2015 40d m sport bouncing/bunny hopping

[Justk2020]

Hi all,

First post....go easy pls.

My X5 is intermittently bouncing/bunny hopping.

By intermittently I mean one drive is fine...next drive it bounces. Not intermittent whilst driving if that makes sense

By bouncing I mean really...like when a person is learning to drive. Like being oj a space hopper. It feels a bit crashy at the same time.

Sods law it drove fine to its mot. The couldnt see anything...checked bellows, springs...only thing they found is battery was only 51%. They charged it up. Lol and behold drive home....bounced all the way.

Any ideas? I did read some stuff about compressors (expensive) and dessicants (cheap).

Regards,

K

[suitedcboy]

If the air suspension in rear is the cause then it would also have ride height that is wrong. On level ground that vehicle should sit more or less level with a slight rear rake, i.e., the rear will be a bit higher. Take note of the distance from top of tire to the wheel opening. It will likely be 1 inch or close. Now when it has one of the bouncing-bucking episodes pull over on a level spot and check that the rear is still at the same height. If it is an inch heigher or an inch lower then air suspension has an issue. Full deflation will set it about 1 inch low and it will ride rough and buck. Full over inflation will put it about 1 inch high from standard and the result will be stiff bucking ride. The system does side to side levling so you will need to take note and check both sides as it could be a one side problem. Adaptive suspension issues that set shock damping at the stiffest setting will cause rough ride but no issues with ride height. Adaptive damper settings going full soft would not usually cause your issue but I suppose it could depending on the degree of irregularity in the pavement.

[Justk2020]

Thanks for response

So i went and looked.

Car has been left on flattish roadside for 6 hrs since bouncy run...both side...rear was well up...like a 4 inch gap (on 255/50/r19 wheels/tyres).

Took for a 0.5 mile drive..no bouncing.

Parked in same place.

OSR gap was unchanged (4 inch or so)
NSR gap was down to 1 inch or so.

[KnudsonM3]

https://f15.bimmerpost.com/forums/sh....php?t=1984234

Get new shocks.

[F15_SGM]

Originally Posted by Justk2020

Thanks for response

So i went and looked.

Car has been left on flattish roadside for 6 hrs since bouncy run...both side...rear was well up...like a 4 inch gap (on 255/50/r19 wheels/tyres).

Took for a 0.5 mile drive..no bouncing.

Parked in same place.

OSR gap was unchanged (4 inch or so)
NSR gap was down to 1 inch or so.

You have to park it an inclined and unleved spot for the bags to loose air.