My new XM

Thanks for tip on CC - that's two things for me to check!

Have to disagree about the effect of opening a door. Your reasoning sounds sensible to me, but my Hydractive 2 document says otherwise:

"The door and boot open sensors will override the hard setting of the suspension as long as the vehicle
speed is below 24 km/h. The suspension will consequently go into soft mode whenever any door or the boot
is opened, and will remain in soft mode for 30 seconds after all the doors are closed if the vehicle speed
remains below 24 km/h. As long as the vehicle maintains a speed of at least 24km/h, normal rules apply,
and will continue to apply even if the doors remain open. It is important to note that the suspension will go
into soft mode even with the ignition switch turned off. Should the doors remain open with the ignition switch
in the off position, the suspension soft setting will be subjected to a 10 minute timeout to avoid draining the
battery, as the soft setting requires the electric valves to be energized."

You'll be pleased to know that I did not exceed 24km/h while doing the "door open" test.

This comes from a PDF that appears to be part of a larger document. The heading is "Hydractive 2 suspension system". I think John (JBN) might have sent it to me. I am assuming that Hydractive 2 is the same for an XM as for a Xantia.

Still haven't taken to for a drive to see whether hard mode will unlock once on the road - rain today, so she (?- not sure - might be male) stayed inside, warm & dry.

Cheers

Alec
 
I fitted a "tell tale" led in a visible spot, that allows me to monitor the operation of the electro valve whilst driving. Mine is a series 1, and my electro valve doesn't sing. I can hear it click in & out, but that's all. The operation of the hydractive defaults to firm if it encounters any dud sensors. It has a self diagnostic function, which you can manually extract fault codes with a simple led blink reader.
Also, low hydraulic line pressure will imede the shift to soft, or shift it back to hard, even though the electro valve is energised.
Search "pressure regulator tuning"on the UK XM forum. There's a good blurb on there about it.

Very good system, but they are old now & no one knows how all this stuff works, so you have to start from scratch.

Sent from my Pixel 2 XL using aussiefrogs mobile app
 
I can see I have a steep learning curve ahead of me... Thanks for your insights Motorgnome. I obviously need to keep the possibility of a dud sensor in mind, however at present the tip about low hydraulic pressure might be the clue I was looking for.

Now I realised that I hadn't tried starting the car since noticing that the suspension seemed to be locked in hard. Starting it did in fact allow it to switch to soft mode, as soon as the beeping stopped! It will hold the soft mode for 30 seconds after I stop the engine and exit the car (doors closed), but then refuse to do it again - sounds like a flat accumulator, so looks like I'm back to the need for new spheres all round.

I'm very pleased to have read recently (must have been on UK XM forum) that IFHS supply "fresh" spheres that arrive with the proper gas pressures. Just as well, as I have no way of testing/regassing them.

Also pleased to have 'solved' this issue - however I just observed something else I don't understand...

When I switch off the car and exit, the suspension is definitely in soft mode - and if I do nothing after closing the door, it switches to hard mode after 30 seconds (as it should). However the electrovalve sound is very muted - in fact I am certain that only the rear electrovalve is buzzing. However if I then reopen the door, the front electrovalve activates and the buzzing becomes much louder! If I do that before the initial 30 seconds is up, suspension stays soft much longer. Anyway, not too stressed about it, as front suspension behaviour seems normal (won't know about rear until new spheres go on) - just puzzled!!!

Cheers

Alec
 
My understanding of the different hydractive systems in XMs is that in the earlier version hard mode isolated the centre spheres and soft mode left them in the circuit. In the later version the centre spheres were not permanently isolated but in hard mode the trigger points for isolating them (e.g. cornering, sudden braking) were easier to reach.

So with an early XM I could run with CX spheres on the corners and lock the centre spheres out of circuit and have a car that behaved quite reasonably (though with the centre spheres in the circuit it was awfully wallowy). But with a later XM that trick would not be as effective.

Roger
 
Motorgnome said:
I fitted a "tell tale" led in a visible spot, that allows me to monitor the operation of the electro valve whilst driving. Mine is a series 1, and my electro valve doesn't sing. I can hear it click in & out, but that's all. The operation of the hydractive defaults to firm if it encounters any dud sensors. It has a self diagnostic function, which you can manually extract fault codes with a simple led blink reader.
Also, low hydraulic line pressure will imede the shift to soft, or shift it back to hard, even though the electro valve is energised.
Search "pressure regulator tuning"on the UK XM forum. There's a good blurb on there about it.

Very good system, but they are old now & no one knows how all this stuff works, so you have to start from scratch.

Sent from my Pixel 2 XL using aussiefrogs mobile app
Click to expand...

It probably needs diodes fitted, They should buzz. a constant 12volt feed would fry them no doubt.
 
First step is to eliminate any dead spheres and check they are approximately the correct type. The two regulator spheres are like accumulators without a damper, but at different pressures, so you can use a 6Bar accumulator at the front and a partly flat one at the back as reasonable substitutes. The ES9 uses different sphere pressures at the front vs the PRV - 45Bar mains vs 50Bar for PRV. The regulator spheres are 70 or 75 at the front. In practice, there is a range that the spheres are OK, so it's not so critical. The obvious difference is the size of the hole in the damper being, offhand, about 1.2mm for non-Hydractive and more like 0.8mm for a Hydractive. I have used non-Hydractive Xantia spheres on an XM and the ride is not uncontrolled at town speeds. You could try swapping some known good Xantia spheres as a test.

The other issue you have to look at is the Hydractive control system. There are a number of sensors for body movement and pedal position etc., but these rarely give trouble. However, it has no way of knowing the sphere pressures, so effectively operates independently unless the motion of the car somehow triggers it. The stiffness or regulator sphere blocks are like hydraulic relays with an electrovalve. Be aware that they are not all the same as early units are different to late units. There are actually dampers as you would find in a sphere inside these parts. I've had the o-ring for the cap nut that retains the spool valve split and leak badly. There is a gauze strainer on the end of the valve and it can be perforated if you poke a pick too far inside the threaded port opposite.

If you hear the electrovalve click in, hold for a few seconds and then out again and do this repeatedly, then it is likely there is a fault with one of both of them. The ECU will deactivate both electrovalves if there is a fault detected in one. It seems the usual issue is the diode encapsulated in the brown plastic winding part of each valve. This is why people advocate fitting external diodes. It does make a difference as fitting these to a car with a ruptured rear sphere masked the problem which was very obvious without the external diodes. You can buy that kit sold via eBay or make up your own if you follow this link:
https://translate.google.com/transl...araturanleitung-dioden-hydractive-citroen-xm/
For convenience you can fit the diodes near the ECU, but you need to identify the correct wires as they enter the socket. I have the pin references somewhere and will look later.
 
Roger Wilkinson said:
My understanding of the different hydractive systems in XMs is that in the earlier version hard mode isolated the centre spheres and soft mode left them in the circuit. In the later version the centre spheres were not permanently isolated but in hard mode the trigger points for isolating them (e.g. cornering, sudden braking) were easier to reach.

So with an early XM I could run with CX spheres on the corners and lock the centre spheres out of circuit and have a car that behaved quite reasonably (though with the centre spheres in the circuit it was awfully wallowy). But with a later XM that trick would not be as effective.

Roger
Click to expand...

H1 and H2 are different and parts are not interchangeable. The third sphere is always switched in for soft mode and out for hard mode. However, H1 apparently switches the third sphere out permanently in 'Sport' mode but controls it in 'Auto' mode, switching between soft and hard modes. H2 has different logic and also uses the third sphere in both 'Normal' and 'sport' modes, switching it in/out as determined by the logic for each mode. The roll limiting differs between H1 and H2 and you are probably aware the corner spheres are different for H1 and H2. Fitting the early corner spheres to a late car gives a hard ride for this reason.
 
Thanks David - hopefully new spheres (on the way from IFHS - I really don't have a supply of known good spares) will finally let us experience true Citroen ride comfort.

Mike (previous owner) certainly did his research, and did his best to care for this car (including purchasing 60 litres of LT71141!!!). He has already fitted an e-crofting diode kit, which no doubt contributes to the (very loud) buzzing from the electrovalves - especially the front one! Unfortunately the spheres that Jason regassed for him are not holding up very well.

How hard should the front be when the suspension is in hard mode? At the moment I cannot detect any front suspension movement at all when at rest (pushing on one corner at the front or using a front door as a lever to rock the car side to side). When we drove it with the front stuck in hard, it was like driving with the suspension on max height - just no travel at all. Am I right that this likely indicates that both front suspension spheres are flat, and that only the hydractive sphere is providing some comfort?

Cheers

Alec
 
Thanks - unfortunately can't get the 2nd to display - seems to be a fault with the PDF.

Cheers

Alec
 
Armidillo said:
Thanks - unfortunately can't get the 2nd to display - seems to be a fault with the PDF.

Cheers

Alec
Click to expand...

Second link works here, seems it covers Citroën XM 2.5 Turbo D VSX?

Cheers
Chris
 
ES9J4 V6 is there too. There are 116 pages of diagrams. PDF 1.4; the fonts are embedded, so it should display easily.
 
It opens for me. An ordinary pdf.

I just downloaded the XM2 file again, using both Vivaldi and the downloader wget. There was a 301 moved redirection. It also opens properly.

Try copying the URL into a downloader. The German site is devoted to the XM.

Try here too- http://www.xm-ig.de/

ps both files are about 55 MB
 
Last edited:
OK - noticed that if mouse pointer hovered anywhere near the two parts catalogues, both would be highlighted. Seems that the links are concatenated on the page. By separately copying and pasting each one into the address bar of a web browser, I was able to access both catalogs - so thanks v. much - good old microfiche eh!

Now to the earlier problem (post #51, 2nd link). If I right-click, and choose "Open in new tab", the browser attempts to open this link
"http://citroen.tramontana.co.hu/en/system/files/circuit_diagram.pdf", but only ever displays a black page.

However, if I copy and paste the link, I get to the tramontana site, but it shows this message:
[h=1]"404 This particular URL was not found but it is somewhere here, probably."[/h]This is apparently because what I copied was this - "http://citroen.tramontana.co.hu/en/s...it_diagram.pdf" - and the 3 dots don't resolve into anything useful. However, it shows me the menu, and tags, which give me access to the whole site - very interesting, thanks.

Cheers

Alec
 
Well it;s a browser thing. I just downloaded them all,including the diagrams, by copying and pasting into a downloader. My dots resolved.


Glad you found them interesting.
 
Right, time for a new chapter.While waiting for a few bits and bobs, thought I'd have a look at spark plugs. Shouldn't be any problems - plenty of power and excellent fuel economy...

Got the coil pack off OK, then - Oh Dear!


attachment.php


Counting from timing belt, first well has a little oil, 2nd has quite a lot, and third is flooded. In the RH well the oil is high on the spark plug tube on the outside, and up to the top of the plug insulator inside the tube. Is this the result of cam box leaks? I suppose the only other option would be a major spill while topping up the oil, but this is not clean oil straight from the bottle...

Suppose I'd better get the inlet manifold off to see how bad the other bank is.

Sigh... - Mike (previous owner) did warn that cam box leaks still weren't fully fixed, but I was only thinking of external leaks, and it doesn't look too bad at all on the outside of the engine.

Someone mentioned that someone (in England?) is producing gaskets for these cam boxes - does anyone know about this? I guess I should put this in Pug forum as well, as D8 406s use this engine.

Cheers

Alec
 

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