sits in which requires taking the coilover out partially, then they put it back together and the noise went away.
For a month. Now it's back.

[arturlnyc]

Same issue on my 2019 M2C - Driver's side front rattle over bumps at 16 MPH.

Been reporting this issue to my local dealer over the past couple of years. No resolution to date.

Going in for service on July 7th/22. Will report back.

EZ

[M Fifty]

Originally Posted by warrenw

I have the same problem.. But I'm on Ohlins plus camber plates. I had a shop re-grease the "cups" the suspension sits in which requires taking the coilover out partially, then they put it back together and the noise went away.
For a month. Now it's back.

Okay, noting the date on the post - I'll bite.

The bottom of the front strut is meant to be clamped into the Front Carrier (31212284001 and 31212284002) such that it cannot move independently. At all.

Your shop's "solution" was to add lubricant?

Go somewhere else in future...

[pablom2c]

Could it be the steering rack is noisy over slow bumps and it is not really a suspension related knock?

[pablom2c]

Originally Posted by 3t3p

OMG my car today, is doing as you describe. It occurs on slower bumps, is not linked to braking or accelerating. At first not doing it on steering then later seemed to be.

Its fairly high pitched but not a solid sound, tried to record with my phone to no avail.

On way to work sounded like debris got flung up underside of car at one point and wonder if started from there?

Car seems fine and getting coilovers put in in three weeks anyway I suppose...

Did the coilovers fix the rattle?

[Carrera2RS]

I had a slightly worn roll bar drop link and that was replaced and cured a small 'knock' over low speed bumps

[D.Yooras]

Originally Posted by M Fifty

Okay, noting the date on the post - I'll bite.

The bottom of the front strut is meant to be clamped into the Front Carrier (31212284001 and 31212284002) such that it cannot move independently. At all.

Your shop's "solution" was to add lubricant?

Go somewhere else in future...

I take it you haven't done front end work. Let me explain how this situation worked:

1) To find that problem the shop has to be good btw, that approach was methodically and correct.

2) The struts AND spindles on M2s are aluminum. Aluminum doesn't have the same characteristics under compression (clamping) that steel does (or even steel and aluminum clamped together). Unlike steel, aluminum crushes but doesn't spring back, or at least not as much. That means when you bolt two pieces of aluminum together, and torque to spec, the torque that bolt is applying will be reduced overtime. When that happens, the two pieces of aluminum will squeak and creak like crazy unless the bolt is re-torqued.

3) Given all the forces at work on the area where the strut meets the spindle, there is a lot of potential for movement as clamping force reduces. In fact, since the spindle is a pitch style bolt, the clamping force is exponentially higher per degree of rotation.

4) Proper lubrication and cleaning of the mating surfaces, is critical to ensuring the two parts are sufficient attached to each other. This is especially true after the parts had run loose for any noteworthy period of time. This is a somewhat known problem on these cars, my strut bolts where not tight enough when I installed camber plates and they had never been serviced by the previous owner.

So don't throw that shop under the bus, especially when they did things the right way AND solved the problem.