Can anyone tell me how a xantia with hydractive II should behave when the suspension ECU is disconnected?
The front seems fine, if a little harder than normal (what I would expect) but the back is almost rigid.
This leads me so believe that the hydractive sphere is doing all the work at the back, hence why the ride is rubbish.
All spheres have been changed apart from accumulator and anti-sink.
Any ideas?
Ooooh blasted citroens....
xantia hydractive II problems
Moderator: RichardW
First, I must say my BX doesn't have hydractive suspension, so I can't tell you how rigid should be hydractive suspension in hard mode. I'm planning to buy a Xantia, so I also checked two with HA. Both had quite stiff suspension in hard mode, front and rear. I wasn't very satisfied with the ride either - it wasn't as soft as in non-hydractive models. I didn't know the condition of spheres on those cars, but I'll probably buy non-hydractive one.
Spheres on hydractive models have slightly lower pressure than in non-HA models, so the spring rates are higher, but still lower than in the cars with conventional suspension. But the damper valves are also different, with higher damping, which makes whole the difference. That's why the suspension in hard mode seems to be stiff, if you push the car down by hands, like in some sporty car. Damper valves on front spheres are also different then on rear spheres.
If you change the anti-sink sphere, rear end will probably become softer 'under hands', as anti-sink sphere is connected with rear spheres, but I think there won't be much difference in the ride, because the connection pipe have small diameter. But maybe I'm wrong.
If the ride is bad, it may also be the hydractive system sticking in the hard mode, due to some sensor malfunction. Also, check the ride height, rear arm bearings etc.
Some C5 owners fitted non-hydractive spheres to rear suspension and reported that the ride was much better, so that's the last option.
Hope some owner of hydractive Xantia can tell you more about this.
Spheres on hydractive models have slightly lower pressure than in non-HA models, so the spring rates are higher, but still lower than in the cars with conventional suspension. But the damper valves are also different, with higher damping, which makes whole the difference. That's why the suspension in hard mode seems to be stiff, if you push the car down by hands, like in some sporty car. Damper valves on front spheres are also different then on rear spheres.
If you change the anti-sink sphere, rear end will probably become softer 'under hands', as anti-sink sphere is connected with rear spheres, but I think there won't be much difference in the ride, because the connection pipe have small diameter. But maybe I'm wrong.
If the ride is bad, it may also be the hydractive system sticking in the hard mode, due to some sensor malfunction. Also, check the ride height, rear arm bearings etc.
Some C5 owners fitted non-hydractive spheres to rear suspension and reported that the ride was much better, so that's the last option.
Hope some owner of hydractive Xantia can tell you more about this.
Be aware that the switch that changes the ride from normal/sport also indicates a computer malfunction. I have owned a VSX since 1995 and the bulb in the switch only lit when the side lights/headlights were on. I thought this was really stupid as I had to switch the lights on just to see how of the suspension was set. I later found that this indicates a computer malfunction and when this was put right the light is on all the time, bright or dimmer according to setting. A year ago I had of a problem when the front suspension went rock-hard so I renewed the spheres. This made absolutely no difference. A trip to a Citroen dealer showed up the problem. A fuse was missing! Replacing the fuse corrected the both of the light and the ride. How the the heck it worked properly before I do not know!
Generally the ride isn't great on mine, but it's at its worst when something rocks the car. Each side of the car doesn't seem to have any independent movement at the back so a lumpy road can rock the car sharply from side to side. I can't believe this is normal as the ride in my father in laws Golf is better!
I'm going to see about replacing the anti-sink sphere, and check the links on the rear height corrector... see how I go.
I'm fairly sure that the hydractive switching is working at the back.... not so confiedent about the front.
Anyone buying a Xantia... Don't get hydractive. Nobody seems to understand it.
I'm going to see about replacing the anti-sink sphere, and check the links on the rear height corrector... see how I go.
I'm fairly sure that the hydractive switching is working at the back.... not so confiedent about the front.
Anyone buying a Xantia... Don't get hydractive. Nobody seems to understand it.
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tomsheppard
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Like all things Citroen there is nothing that would faze a Martian mechanic here. Check out the BX diy site in the links. There is a fair bit on hydractive suspension in the XM section. From my own recent experience, Citroens do take time to learn and like most fault tracing exercises, understanding begets success. The fact that it is still on sale suggests that Hydractive is a good idea but if you have little experience of Citroens then it becomes difficult to know what is right or wrong. Keep trying though, it is usually worth it.
It's not easy to compare conventional and hydropneumatic suspension, as the ride is different. I did a lot of comparisons, driving different road sections with various vehicles (GSA, BX, Xantia, Golf, Megan, Focus, A6...). I must say, I'm still not sure that it's worth to have a car with hydropneumatic suspension, bearing in mind various little problems, connected with it.
Hydropneumatic suspension is definitively better on the smooth road, with longer irregularities, like highways (if spheres are relatively new). It's because of the softer 'springs', and the car really floats over such a road.
But, on the road with shorter and sharper irregularities, ride can be somewhat harsh and in fact worse than in the normal car. There are two reasons.
a) because of the lower springs rates, damping rates are heigher than in the conventional cars. It's necessary, to avoid suspension 'bottoming' on bigger bumps. That's why some bumps are felt more than in conventional cars. Also, damping rate is constant over time, while conventional shocks gradually lose their efficiency, so their damping rate drops. Also, hydractive spheres have even higher damping rates than non-hydractive ones.
b) left and right suspension cylinders are hydraulically connected (except in hydractive suspension, hard mode), so whole body roll is taken by roll-bars. For that reason, they are thicker than in other cars. That are the reasons, why shaking from left to right is more noticable than in most conventional cars.
Hydropneumatic suspension is definitively better on the smooth road, with longer irregularities, like highways (if spheres are relatively new). It's because of the softer 'springs', and the car really floats over such a road.
But, on the road with shorter and sharper irregularities, ride can be somewhat harsh and in fact worse than in the normal car. There are two reasons.
a) because of the lower springs rates, damping rates are heigher than in the conventional cars. It's necessary, to avoid suspension 'bottoming' on bigger bumps. That's why some bumps are felt more than in conventional cars. Also, damping rate is constant over time, while conventional shocks gradually lose their efficiency, so their damping rate drops. Also, hydractive spheres have even higher damping rates than non-hydractive ones.
b) left and right suspension cylinders are hydraulically connected (except in hydractive suspension, hard mode), so whole body roll is taken by roll-bars. For that reason, they are thicker than in other cars. That are the reasons, why shaking from left to right is more noticable than in most conventional cars.