how to prevent XM from dropping?

kcleong18 · Post by **kcleong18** » 15 Sep 2005, 16:44

I hv several instances of the car dropping from normal height normally when something like the steering is turned. The last instance happens when the door is open after some testing of the acc and suspension spheres. These 'turbulence' drops are quite unnerving and am definitely sticking to the no crawling under car without jacks advice.
So wondering here whether is there anyway to prevent such drops from happening or is there something drastically wrong with my XM 2.0 1991?

NiSk · Post by **NiSk** » 15 Sep 2005, 16:51

Have you checked that there is gas in the accumulator sphere?
Does the car have hydractive suspension (with a switch that allows you to change between normal and "sport" suspension?
//NiSk

jeremy · Post by **jeremy** » 15 Sep 2005, 17:36

This sounds to me like sticky front struts or rear trailing arm bearings. Car is stopped - accumulator slowly discharges through the sustensionand the suspension spheres slowly discharge through the height correctors etc. Car doesn't drop due to suspension friction until such time as its jogged - and then drops rapidly.
New struts and/or trailing arm bearings would improve the ride.
Jeremy

Rostami · Post by **Rostami** » 15 Sep 2005, 18:25

What is the state of the LHM and the hydraulic circuit? all clean and nice?

kcleong18 · Post by **kcleong18** » 16 Sep 2005, 07:36

NiSk,
Accumulator is most probably knackered and will hv to be regassed or replaced but meanwhile wud like to try testing them first.Yes suspension is Hydractive 1.
Jeremy,
XM goes up and down smoothly and so far the car drops only when the engine is idling/moving.This occur on all four so I am not sure whether sticky struts comes into play and I hv not experience any drops if the engine is stopped and me trying to test suspension spheres by sitting at the back.Anyway ur line of reasoning is food for thought.
It is quite violent like a sudden loss/release of pressure and funny thing is immediately the system starts to rise.Has a feeling it is the H1 sensors coupled with the the inability to equalise pressure somewhere... maybe the centre sphere??
Rastami,
LHM is bright and green.. just got the car a couple of months back.. not in vy good conditions .. leaks everywhere so is having fun trying to get everything back to a 'reliable' ride.
Read of a few instances of this happening but so far hv not managed to find any explainations so wud be happy for more feedback from fellow enthusiasts.
Tnxs agn.

ItDontGo · Post by **ItDontGo** » 16 Sep 2005, 13:50

Isn't this problem something to do with the centre sphere isolation valves. They are supposed to open at some point to equalise the pressure in the centre sphere and the suspension spheres aren't they? I dont remember what happens when now but the computer is supposed to do something when the door opens or something else like that happens. Surely someone who doesn't have a sive of a memory will know what I am on about.
I did read somewhere that they had to get around the problem of the car suddenly jumpong to a different height because when people get out etc the spheres are all at different pressures?

kcleong18 · Post by **kcleong18** » 19 Sep 2005, 12:44

Hi ItDontGo,
I have read somewhere also abt this problem due to the centre sphere or valves.But my understanding is the system will equalise pressure everytime a door is opened so why the drop after a while? Unless the Hydractive electrovalve is not working (radio tests seems to indicate otherwise) which will set the system in permanent hard mode but then the centre spheres will never come into play.
Or is there another set of valves?
Also I hv no cases of the car gaining height so far.
Just need an explaination..bye