Rear Suspension Droops

[lyallp]

2010 C5 X7 2.0 HDI 160BHP.

 

have owned this car for some 8 months with few problems, we went away for 6 weeks, I tried to start it on our return, but the battery was in need of a charge, I disconnected the positive lead and charged the battery. Once charged and on reconnecting the positive lead there was a loud crack (electrical crack) from around the suspension pump. The car rose as normal and worked fine for a day or so.

 

Since then it has dropped at the rear every time I leave it. Prior to this the car remained level at all times.

 

The car now will sit up at the rear occasionally as if the rear is drooping whilst driving, its a bit disconcerting to say the least.

 

I booked it in with a dealer who diagnosed poor battery performance, so I replaced that and the garage "told" the car that a new one had been fitted, but they noted a few electrical voltage faults related to the suspension. They have just cleared them - and the car still drops.

 

Interestingly, once the rear has dropped if I unlock the car, it will return to normal height, lock the car  - and it will stay there all night.

 

Could the big relay by the suspension pump be at fault, or something more expensive. 

 

Anyone have any clues.

 

TIA

[paul.h]

Welcome to the forum.

 

It is surprising a Citroen dealer could not find anything wrong, maybe you need to try another one.

 

The rear suspension dropping overnight could be a sign of one of the struts leaking internally.

 

If the suspension did not go up at all it could be a sign the rear height sensor arm had broken since this is a common thing and a new arm is available from Citroen at low cost. Or maybe a problem with the valves in the pump but you could check the pump electrical connector is fastened on fully.

 

You could also check the suspension lds fluid level. With the suspension at the low height and the ignition key removed, remove the lds tank cap and the level should be just at the bottom of the filler neck strainer.

 

If you do go under the car use axle stands since if a height sensor is caught the suspension can quickly drop to a very low level. Before jacking the car up the suspension should be raised to the max height, this avoids possible suspension problems and is usually noted somewhere in the handbook.

[coastline taxis]

what happens when u use the hieght adjuster buttons inbetween the front seats

[Randombloke]

All Citroens with hydraulic suspension used to do this, but from the Xantia onwards they were fitted with an anti-sink valve at the rear.

 

Sounds like you have an anti-sink valve problem, if the C5 has one. 

[lyallp]

Thanks for the replies

 

The height adjusters in the centre console work correctly, also the one in the boot (its a tourer), I thought that buy exercising the suspension through the settings it might resolve it, but no.

 

What I can't understand is why does it stay up after I unlock the doors after it has sagged. if there is an anti sink valve in the system then it should work all the time, not selectively. 

[lyallp]

An update to this problem, the car spent some 2 days in a Citroen dealership, and after changing a "notchy" rear ride height sender they gave it back to me, but the problem persisted, another 2 days last week and they have diagnosed one of the electrovalves is passing fluid within the hydraulic control unit. They wanted to replace the unit, but I stopped them as its a massive cost (€1141+ VAT + fitting)

 

Can this unit be repaired? rather than replaced.

 

Thanks

[paul.h]

I think you would be better fitting a second hand pump (hydraulic unit, integrated bhi - different names for the same thing) rather than going for a new one at the price you have been quoted. I think it will need a diagnostic after fitting to configure it. How confident are you they are correct in the diagnosis of a faulty pump ?

[lyallp]

Thanks for the reply, I'm not confident that the garage has the correct diagnosis, they seem very unsure of the whole Hydraulic suspension setup. I am aware that if I fit one it will need setting up by Lexia, hoping to buy one soon itf I can figure out which one will suit a 2010 C5

[coastline taxis]

put a replacement anti sink valve on 1st before you buy anything else. if theres fluid leaking past a seal then you would notice the suspension taking ages to bring the car up to the correct height (which you havent mentioned)

[lyallp]

Thanks Coastline, but I thought the latest C5 X7 had an electrical anti sink valve within the pump control unit? I stand to be corrected though!!.

 

If it has a mechanical/electrical one separate from the unit, where will it be located?

[paul.h]

Depending on which country you are in, you can see the Citroen parts diagrams as a free service. Register on service.citroen as an other professional non emeregency services and as a member of the Citroen Owners Club. Then once on the site use your VIN (VIS) top left to find your car. Look under mechanical/suspension to see what is fitted on your car. http://service.citroen.com/do/changerParametres

[lyallp]

Thanks Paul H, I checked the Citroen website and found no replaceable items outside of the pump assy. I spoke to an independant Citroen dealer and subsequently booked the car in for him to have a look at, with the end result that he replaced the hydraulic pump with a new item he had in stock. and it has fixed the problem.

 

The price of the pump from him was a third of the price  of the same item from a main dealer.

 

The independent dealer is Mark Allen, and he is in county Wexford, Eire, he also has a significant cache of spare parts, new and secondhand.