Xm Problem, THE REAR GO UP AND DOWN

HELLO TO EVERONE ITS MY FIRST TIME HERE AND I AM HAPPY TO BE HERE.
SO I HAVE CITROEN XM 1999 3000CC V6 XFZ ENGINE,THE PROLEM IS THAT THE CAR SINK ONLY AT THE REAR AFTER 5 SECOND.
BUT THE BIG PROBLEM IS THAT WHEN THE CAR IS WORKING ENGINE RUNING THE CAR GO UP AND DOWN ONLY IN THE REAR AND IT DOSNT STOP DOING THIS PLEASE SOME HELP
CU YARON

When I had this problem on my V6 some years ago it was caused by one of the rear suspension units having an internal leak. Fluid would leak back to the reservoir, the back end would drop, height corrector would open and send fluid to suspension unit, back end would rise, height corrector would shut off, fluid would leak etc. etc..

Your car should have anti-sink fitted. This isolates the suspension legs from the rest of the system, so when you stop the engine if the back end then drops all the way down it's almost certainly the suspension units leaking.

The easiest way to check is to look at the return pipes at the reservoir. Alternatively you could drive the back end up on ramps and then, with the engine running, pull off the return rubber hose from each gaiter in turn to check for leakage. But please make sure the ramps are high enough for you to work safely underneath.

Derek

This post has been edited by DerekW on November 08, 2008 12:33 am

Welcome Yaron.

Reading the description of the problem, it really is down to interpretation and Derek see's
it differently to me!! That's the beauty fo this forum!! Mind, what you describe Derek,
sounds like the worst ever PITA suspension problem/symptom to suffer!!

It sounds to me like the front won't go up or down but the back does?
If that's the case you've either:

• got a problem with the front height corrector is disconnected or sludged internally,
• the front spheres are totally flat, preventing any suspension movement in normal driving
• or the front strut is damaged and not freely moving up and down
according to road deflections and sphere reaction pressure - not as easy/likely as a rear
ram being belled and jammed inside the strut body.

Does the car freely select different heights through your selection of the manual height
adjustment lever on the central console?

Andrew

This post has been edited by Andmcit on November 08, 2008 12:58 am

has this car been stood for some time and not used?

if so, likely to be a seized front height corrector and a partially seized rear one.

lots of penetrating oil on all moving parts to the height correctors and under the rubbers of the height correctors themselves, and inside the plastic linkages.....

thanks to all the help all of you gave me
i wiill try everthing you said
btw:how did you know the car stood for almost a year?

thanks to all i will be around

well guys i did my check and its the right rear suspension that has very big internal leak and cause the drop of the car to zero.
do i have to replace all the unit of the sospension or there is kit for changing the rubber seal inside the piston?
thanks yaron

Hi Yaron,

I'm sorry my PITA (pain in the arse) diagnosis was correct, but the symptoms were very familiar to me.

Where are you? I suspect not in the UK.

I had my faulty unit replaced by a specialist company called Plaiedes and I know they used to overhaul rear suspension units so repair kits may be available.

What seems strange to me is that this is an unusual failure and yet our two cars, both V6s built in 1999, have suffered it. Did Citroen have a bad batch of ram seals do you think?

Derek

This post has been edited by DerekW on November 14, 2008 06:04 pm

Good on you Derek!!!

Haven't had or seen/heard this one myself! I've seen belled rams jam in the strut bores and
lock rigid - something only likely on the rear of an Xm but this was a GS front IIRC.

Still, it IS a real PITA!

Andrew

Hi Yaron,

Welcome to club-xm,

One possibility is that someone may have been trying to adjust the height of the car manually by pressing or pulling on the height corrector shaft with some tool or other. In which case the small shuttle valve inside the height corrector may be bent and sticking in the bore of the HC. A large change in height of the car is needed to overcome the friction of the spool sticking in the bore and it moves in jumps instead of smoothly.

If you have a spare it might be worth changing the HC for another one or, if not, dismantling the existing one and checking for the smooth movement of the spool inside the HC.

Cheers

noz