[Inglewood]

Have a 2017 330i m sport wagon - previous owner installed BC racing coil overs....probably would've gone another direction with coilovers, but is what it is. Love the ride height; however, under 35 mph, there are noticeable thunks/clunks over small bumps in both front wheels as well as one of my rears on the passenger side. Everything seems tight from what my local shop tells me...obviously BMW wont touch aftermarket parts and none of my indy shops are instilling confidence in their ability to diagnose.

I've read issues about greasing pinch bolts and other suspension components on f3x cars which is supposed to rectify noises. At this point, the thunking is annoying to the point that I consider selling the car at times - or investing another 3k into a KW street comfort or V2 system. I would rather not pay 3-4k to have the same end ride height if possible just to solve the low speed clunks - not sure if anyone has had similar experiences or have areas I should check into that might be causing the issue.

Thanks in advance!

[Logicoeur]

With BCs ensure you have enough preload on the springs. Check the top hat bolt, and check your control arms for worn bushings. The bushings seems to clunk and thunk if they are moved after factory install and they were on their way out (eg installing new suspension).

[SuperLomi]

Don’t BC coilovers come with camber plates? The monoball bushing on camber plates is a weak point known to wear and cause noise, as they aren’t great at absorbing axial loading.

[Honeybadger23]

Originally Posted by Inglewood

Have a 2017 330i m sport wagon - previous owner installed BC racing coil overs....probably would've gone another direction with coilovers, but is what it is. Love the ride height; however, under 35 mph, there are noticeable thunks/clunks over small bumps in both front wheels as well as one of my rears on the passenger side. Everything seems tight from what my local shop tells me...obviously BMW wont touch aftermarket parts and none of my indy shops are instilling confidence in their ability to diagnose.

I've read issues about greasing pinch bolts and other suspension components on f3x cars which is supposed to rectify noises. At this point, the thunking is annoying to the point that I consider selling the car at times - or investing another 3k into a KW street comfort or V2 system. I would rather not pay 3-4k to have the same end ride height if possible just to solve the low speed clunks - not sure if anyone has had similar experiences or have areas I should check into that might be causing the issue.

Thanks in advance!

I just installed the godspeed mono max coilovers on my 2016 bmw 340i m sport

Had clunking, squeeking.

Once the suspension settled
200 miles

I took all the wheels off
And removed and reinstalled the coilovers.

Double checked my spring preload
Measured the shock absorber for front and rear. Tightened all my suspension bolts I could find.

Sounds went away.

Seems a bit excessive but the clinking noise is extremely annoying

Hope this helps.

[Onizukachan]

I had a tinny rattling noise coming from the fronts suspension on tiny oscillations at moderate speeds after installing my kws.


I was wrong. It was the rear suspension and a socket had bottomed out when I was reinstalling one of the rear bolts so the bolt was jsut shy of being tight. That was the rattle I was hearing. But it really did sound feel like the front.

Just a warning to double check the rear that DOESNT make noise caus$ maybe it is the one that really is!

[Watsey]

In addition to the other suggestions, also check the ball joints in the drop links. If these wear they can can cause a lot of rattling/thunking through the suspension and into the chassis.

[TheM3Chase]

Probably the sway bar links. I had the same thing happen to me. It's hard to find the play on the lift because the joint is loaded

[xpro]

Replace with B16 PSS10 coil overs. All your problems will go away if you like your car

[casualDIYer]

Originally Posted by SuperLomi

Don’t BC coilovers come with camber plates? The monoball bushing on camber plates is a weak point known to wear and cause noise, as they aren’t great at absorbing axial loading.

This would be my guess as well. If you look at the factory top hat, you will see the strut's threaded rod is bolted to it at a point where there is a massive rubber bushing within the top hat housing. In my experience Streetable Camber plates have not minimized vibration as well as the stock top hats. Then again, with the stock top hats, that can help you become familiar with your local tire dealer.

[brigade24]

Originally Posted by Logicoeur

With BCs ensure you have enough preload on the springs. Check the top hat bolt, and check your control arms for worn bushings. The bushings seems to clunk and thunk if they are moved after factory install and they were on their way out (eg installing new suspension).

+1. Add sway bar end links to this list.

My top hat bearings are on their way out and they have started making the same thunking noise.