Bouncy C5 suspension even after new spheres!

[detheridge]

Hi folks,
I have a 2003 C5 Exclusive 2.0HDI with Hydractive suspension (only 4 spheres, unless I'm missing something!) no Sport setting on the centre console.
A few months ago my Satnav took me through a ford, which freaked out the ECU and set the car in wheel changing height. After a while it settled down but then reverted to what felt like intermediate height setting, even though it was set to normal ride. Part of the problem was traced to the front height sensor that was full of water. this was replaced. I topped up the LDS reservoir with a litre, as it was down at the bottom of the scale at the time.
After a while though, my car was riding like a Ford! A local garage checked it with a Lexia and found no problems. Lat week I had all four spheres replaced with new ones, but the ride (though slightly better than before) is nowhere near what it was. Still very bouncy and non Citroen like. I've topped up the LDS again (it was down to near the bottom of the indicator, and raised and lowered the suspension a few times, but still no smoothness.
There's no sign of any leak under the car, so where did the LDS go?
What am I missing here? Is there another sphere lurking somewhere, or is this an electrical problem? Is the system over pressurised and how do I remedy this?

Many thanks in advance,

David.

[xantia_v6]

It is important to check that the car is riding at the right height, the suspension won't work properly if it isn't.

It is also possible that the new spheres are the wrong type. If HA 3+ spheres are fitted to a HA 3 car, then the ride will be very firm.

[detheridge]

Thanks for the info. The spheres should be the right ones from the supplier I gave him the chassis number of the car. IIRC they're 55 on the front and 47 on the back.
Out of interest, how do you adjust the ride height?

[Stickyfinger]

Can I ask how you are reading the LDS level. Do you know why the level keeps falling ?

[GiveMeABreak]

Make sure you check the suspension on the 'LOW' setting. The levels should be between the Min and Max marks (a & b) as shown in the diagram below:

Next, I would check the height correctors are fully functional. They are electrical units connected to a mechanical linkage. Check the linkage (looks like a dog bone) is not rusted / seized. If these have been submerged in water then the electronics could be affected causing incorrect readings to be sent to the BSI.

The fact that you have said the car is raising and lowering itself (beyond normal automatic height correction adjustments) suggests that the car is not getting the correct height information - which again would point to a suspect height corecctor (s).

[Peter.N.]

My first C5 was a 2.2 which was hydractive and gave a good ride but I got rid of it on the grounds of poor fuel economy and replaced it with a 2.0.Hdi, the economy is much better but the ride is worse. I replaced all the spheres which improved it a little, I then found that the trailing arm bearings had failed and were seizing up, quite easy to tell, you still couldn't bounce the back, I replaced those but its still not anything like as good as the XM.

The chief problem is that on an uneven road it pitches from side to side quite severely, feels as though it would be better with the anti roll bar disconnected, on the motorway it rides fine but is certainly not as good as the 2.2, or the XM or the CX. I think maybe softer spheres are needed.

I tend to drive the 406 most of the time as it rides better over rough surfaces than the C5 and also handles much better.

Peter

[detheridge]

Stickyfinger: I was told that you read the level from the oblong panel on the side of the reservoir. It was nearly at the bottom so I filled it up to just below the top of the panel. There appears to have been no leakage from the cap as a result. Is this the wrong way? I don't know why the level keep falling. One self styled Cit expert 30 miles away thought it could be the pump on the way out, but then he looked incredulous when I said that my car had only 4 spheres. (Go figure, as they say).
Givemeabreak: thanks for the info. The level is now definitely between the min and max marks. Re the height correctors, would cleaning them out rectify things, or does the BSI need a reset as well?

Many thanks for all your help so far, folks.

[Stickyfinger]

As Marc says, level check on LOW setting.

Who changed the spheres ?
It is only after such work that the system needs topping up unless there is a leak. If there is a leak there will be drips under the car, pumps do not "use" LDS.

Your car will have more than 4 spheres btw, I think (?) it has 6, add two central regulator ones (control the firmness) to your list.

[xantia_v6]

Your car will have more than 4 spheres btw, I think (?) it has 6, add two central regulator ones (control the firmness) to your list.

Not if it is HA 3. Only HA 3+ have the extra spheres.

[GiveMeABreak]

The Mark 1 and Mark 2 facelift Hydractive 3 models have 4 spheres, the Hydractive 3+ on these models have 1 additional sphere at the front and 1 extra at the rear for firmness / stiffness regulation / accumulation.
The Mark 3 (X7) Hydractive 3+ C5s have 7 spheres, 2 additional at the rear and one at the front.

David - The easy way to tell without looking under the car is whether you have the SPORT button on the suspension height switch - which as you have said you don't, so Hydractive 3 on yours. Put it this way - 2-3 less spheres to worry about replacing!

A good squirt of Spray grease onto the linkage will help - but be careful about removing the height correctors - if you remove these, the car will likely need to be callibrated to get heights corrected - they can't just be bolted back on as a rule unless you are spot on with the location - so be warned.

[Stickyfinger]

Ha3 (+)....always thought they had 6 as standard.....cheers chaps

[GiveMeABreak]

7 in your case Alasdair - so an extra spring in your Zebedee!

[detheridge]

Many thanks for the additional info GiveMeABreak.
As I'm mechanically useless I rely on my very nice local garage here in Ludlow. The main guy there is a great Xantia fan - so I'll be passing on the info to help him do the job next week.

Just to clarify: are the height correct sensors different from the body height ones, or are they the same? My C5 seems to roll the entire car on bumps in the road, rather than each individual wheel absorbing bumps and dips, if you see what I mean. It feels like the suspension ECU thinks that the suspension is in intermediate height setting (up to 24mph on the display) and it feels the same stiffness in both the intermediate setting and the normal road setting.
If my friendly local mechanic takes the electrical connections off the height correctors, cleans them up (with IPA?), dries and replaces them with a good does of sealant, will that be problem solved? If the height correctors then need recalibrating, is that a Citroen garage specialist job, or what equipment do you need to do it? Will the suspension ECU need checking for errors?

[GiveMeABreak]

The body height sensors are the same as the height correctors in this context. There is one on the rear axle and one on the front. Your best bet is to lubricate the linkage first, as once the collar with the sensor is removed it will likely need recalibrating. Give the sensor a good squirt with contact cleaner (in place) and then do some gradual raising and lowering of the suspension. Remember if your mechanic is lifting the car off the ground on a hydraulic lift with the wheels hanging unsupported, you MUST remove the LDS reservoir cap first and replace it once the car is back on the ground on all wheels. Failure to do this can cause leaks in the system due to seals failing as a result of the pressure changes if you don't remove the cap and is must according to Citroen service.

Incidentally you won't have a separate suspension ECU in your C5, all this is done by the BSI. Only the C6 and V6 C5 X7s have a separate suspension ECU.

Back to the measuring, it is a bit of an Isaac Newton affair, requiring measurements to be taken in a certain way, using a formula to end up with some figures that are entered into the Lexia / Diagbox that then get translated into actual suspension values. So it is not as easy as sounds. This would only normally be done if the height correctors where replaced or other components affecting the suspension. Try cleaning up first and see how you go.

If your mech has a Lexia, this should also be your first port of call after the obvious lube / clean of the height correctors. This should give the reference height values and your actual values. If these are wildly out of tolerance then it will likely be the height corrector not sending the correct data.

[dnsey]

It sounds as though water might have got into the height sensors, so they are no longer returning reliable information.