Shock problem?

[wonsong82]

I have 2015 35is at 40k miles.
I think my car has bad shocks.
When I drive through highway, even very small pothole I hit, the car gets impact really hard, as it feels like i am in a car accident.
I am not a car guy, I need help here. Do I need to replace my shocks?
any direction what to buy to replace?

[Marcoose]

40K miles seems too early for the adaptive suspension to go bad. But it’s possible.

You can replace only the bad shock, or the pair for better balance, or go with aftermarket, which is far better.

[B21]

My 35is shocks and springs were completely goosed when I bought the car with 50k miles on it.

The replacement costs of the 35is are very expensive if OE parts are used.

There are some Chinese copies available.

Never replace a single suspension unit..minimum in pairs across the axle…preferably all 4 ..

Some folks go with new springs and shocks from Bilstein or others..

It’s one of the many Achilles heels of the 35is..

[Marcoose]

Originally Posted by B21

Never replace a single suspension unit..minimum in pairs across the axle…preferably all 4 ..

It's unquestionably the right way to do it. With the exception of financial constraints. A new set of shocks, installed, is in the thousands. There are those odd times that one new shock is better than a busted shock. Just a humble opinion.

[B21]

Originally Posted by Marcoose

It's unquestionably the right way to do it. With the exception of financial constraints. A new set of shocks, installed, is in the thousands. There are those odd times that one new shock is better than a busted shock. Just a humble opinion.

You’re absolutely correct…I take , rightly or wrongly the more brutal view..it’s a high performance car..if you can’t afford to keep it an appropriate state commensurate with its performance then time to buy….

A low performance non entity..

I did say it was brutal..

Am I’m being unreasonable?

[wonsong82]

Chinese copies? where can i find them.

[KennyP]

Be cautious with those chinese copies...

They sell the same shock for 28i, 30i, 35i and 35is...

but in BMW parts catalogue 28i and 30i use one partnumber shock...
and 35i and 35is use totally different partnumber shock...
They are probably different due to different weight of the car... twin turbo I6-s are heavier...

So which one is it? are they selling a 28i spec shock to 35i owners or the opposite.. or is it something totally different... set up between the two oem parts to keep the cost down and make one fits all part...

this fact makes me not trust their product... evenmore if original shocks last only 40k-50k maybe 60k miles.... then im sure these chinese shocks dont even last that... maybe you can expect half of it and be happy if they last longer...

but they are out there.... just google and some will pop up... Front pair of these chinese shocks cost around 700 eur... basically half the price of the oem stuff...

on hubauer-shop.de front original adaptive shock is 616 eur right now..
this is -30% from the RRP of 882 eur.
So it is possible to get front pair for 1232 eur in the EU now.
This is great... when mine failed there was no such discount... full retail only...

FCPEuro sells front adaptive shocks for 35i / 35is for 850 usd a piece.

Also you can consider coilover kits and renew the whole setup: front , rear shocks and springs.

When my both front shocks started leaking... i chose to get rid of the adaptive suspension and went with KW V3 suspension with adjustable height, rebound and compression... Lucky for me there was a nice spring sale going on and i got this suspension kit almost for the price of 2 oem front shocks...
i did not buy the modules that fool the ecus to thinking that adaptive shocks are still there. I coded adaptive suspension out with inpa and Ediabas software using obd to usb cable.. and saved hundreds of euros that way aswell...

Now this V3 kit has got much more expensive... On US KWsuspension website z4 35i kit without error cancellation dummy modules is 2919 usd!
and with the modules so you dont have to do any coding is 3189 usd!...

i got my setup years ago for like 1800-1900 eur i think...

But there are cheaper kits out there aswell... maybe you will find something you like... worth a look at least...

[Steve Jarvis]

These cars are getting old and the stock foam bump stops tend to rot over time and no longer stop the shock from bottoming out. I would inspect the bump stops. It may be as simple as some new bump stops. I agree with B21 that the shocks should be fine at that mileage.

[KennyP]

dont be so sure that shocks isnt the issue... ive been on this forum for years and in the early days when these cars were still new lease machines there were some threads on front shocks failing at 35k miles... people still had warranty and got them replaced for free...

so im not suprised at all, if they failed at 40k...

[hantigg]

I have the standard suspension, or maybe the M one (non adaptive) , have to check it, but, As the front ones are leaking, shall I replace all 4?

At BMW service, they said they still work like 70% and is not necessary to replace them, but other service told me that the front ones are leaking and should be replaced.

Shall I just replace all 4 considering my Z4 has 150k km...?

[B21]

Originally Posted by hantigg

I have the standard suspension, or maybe the M one (non adaptive) , have to check it, but, As the front ones are leaking, shall I replace all 4?

At BMW service, they said they still work like 70% and is not necessary to replace them, but other service told me that the front ones are leaking and should be replaced.

Shall I just replace all 4 considering my Z4 has 150k km...?

Yup

[Drummer$Dude]

I agree with replacing all struts and shocks at the same time. The front struts will usually wear out quicker in my experience but to keep the car "in balance" replace all four corners.

My car has never been on a track and doesn't have adaptive suspension, so I went with Bilstein B4 and replaced the stock springs with Eibach Pro-Kit springs which lowers the car a bit.