My 1992 XM 2.1 SED hatchback is starting to exhibit unusual symptoms. When driving on a motorway/smooth A road the ride is smooth, if a little floaty. On any surface other than smooth the ride seems harsh and every bump in the road seems to be fed into the body shell. I have experienced flat rear spheres before on another car and it doesn't feel like this. Also if a smooth road has a slight uneven surface, (M11 near Duxford) the car bounces as if there is no damping control whatsoever. [V]
In sport mode the car corners flat but still exhibits excessive bounce. It is NOT excessively hard. (I can liken it to driving a conventional car with worn shocks, only the wheel doesn't bounce uncontrollably and lose grip)
The main accumulator sphere was replaced last year with a new Citroen part. It also had LHM flush plus new filters and fluid at the same time. However when stationary a loud hissing noise starts up but stops when I apply slight pressure to the steering wheel. Apart from these symptoms the car is fine.
Is this a indicative of spheres on the way out or could it be something else.
Thanks in advance
Doc
XM ride quality
Moderator: RichardW
Don.t know about ride quality but hissing sound is from flow distributor...
I have same sound and i read somwhere (i think from BX diy site) that that means that Flow distributor is worn out (last stage)...
I cahanged myne for some used one (improved steering) but this one is still hissing so i have to dismantle old FDV taht i took out from my car and rebuild it...
REgarding bouncing i have similar problem but i will go at some specialits shop to check all the hydra stuff (and refill if needed)...
REgarding noise and bumps i have worn out rear arms bearings so that my result in more noise and road unevenes transfer to chasis, they skweek a little and i feel like rear part is a little restless (i tend to replace them any day now...)
ZEGA
I have same sound and i read somwhere (i think from BX diy site) that that means that Flow distributor is worn out (last stage)...
I cahanged myne for some used one (improved steering) but this one is still hissing so i have to dismantle old FDV taht i took out from my car and rebuild it...
REgarding bouncing i have similar problem but i will go at some specialits shop to check all the hydra stuff (and refill if needed)...
REgarding noise and bumps i have worn out rear arms bearings so that my result in more noise and road unevenes transfer to chasis, they skweek a little and i feel like rear part is a little restless (i tend to replace them any day now...)
ZEGA
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cliveparsons
- Posts: 4
- Joined: 04 Apr 2004, 14:22
- Location: United Kingdom
- My Cars:
If the car is floating fine over long road waves, it means that it's in soft mode (so hydractive system is working) and that middle hydractive spheres are ok.
Harsh ride on sharp bumps can be caused by flat corner spheres (how old are they?). Middle spheres are responsible for floating, but can't take short bumps, because they have only central bore and not whole damper valve, like corner ones.
Corner spheres can be checked when the car is in hard mode (switch the engine off, close the doors and wait until you hear the click from stifness regulator) by pushing front and rear bumper down. It will feel rock hard, but should dive gradually under your weight, within several seconds (because of very small orifices in damper valves). It should be about 2 cm front / 4 cm rear with new spheres.
Of course, it can be also something else.
Harsh ride on sharp bumps can be caused by flat corner spheres (how old are they?). Middle spheres are responsible for floating, but can't take short bumps, because they have only central bore and not whole damper valve, like corner ones.
Corner spheres can be checked when the car is in hard mode (switch the engine off, close the doors and wait until you hear the click from stifness regulator) by pushing front and rear bumper down. It will feel rock hard, but should dive gradually under your weight, within several seconds (because of very small orifices in damper valves). It should be about 2 cm front / 4 cm rear with new spheres.
Of course, it can be also something else.
Hi alexx
the rear spheres were changed 18 months back by the supplying dealer as back end was very harsh on the test drive. He said they had a couple of spheres so they put those on. Car has been fine up until last couple of months where - as in my previous inquiry, the ride is getting choppy.
Clive, apart from the possibility that the new spheres were duff then it could be the rear height corrector which just needs a good clean up and lube with WD40 or similar. When my XM was showing exactly the same symptoms I had a look underneath and noticed a build up of general road crud and surface rust that was preventing the rod/link assembly from transfering movement to the valve. This lies under a rubber cover and has a black plastic rod sticking out. One end is linked to the rear anti-roll bar and the other to the height selector rod via a linkage. Clean and lube and then play with the ride height selector. If this doesn't improve things then the Height Corrector valve may be faulty. Let us know how you get on.
Doc
the rear spheres were changed 18 months back by the supplying dealer as back end was very harsh on the test drive. He said they had a couple of spheres so they put those on. Car has been fine up until last couple of months where - as in my previous inquiry, the ride is getting choppy.
Clive, apart from the possibility that the new spheres were duff then it could be the rear height corrector which just needs a good clean up and lube with WD40 or similar. When my XM was showing exactly the same symptoms I had a look underneath and noticed a build up of general road crud and surface rust that was preventing the rod/link assembly from transfering movement to the valve. This lies under a rubber cover and has a black plastic rod sticking out. One end is linked to the rear anti-roll bar and the other to the height selector rod via a linkage. Clean and lube and then play with the ride height selector. If this doesn't improve things then the Height Corrector valve may be faulty. Let us know how you get on.
Doc