Xantia Hydractive Cork-Screwing...

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dragen
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Re: Xantia Hydractive Cork-Screwing...

Post by dragen »

Hi Chris, thanks * heaps* for the detailed answer, fairly certain I'm not getting a front end click, but will check out in detail later, including voltage supply. May see if the wrecker has a second unit there also... Will post with how I get on... :-)

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xantia_v6
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Re: Xantia Hydractive Cork-Screwing...

Post by xantia_v6 »

If the hydractive sphere is the wrong spec, or faulty, it can cause similar symptoms, so it would be a good idea to check it by swapping with another sphere. The main accumulator sphere is close enough in pressure to do this test, or maybe your old accumulator or front hydractive sphere if you are confident that one of them is OK.

dragen
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Re: Xantia Hydractive Cork-Screwing...

Post by dragen »

Definitely rear clicking, but none in the front end. Replacement sphere is new and looked good and of correct labelling and spec to website, plus old one hadn't burst. Will get into voltage checks etc in the days ahead.

I suspect the 'corkscrewing' in corners would be the difference in behaviour and weight transfer at each end as the car loads up in corners. ie the hard nose stays flat, while the soft tail rolls out, effectively oversteering the car slightly and tucking the nose towards the apex, before it potentially switches to firm. Causing the snaking through a corner.. Thoughts?

Also wondered if intermittent reading at the rec counter also effects the data that the hydractive is using to select hard/soft. As in, if it isn't receiving rpm will it stay soft more often?

Cheers... ! :-)

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xantia_v6
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Re: Xantia Hydractive Cork-Screwing...

Post by xantia_v6 »

The hydractive ECU does not get the RPM signal, so that is not likely to be the problem.

Check the flow rate from the rubber return line of the front HA valve. There should be no flow inn firm mode and not more than an occasion drip in soft mode, with a spurt when the mode changes.

Note that you need to block off the end of the hose or your will dump a lot of LHM from the regulator return.

dragen
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Re: Xantia Hydractive Cork-Screwing...

Post by dragen »

Will do that check. Gotta say, the firm on the twisting tight roads I have on the way home (lots of 50-80km/hr 3rd gear stuff) feels good with that strictly hard mode nose... be nice to really be able to switch between hard and soft, ie no soft mode in 'sport' as the early models used to have, if I read right... ?

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Re: Xantia Hydractive Cork-Screwing...

Post by aerodynamica »

Also, on some Hydractive Xantias you can open the bonnet and reach down to touch the front HA regultor block. On mine you can reach it with the intercooler pipe disconnected. I can feel the thing click.

I must say that the more I read of your 'corkscrewing' the more I think mine does the same thing. I've been getting a sort of wayward feeling as though there's a 'looseness' to the wheels. It feels mostly from the rear and is only really on occasion that I properly notice it. I actually suspected the back subframe was loose but there's no noises, no evidence of that. It might be caused by my suspected bad front tracking that I still haven't had checked.... also rear arm bearings done 16months ago, front arm bushes in Feb, strut tops last September, checked the wheel bearings and no movement found in the track rods. I'd describe my issue similarly but perhaps more that there feels at times to be some diagonal jerk and sometimes the front doesn't seem to have softened as much as the rear. And a general feeling of waywardness. Actually feels worst at lower speeds.

I have never done the 'diodes modification' though. All 7 spheres were replaced last Nov-December. Not sure if it's the same problem as yours.

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Re: Xantia Hydractive Cork-Screwing...

Post by aerodynamica »

dragen wrote:
29 May 2019, 09:56
Will do that check. Gotta say, the firm on the twisting tight roads I have on the way home (lots of 50-80km/hr 3rd gear stuff) feels good with that strictly hard mode nose... be nice to really be able to switch between hard and soft, ie no soft mode in 'sport' as the early models used to have, if I read right... ?



You can actually do that with Hydractive 2 if you fit a relay next to the ECU and have the ECU's 12v supply switched by the normally closed relay. I did this with a relay powered by a switch on the dashboard (I repurposed the switch for locking out the rear elec windows)

It cuts the 12v to the ECU when you press the switch as though the ignition was turned off.

My solution isn't perfect though because after you press the switch it stays in soft for 30 seconds before turning off the electrovalves just as it does after you switch off and lock the doors.

Could make a refined version with a double relay that also cuts the ECU earth at the same time then it would immediately turn off the ECU and hence the electrovalves giving immediate hard suspension. Just a project if you're handy with a bit of wiring and soldering but it does work!

dragen
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Re: Xantia Hydractive Cork-Screwing...

Post by dragen »

Sorry Aerodynamica, I forgot to reply to that one. Definetly tempted by that approach with a relay and being able to fully switch out the soft mode for how tight the first half hour of driving whenever we go anywhere...

I just had a few things to do for the 6-monthly 'Warrant of Fitness' we have here in NZ:
* Intermittantly faulty headlight, took the nose off, removed an old block of relays related to a horn siren and an awful tangle of wires and relays that someone had spliced into the headlights at some point. Replaced the headlights with ones off another car, with good shiny reflectors, replaced indicators, etc. Turned out to be a faulty earth causing problems so put a new one in.
* Tidied up a heap of cabling and put new plastic flexi protector around alot of them in the engine bay.

So time to get back to tweaks and improvements. On the list:
* Remove the Intercooler and Radiator and give a good reverse blast with the compressor (can see lots of seeds and insect corpses in there).
* Remove the AC radiator (as removed compressor a year back).
* Pretty sure haven't replaced the thermostat on this car, so a new one on the way.
* Replace the injector return lines as there is a bit of seep around these and the injector pump (anyone know what diameter they are... ? )
* Check if the fog lights fault is also a bad earth and get them operational.
* Have some 9000 lumen LED H1 bulbs on the way, will try those in the low beam units, see if that gives an improvement to night vision.
* Get onto sourcing and soldering in the diode for the faulty front electro valve, and for the rear (any source suggestions?)
* Possibly do this relay to switch in and out the suspension ECU
* See if the airbag that have from a parts car can be fitted as this one seems to have had its removed.
* Give the carpets a shampoo and clean!

Should keep me entertained! Just hope the farm bike, quad, tractor, pickup and bmw behave while all this is happening... ! :-)

dragen
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Re: Xantia Hydractive Cork-Screwing...

Post by dragen »

Would this diode from element 14 be suitable... ?

https://sg.element14.com/microsemi/60s4 ... /dp/365889

Any Standard 6A 400V Diode will do, doesn't need to be a 'recovery' type...?

dragen
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Re: Xantia Hydractive Cork-Screwing...

Post by dragen »

Howdy team

Finally got back on the frenchie, got diode's sent via trademe and soldered them in last night. As can see I went for a separate Earth from outside of the ECU box, as I had a faulty earth issue with the headlights.

Suspension is now running smoothly again, but I still have that sideways skip/slide/corkscrew, it almost feels like have a flat tyre on left-hand turn-in, I have popped that RH rear wheel off and inspecting the rear sub-frame. Currently considering:
* air locks in the RH rear hydraulics, requiring bleeding...
* I am assuming if bubbles in the hydraulic fluid itself then all points would be affected, rather than consistently one side of the car
* returning to something physical, rear sub-mounts, bearings, ball-joints at the front end. All have been recently inspected for the Warrant of Fitness however.

Again, open to suggestions! :-)

Cheers
- Simon
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sparksie
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Re: Xantia Hydractive Cork-Screwing...

Post by sparksie »

Sounds a bit like wheel bearing, or axle bearing issues.
Have a look at the camber on the rear wheels and make sure it can't change under lateral loading.
If a rear wheel suddenly goes to positive camber half way around a bend, the result will be a snap oversteer.

dragen
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Re: Xantia Hydractive Cork-Screwing...

Post by dragen »

Hi Sparksie

Thanks for that, I was thinking something along those lines. When my BX rear swing-arm bearings got worn the camber allowed the wheel to touch the inboard guard under compression, but I haven't yet seen any camber on the Xantia, I am also on quite wide rims (215/45R17) so would expect contact... maybe. But I'll certainly check it out and report back.

Cheers
- Simon

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white exec
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Re: Xantia Hydractive Cork-Screwing...

Post by white exec »

If any of your local MoT depots have under-wheel wobble plates, it might be worth asking if they'd test each wheel for movement.

aerodynamica
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Re: Xantia Hydractive Cork-Screwing...

Post by aerodynamica »

Simon, wishing you all the best in sorting this. Increasingly I think my Hydractive Xantia is also doing the same thing. I feel that there's some weird imbalance between the two sides as though one corner of the car occasionally goes firm on its own (?) I have it in my mind that in Soft Mode the fluid cross flow is blocked by a neat little two way check valve that blocks the flow in one direction or the other (side to side) to help stop body roll. The second function is that this valve's action is overridden by the in flow from the height corrector (to ensure inflow is equal to each side) Is it possible (heard of) for this little set up to go wrong?

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Re: Xantia Hydractive Cork-Screwing...

Post by aerodynamica »

sparksie wrote:
21 Jul 2019, 02:04
Sounds a bit like wheel bearing, or axle bearing issues.
Have a look at the camber on the rear wheels and make sure it can't change under lateral loading.
If a rear wheel suddenly goes to positive camber half way around a bend, the result will be a snap oversteer.

That's interesting - I wonder if that's my issue? My rear arm bearings were done about 2 years ago and in the last 8 months the front arm bushings all replaced, tracking adjusted, new strut tops, brakes serviced and I recently replaced a front ball joint (that only lasted 2 years....)

One thing: I am running alternative wheels - 16" Peugeot Nimrods. they have tyres that are of a size that matched the same circumference as the correct Xantia wheel/tyre so, quite low profile. I also have 15mm spacers on the rear and now 3mm spacers on the front - the front track still has a similar differential to the rear as was original. I wonder if these spacers at he rear are causing a problem with the way the weight transfers diagonally..? I mean the 15mm would give a tiny mechanical advantage between the suspension of two diagonal wheels but I wouldn't have thought it would be much..

Just a though as the OP said he has wider wheels as well..