Xantia Suspension Oscillation (Fixed! solution on page 2)

bostwickenator · Post by **bostwickenator** » 24 Sep 2010, 23:12

I have a Xantia 96 estate (petrol 2.0i, auto, hydractive) and wondered if anyone could help me answer a few questions about the suspension. I find that when I hit bumps in the road I fairly often (depends on speed and bump shape) get a oscillation or harmonic if you will. The car will bounce up at the front then the back then oscillate between the two noticeably 3 or so times. In another car I would say it felt like soft shock absorbers but I wouldn't have a clue with a Xantia *lol*. Turning hydractive to sport (light on) makes the ride a little less disconcerting but not what I would call sporty. I believe the sphere's have leaf valves that do the damping? Do these get weak over time? I should also mention that the rear end drops quite rapidly after engine off. Sometimes it can take five minutes sometimes 30 seconds.

Any answers or pointers would be appreciated, I'm quite out of my depth here.

Dommo · Post by **Dommo** » 24 Sep 2010, 23:33

Do you know whether the spheres have ever been changed? There's 8 on a Hydractive anti sink car!

Healthy Citroens could be described as bouncey to most people, it depends on how severe the bounces are. If it's a harsh bounce some of the spheres sound low on pressure and need replacing, however if its a slow wallowey bounce over a speed bump for example, that's fairly normal,

bostwickenator · Post by **bostwickenator** » 25 Sep 2010, 01:17

Unfortunately I don't know if the spheres have been changed. Is there a way to test their pressure?

The bouncing is wallowey at around 60hz so it seems very noticeable. My previous Xantia felt very different but it was the Hatch and didn't have hydractive so maybe it is just that.

Just to make sure I understand correctly old spheres with low pressure will cause sharp bumps because the gas has less of a cushioning ability? Where as 'good' spheres will give a bouncier more floating ride. If my old spheres were flat I think I preferred that +_+.

Jimothy · Post by **Jimothy** » 25 Sep 2010, 06:55

My old Xantia developed this problem - it is linked with the loss of nitrogen gas from the spheres, I believe.

I read that the spheres can be "topped up" if the loss is within certain limits, but if they've gone too far then the spheres need replacing, which is an expensive job in my experience, so get it looked at sooner rather than later.

bostwickenator wrote:around 60hz

Don't reckon that's right BTW (if it is then it's not the same problem afterall) - 60Hz means 60 cycles per second, which would feel like a buzz (like driving over a cattle grid at speed) rather than a bounce.

DickieG · Post by **DickieG** » 25 Sep 2010, 07:45

The problem could be down to some sphere's being low on gas or having the wrong sphere's fitted, they can be tested for pressure, I and one or two forum members have sphere pressure testers, whereabouts are you as I'm willing to test them for you.

As for the rear of the car dropping that may well be down to the rear Hydractive block not closing which could also be a cause of the wallowing as that could mean that the rear of the car is permanently stuck in soft mode. Have you tried pushing down on the suspension when the engine is running then turning it off closing all doors, waiting for 30 seconds after which the Hydractive suspension should switch off (you should hear a faint click under each end of the car and a buzzing noise stop) then again pushing down on the suspension, at this point the suspension should have switched to firm and be harder to push down on.

bostwickenator · Post by **bostwickenator** » 25 Sep 2010, 07:53

DickieG wrote:The problem could be down to some sphere's being low on gas or having the wrong sphere's fitted, they can be tested for pressure, I and one or two forum members have sphere pressure testers, whereabouts are you as I'm willing to test them for you.

As for the rear of the car dropping that may well be down to the rear Hydractive block not closing which could also be a cause of the wallowing as that could mean that the rear of the car is permanently stuck in soft mode. Have you tried pushing down on the suspension when the engine is running then turning it off closing all doors, waiting for 30 seconds after which the Hydractive suspension should switch off (you should hear a faint click under each end of the car and a buzzing noise stop) then again pushing down on the suspension, at this point the suspension should have switched to firm and be harder to push down on.

Unfortunately I'm in New Zealand so it would be a bit of a trip to get the spheres to you. I'll check with our local Citroen branch and see if they can test them for me.

As for that test you described I'll do it as soon as my girlfriend gets the car home. I figured the humming would be related to the suspension but the manuals don't mention it.

bostwickenator · Post by **bostwickenator** » 25 Sep 2010, 07:56

Jimothy wrote:My old Xantia developed this problem - it is linked with the loss of nitrogen gas from the spheres, I believe.

I read that the spheres can be "topped up" if the loss is within certain limits, but if they've gone too far then the spheres need replacing, which is an expensive job in my experience, so get it looked at sooner rather than later.

bostwickenator wrote:around 60hz
Don't reckon that's right BTW (if it is then it's not the same problem afterall) - 60Hz means 60 cycles per second, which would feel like a buzz (like driving over a cattle grid at speed) rather than a bounce.

Very interesting I'll definitely ask about this at Citroen hopefully it is somewhat cheaper than a new set. And you are completely right about the speed I in fact meant 1Hz. (I've got to start proofreading)

addo · Post by **addo** » 25 Sep 2010, 09:21

Get in touch with Chris de Jong if you need new (aftermarket) spheres. He constantly sells them on TradeMe at very decent rates.

All spheres should be tested regularly - even a "new" one before it's fitted!

Post by **xantia_v6** » 25 Sep 2010, 21:28

Just to cover the simple things first...

Have you exercised the system to expel any air in the suspension circuits? Air bubbles can give symptoms similar to those you describe.

kevlights · Post by **kevlights** » 19 Nov 2010, 08:59

http://www.fastfrogs.co.nz/index.php

http://www.fastfrogs.co.nz/index.php/topic,5719.0.html

http://www.trademe.co.nz/Browse/Listing ... =324761990

and for some home work this

http://www.attfield.dircon.co.uk/Hydrau ... Xantia.pdf

explains the ins and out of the suspension

next time you are passing a car sales yard take the Citroen you see on sale for a run to compare with yours ,cheap comparo info to be had first hand!!

Post by **Peter.N.** » 19 Nov 2010, 09:36

The simplest way to check the spheres is to bounce each corner of the car with the engine running. A hydractive with good spheres should give a movement of 4"-6" at the rear and a little less at the front, if you are not getting anything like that spheres need replacing.

Peter

citroenxm · Post by **citroenxm** » 19 Nov 2010, 10:17

Theres always a problem with "Newer" owners to Citroens identifying the citroen "Bounce" and "Float"

Im not point the "Newer Owner" description at you, bostwickenator, or anyone in particular..

Theres a VERY obvious difference with the Flat Bounce and the Gass Float!

The bounce gives a sort of "Rubbery" type of Flex bounce, were as gasses spheres give a nice smooth floaty bounce, its NOT a bounce really, more like a Shot shock absorber on lesser "Normal" boring cars...

Paul

Post by **xantia_v6** » 19 Nov 2010, 10:37

There seems to be a bit of a time-warp in this thread, the original post was 2 months ago

bostwickenator · Post by **bostwickenator** » 26 Nov 2010, 19:48

Lets do the time warp again!

Since I've posted this I've noticed that the bounce is only in the front suspension the back rides perfectly. Would this further suggest that it is the front spheres that have lost pressure?

addo · Post by **addo** » 26 Nov 2010, 21:08

It's also well possible your front ride height's excessive. Have a look about halfway down the page in this linked thread, for my photo of unmolested ride height at the front with motor running.

http://www.frenchcarforum.co.uk/forum/v ... c&start=15

French Car Forum

Xantia Suspension Oscillation (Fixed! solution on page 2)

Xantia Suspension Oscillation (Fixed! solution on page 2)

you may need a spheres and LHM flush out with filters clean