[1/2M]

Hi can someone weigh in about the shocks on m240i and by what mileage do they become weak or should they be changed? My car has 20k miles, driving very carefully( still can’t miss all bumps &#128548, but it sounds like they are weak over smaller bumps lately. Also how do these work and can they be adjusted or only replaced?
Thanks in advance

[230iZTR]

I believe the service manual calls for the dampers to start getting checked regularly for wear at 60,000 miles.

The things that matter most for damper life are how hard they're being worked regularly. Loading the car up with extra weight (bigger wheels, passengers, cargo, etc), crappy uneven roads (especially potholes), and the stress of racing or spirited drives will exacerbate the rate of wear. And if you baby it on flat and smooth roads, maybe they'll last 100,000 miles or more.

The car is new enough that there's not a lot of data about longevity from cars that have added a lot of miles in just a few short years. And let's be honest here...we who inhabit the forums are far from average users, either babying our cars or modifying/racing them, so we are basically both ends of the spectrum with very few "average" users in the middle, so our experiences may make answering this question a lot harder.

[m3driver999]

Hello,

My 0.02$, the 240i has the adaptive dampers similar to 235i and the 230i THP.
Wondering if by weak, you might mean that you hear a slight rumble at low speeds? Or bumps are undamped? N or Sport settings?

The noise is an issue that the 235i had/have. Lots of talk in other threads; but from viewpoint when installing camber plates, noises increase. (though w/o camber plates a faint rumble exists - at low speeds of 10mph and near flat roads)

20K miles should still have good performance, though from OP sig = New York; 20K in NY city could equate to 50K elsewhere.

If issue is duplicable and can be heard/felt; car should still be in warranty; worth a dealer visit perhaps - though dealer's results may vary.. as in 'normal' - nothing to fix or yes, we will swap struts or control arm etc and realign at no charge. Best result, IMHO, is no parts changing by dealers if at all possible,

Re: how they work; from what I gather, below 3 mph no control, at speeds of above 3 mph the damper is adjusted by electronic solenoid on the strut and controlled by varying the current from control box in trunk looking at vehicle dynamics data as steering, acceleration sensor at strut, vehicle dynamics, etc All 4 wheels have the elec dampers

Enjoy the B58!

[XutvJet]

I've found the rear end to be softly sprung even in the Sport shock setting and made the front and rear axles feel at odds with one another as the front axle feels fairly well controlled in the Sport setting.

I recently added Dinan springs, 5mm spring spacers, and bump stops to the rear axle only and it made a MASSIVE difference in body control. I can't understate the difference. The axles now feel matched in control and gone is nearly all the bobbing/bounce on the rear axle. This is the way the car should have come from the factory.

When I removed the rear adaptive shocks, I tested their rebound manually and they gave no indications of being worn. Mine are 3.5 years old and have 35K miles.

Here's my Dinan spring install review:
https://www.2addicts.com/forums/show....php?t=1621215

[jondagger]

Originally Posted by XutvJet

I've found the rear end to be softly sprung even in the Sport shock setting and made the front and rear axles feel at odds with one another as the front axle feels fairly well controlled in the Sport setting.

I recently added Dinan springs, 5mm spring spacers, and bump stops to the rear axle only and it made a MASSIVE difference in body control. I can't understate the difference. The axles now feel matched in control and gone is nearly all the bobbing/bounce on the rear axle. This is the way the car should have come from the factory.

When I removed the rear adaptive shocks, I tested their rebound manually and they gave no indications of being worn. Mine are 3.5 years old and have 35K miles.

Here's my Dinan spring install review:
https://www.2addicts.com/forums/show....php?t=1621215

+1 100% ... also cool you did the spacer, havent heard of that.

the Dinan springs are remarkable. The rear are much tighter, yet our OEM shocks still get some turbulence over bumps. Drove my friends car with coil overs and it drives over bumps like butter, unphased. Our car still has a slight bouncing , even after the springs but a great improvement none the less. Have to take speed bumps slow when it gets to the rear. fronts are improved but not as much, such stiffness isnt needed there.

Called Dinan about the shock absorber flash. They said they will not be developing a tune for our shocks, as they already come maxed out from factory. ALL other series cars have a tune available from dinan to increase shock stiffness by ~15%. Apparently, we (M235/M240) already have that.

[1/2M]

Greatly appreciate the detailed explanations...haven’t checked the forum till now and just read the answers. What I mean by them seeming weak is that even at lower speeds over medium bumps i can hear/feel the shocks hitting the limit( as in hitting the metal or the end of the shock... don’t know how to phrase this), it’s true that the roads in New York add a lot to that, but just wondering if that’s a normal thing or should have it checked out. It also increases when pressure raises 3psi above which is understandable. I drive it mostly in comfort in the city, if I use sport it’s unbearable over bumps. The car is stock and aside from 4 people occasionally , no other heavy things were loaded in it. I suppose I’ll ask when I go for the next oil change and see what they say. Cheers and have and drive with excitement

[XutvJet]

It's the roads you're on, the sporty shock valving and spring rates, and low profile tires. The stock suspension can make crashing sounds (especially with the windows down) when you hit sharp pavement cuts and bumps. There isn't much you can do about the shocks/springs. You could get 17" rims and taller tires to reduce impact harshness. Keep in mind the 17s will look small and handling/braking limits could be reduced assuming you're on the staggered PSS setup. This is a sport car afterall thus it's going to have a pretty tight and responsive ride.

[nikijack]

Hi: I usually start thinking about changing the shocks/struts at about 20,000 miles. With Bilsteins, the change is like night and day, and they are guaranteed for life.
Jack

[John in VA]

I hope it's a while before you need to replace the shocks. I recently replaced them on my '06 E46 ZHP coupe (60k miles) with KONI FSD (Frequency Selective Damping) shocks - kept the original springs. Those have been superceded by their Special Active model. I'd certainly consider them.
http://www.koni.com/en-US/Cars/Produ...pecial-Active/

[1/2M]

All good suggestions, I also think it’s the roads mostly, but will consider changing for something better by fall. Thanks