C5 (56) 2.0D Rear sinking

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

richieboy007
Posts: 22
Joined: 31 Dec 2019, 12:32

C5 (56) 2.0D Rear sinking

Post by richieboy007 »

Hello
I was recommended to speak to you on this forum and reading through similar posts, it seems like you know what you are talking about!

I have a Citroen C5 2006. It's a 2.0 diesel and estate version. We got it recently and it has been a brilliant car.

I have no idea if it is related, but after going through some flood water, the back end sinks way more than it did before when left overnight, to the point the mudflaps are bending on the drive. I have had it checked over by a garage and they cannot see any leakage or damage underneath, nor could they see any issue with the spheres. It drives fine and levels out when you open the door - it just seems strange that it should start to sink way more than before all of a sudden.

I know there have been references to changes in temperature and whilst it is cold right now overnight, it's no more than recently or before

The local Citroen dealer wants £150 'diagnostic fee' to 'have a look at it', however I do not know what they are going to find that the garage couldn't, or are they likely to get a clue from connecting to the car and getting fault codes?

Any help before we throw money at this would be appreciated. I am about to get a tow bar fitted to it and would rather know it is all OK first and not going to be a problem

Thank you
Hell Razor5543
Donor 2021
Posts: 12013
Joined: 01 Apr 2012, 09:47
x 1513

Re: C5 (56) 2.0D Rear sinking

Post by Hell Razor5543 »

I wonder (but this is just wondering) if water has got into the rear height sensor? The dealership will connect up a specialist piece of equipment known as a DiagBox (it is possible to get clones of such). This can do a lot more than just read error codes. Their mechanics are trained on such equipment (information that Joe Public won't have access to).

Welcome to the Forum, by the way.
richieboy007
Posts: 22
Joined: 31 Dec 2019, 12:32

Re: C5 (56) 2.0D Rear sinking

Post by richieboy007 »

Thanks James... where abouts is the sensor located?
Gibbo2286
Donor 2020
Posts: 5529
Joined: 08 Jun 2011, 18:04
x 1260

Re: C5 (56) 2.0D Rear sinking

Post by Gibbo2286 »

Same model as mine by the look of it, mine had trouble with the front end and it was the height sensor, firstly there was copper corrosion in the connector which I cleaned off and it sorted the problem for a while then it stuck at the highest position so I took the sensor off and dismantled and cleaned up the circuit boards.

It's running ok now but I bought a new sensor to fit when the mood's right just in case.

The front and rear sensors are the same, part number 5273J4, got mine from EuroCarCare Ltd. Cost £43.90 all in.

I've not looked at how easy it is to get at the rear one but the front was just a ten minute job.
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26046
Joined: 15 Sep 2015, 19:38
x 2988

Re: C5 (56) 2.0D Rear sinking

Post by GiveMeABreak »

Highly unlikely to be the sensor. If it was the sensor, then it would not be self-levelling when driving - and you would be getting it riding too high or too low all the time. I say this as you have specifically mentioned that it raises fine when the door is opened. So that means the height corrector is working.

It is more likely to be the the hydraulic block (one of the exhaust ports controlled by the BHI) that stop the car sinking completely when the ignition is switched off. These can get jammed, and not fully closed, that allows the fluid to gradually seep back into the tank causing the slow sink (probably overnight).

I would try raising the car to it's highest setting, then lowest setting a few times to 'exercise' the electrovalves, then leave her on the lowest setting (on flat ground), and unscrew the LDS fluid tank cap, then with the engine running, very slowly turn the wheel lock to lock 5 times. Check the LDS fluid level is between the marks 'a' & 'b' as shown below. Top up the LDS if necessary (only between A and B and only when the car is on the lowest suspension setting)!
LDS C5 MK II.PNG
LDS C5 MK II.PNG (72.61 KiB) Viewed 101 times
Then return to normal setting, switch off and see if it sinks. This procedure will bleed the hydraulic system and get rid of any air locks and doesn't cost you anything. Failing this, further investigation may be necessary.

If the car rides too low generally - then you may well have a rear height corrector problem - but this should be evident if raising or lowering the car and the rear is not raising and lowering as commanded (it should be level with the front). Don't get underneath the vehicle without it being independently supported if you suspect a height corrector problem, as it may just collapse rapidly without notice and can crush you.
richieboy007
Posts: 22
Joined: 31 Dec 2019, 12:32

Re: C5 (56) 2.0D Rear sinking

Post by richieboy007 »

This is awesome, thank you Marc. I will try this. Very much appreciated
richieboy007
Posts: 22
Joined: 31 Dec 2019, 12:32

Re: C5 (56) 2.0D Rear sinking

Post by richieboy007 »

As the garage have been checking and testing it this morning, running it to full and then minimum height several times, I will leave it for the moment and see what it does overnight. Perhaps this could have cleared the hydraulic block (fingers crossed) and all will be OK for the moment, and I can get this replaced at my leisure.

Thank you again, I will let you know what happens
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26046
Joined: 15 Sep 2015, 19:38
x 2988

Re: C5 (56) 2.0D Rear sinking

Post by GiveMeABreak »

Ok, I forgot to mention too - remember this vehicle uses LDS fluid (the orangey coloured one - not the green LHM fluid on older hydraulic Citroen like the Xantia and XM).
richieboy007
Posts: 22
Joined: 31 Dec 2019, 12:32

Re: C5 (56) 2.0D Rear sinking

Post by richieboy007 »

GiveMeABreak wrote:
31 Dec 2019, 14:07
Ok, I forgot to mention too - remember this vehicle uses LDS fluid (the orangey coloured one - not the green LHM fluid on older hydraulic Citroen like the Xantia and XM).
:-D