Is this a Bullock dray on LHM?

alan s · Post by **alan s** » 20 Oct 2004, 03:11

A while back I bought a Xantia VSX 1995 model after several years of ownership of CXs and BXs and was told by some the ride was equal to a CX or at worst a BX. The nearest Xantia to me I would guess would be at least 2 hours drive away so I had nothing to compare it with, however, I find it rides more like something you would find being released at the Tokyo Motor Show; rough as guts in comparison to even a BX16V.
When parked, either with the engine running or not, I can push the rear down reasonably softly (about on par with the 16V) but the front is rock solid and I do mean solid. Like an early Ford Prefect with semi elliptic springs solid.[:0] Yet when driving, the ride is not like say a BX or CX with blown spheres; it's smooth yet harsh. I had the spheres tested on the front & found they were spot on and the accumlator doesn't click all that often but my guess is that I may have a flat anti-sink sphere and possibly an accumulator that's not all that far behind it. I'm basing this on the fact that the other day I parked the car at a shop and when I came out, not thinking, I knocked the handbrake off & pulled it out of gear as I was about to start & found the car rolling off down the driveway whereupon I hit the brake pedal & even after only being parked for around 5 minutes, there was no pressure there.
Could anyone confirm if they agree with my diagnsis or have any other suggestions and is this solid feeling front right or wrong?
Alan S

Post by **RichardW** » 20 Oct 2004, 13:10

Ah, VSX = hyperactive suspension...[8)]
The front certainly shouldn't be rock solid - my Xantia (non-hydractive) doesn't seem to have as much front travel as previous BXs, but it is still there. It sounds like yours might be stuck in 'hard' mode. Assume you had the front centre hydractive sphere checked as well? It should switch to hard mode after you stop the engine, and you should be able to feel a difference, so try pushing the front down engine running, then stop the engine wait or minute or so and try again. No difference suggests that it is not switching into soft mode, or the hydractive sphere is flat.
There is a known fault on hydractive cars whereby an o-ring in the hydractive block fails, causing rapid loss of system pressure when the engine is shut down - but you know about this, because the car dumps itself on the floor after about 1 minute....!
All the usual other checks apply as well - ride height, sticking struts etc

mseymour · Post by **mseymour** » 20 Oct 2004, 13:51

Alan I presume you know how to check what the hydractive computer is doing by using your radio on LW.

RichardR · Post by **RichardR** » 20 Oct 2004, 17:24

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by mseymour

Alan I presume you know how to check what the hydractive computer is doing by using your radio on LW.
<hr height="1" noshade id="quote"></blockquote id="quote">This doesn't apply to me at all, but I'm intrigued to hear how you use the radio to check the suspension! [?][:)]

Post by **RichardW** » 20 Oct 2004, 18:15

'Soft' mode is activated by energising a solenoid in the hydractive control block. To prevent burning out the solenoid, the ECU supplies a modulated signal. If you tune the radio to the appropriate area of the LW range (can't remember what it is) you can hear when the ECU is supplying the modulated signal for soft mode.
You can't tell if the block is working, or if the signal is getting to front, rear, both, or neither though as far as I am aware[:o)]

mseymour · Post by **mseymour** » 20 Oct 2004, 18:22

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by RichardW

'Soft' mode is activated by energising a solenoid in the hydractive control block. To prevent burning out the solenoid, the ECU supplies a modulated signal. If you tune the radio to the appropriate area of the LW range (can't remember what it is) you can hear when the ECU is supplying the modulated signal for soft mode.
You can't tell if the block is working, or if the signal is getting to front, rear, both, or neither though as far as I am aware[:o)]
<hr height="1" noshade id="quote"></blockquote id="quote">
Indeed. Basically it's anywhere on LW, towards the bottom end. If you find Radio 4 (uk) which is 198 and then go up and down a bit. With the suspension in soft mode there'll be a horrid and very loud tone. If you leave the doors closed with the ignition off this should stop after about 30 seconds.
While driving the interference should be there until you boot it or go round a corner quickly when it should stop momentarily. Pressing the sport switch will make it more likely to switch to hard mode.
I had problems with the front electrovalve on mine. The ecu was constantly switching in and out of hard mode and this was traced to the front solonoid being defective and taking too much current. Apparently it's pretty sensitive to solonoid failures. However the valves can jam up independently of the solonoid.

Panjandrum · Post by **Panjandrum** » 20 Oct 2004, 18:31

Very interesting.
Would this also tell me when my Activa is switching?

bernie · Post by **bernie** » 20 Oct 2004, 18:37

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by RichardR

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by mseymour

Alan I presume you know how to check what the hydractive computer is doing by using your radio on LW.
<hr height="1" noshade id="quote"></blockquote id="quote">This doesn't apply to me at all, but I'm intrigued to hear how you use the radio to check the suspension! [?][:)]
<hr height="1" noshade id="quote"></blockquote id="quote">
Apparently you tune your radio in to LW (the BBC light programe) until you hear the 1967 hit parade tune SUGAR SUGAR by the ARCHIES then drive off the nearest 100ft cliff to test your suspension[:D][:D][:D][:D][:D][:D][:D][:D][:D]

RichardR · Post by **RichardR** » 20 Oct 2004, 19:53

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by RichardW

'Soft' mode is activated by energising a solenoid in the hydractive control block. To prevent burning out the solenoid, the ECU supplies a modulated signal. If you tune the radio to the appropriate area of the LW range (can't remember what it is) you can hear when the ECU is supplying the modulated signal for soft mode.
You can't tell if the block is working, or if the signal is getting to front, rear, both, or neither though as far as I am aware[:o)]
<hr height="1" noshade id="quote"></blockquote id="quote">Ah, a back door solution! I had visions of something along the lines of switching to LW then pressing a particular button for 5 seconds to trigger the display on the stereo to give you a status report on the suspension! [:D]
That's what comes of growing up watching Knight Rider!

AndersDK · Post by **AndersDK** » 20 Oct 2004, 22:33

The Activa is no different - in the suspension part, as the Activa system is simply build on to an existing hydractive system.
Donno if the Activa anti-roll system is telling the Radio anything special when you corner [:)]
Try it - and tell us [8D]

allmond · Post by **allmond** » 20 Oct 2004, 23:49

I could never get the radio trick to work, but by putting the car in the garage and keeping VERY quiet, I could hear the solenoids. The noise stopping and starting coincided with the suspension going hard and soft.
Jamie

xantiav6 · Post by **xantiav6** » 21 Oct 2004, 12:09

The radio check worked well on my 1995 VSX, but on my 1997 V6 there is no noise from the suspension solenoids, so Citroen must have improved the RF filtering.
The other way to check the suspension operation is to wire a small light bulb across the solenoid. I attatched one to the wiper arm with cable ties. The light comes on at full brilliance for half a second when the suspension goes to soft mode, and then stays at half brilliance.
The performance of my hydroactive suspension improved markedly when the ride height was set correctly.
I think the roll bar stiffness contributes a lot to the comapiritively harsh ride.

alan s · Post by **alan s** » 22 Oct 2004, 03:16

Thanks for all the responses so far; I'll be taking a look in the next couple of weeks as soon as I have my 16V back on the road again following our sorting out of a major rear suspension rebuild caused by a "specialist" who was obviously a pastry cook impersonating a mechanic.
Any other thoughts greatly appreciated as I am slowly beginning to get a bit of an idea of what to expect of this car.
Overall, Ive been quite impressed with it so far apart from the "chiropractic" suspension.
Alan S

Stempy · Post by **Stempy** » 22 Oct 2004, 12:24

So, if the door has been opened, how long after it is closed again does the suspension revert to soft mode? I have noticed that when first driving away after getting in the car, the suspension seems to remain in hard mode for a short while. This leads me to assume that you should wait for the suspension to change back to soft after closing the door before doing the corner push suspension check.

mseymour · Post by **mseymour** » 22 Oct 2004, 13:48

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Stempy

So, if the door has been opened, how long after it is closed again does the suspension revert to soft mode? I have noticed that when first driving away after getting in the car, the suspension seems to remain in hard mode for a short while. This leads me to assume that you should wait for the suspension to change back to soft after closing the door before doing the corner push suspension check.
<hr height="1" noshade id="quote"></blockquote id="quote">
It's the other way round. The car reverts to hard mode, the valves have to open for soft mode. When you open a door the valves activate. Close the door and they switch off after about a minute, unless the ignition is on.