c5 Suspension and swirl valves

[hayabusa1300r]

Morning everyone,

I've thought a while my C5 2001 Hdi Hydractive + is very loose at motorway speeds, yesterday I notice after a 100 mile run when I stopped the suspension was quite high, ie 1st step up after normal if you use the "button" in the centre console? But I hadn't touched it. Seconds after I stop and stood next to the car it dropped a little to what I would call the normal ride height. The car wasn't loaded at all, and the pump seems to function normally. I use the "sport" setting sometimes but tbh it doesn't seem to make much of a differenance, if anything the car wanders more at 70+. I apologise in advance for asking so many questions on this forum, but for those that have read will know I've "inherited" this car from my brother and am trying hard to bring it back from the brink, anything I do I post to pass on what I've learnt, and you know what I actually like the car. I know the 2.2 isn't as economical, but coming from a guy that's had 2 new Mondeo estates in the last 4 years I can categorically say when on song the 2.2 is such an ace engine, its like double cream its that's smooth and effortless low down I love it.
Swirl valves, I changed the actuator, and its pokier low down ie below 2100rpm, as well as much better on fuel, I read 1 post that said when knackered it screws the fueling up, but I did not expect the running to be better below 2100 but above that? I'm not complaining and for 23 quid was a no brainer. How many miles should I expect from a tank of mixed driving?

cheers John

[myglaren]

Don't be concerned at asking lots of questions John. It is what the forum is intended for after all and as a new user you are bound to have many.
We all learn from them so it benefits everyone.

If the car is wandering it may be time to check the suspension bushes and ball joints, also the tyres.

As for being high after a motorway run, odd but then so are C5s

I did a 220 mile run from Huntingdon yesterday and when I parked the rear end dropped a couple of inches*. There was about half a mile of surface roads after the motorway though - I live right on the A1!

*Which is somewhat contradictory as when at motorway speeds it should drop an inch to reduce drag - I cannot say that I have ever observed this phenomenon.

Others will no doubt fill in the blanks and I haven't a clue regarding swirl valves.

[hayabusa1300r]

ta, thank you!

[GiveMeABreak]

Can't help you with the swirl valves, but regarding the suspension, as Steve says, it is designed to lower up to 15mm at the front and 11mm at the rear at motorway speeds to increase economy and stability and raises by up to 13mm on poorer surfaces to improve ground clearance. Now the sort of height variations you have mentioned don't seem at all right.

I would initially suggest that the front and rear height correctors may need a bit of a lube. Although these are potentiometers, they are connected to the anti roll bars by a mechanical dog bone. The bone joint can become seized, so a good helping of WD40 will help this - but don't take it off or adjust anything - as doing so will put the suspension settings out of kilter - that is the next step! The front height sensor is attached to the front anti roll bar behind the drive shafts.

Warning Just don't get under the vehicle unless it is is supported independently from the suspension alone - especially if you suspect the suspension is faulty as it can depressurise, causing the vehicle to lower and crush you! Get it over a pit or on a ramp or stands before getting under it.

See how you go with this first of all - it will take some time for the oil to penetrate - but these height correctors are really exposed to the elements, so it might take a while to penetrate.

[myglaren]

Try doing a lot of Citroebics to flex the height corrector linkages as much as possible.

Although this doesn't have the same effect as 'proper' Citroen hydraulic systems I do it often to - as said - flex the linkages but also to use normally unused sections of the rams - normal usage only covers quite a small section of the total length.
Also to 'exercise' the pump/motor.
As the motor only runs for a very short time each time a height adjustment is made it never gets warm. From reading the forums the most common cause of pump/motor failure appears to be corrosion of the motor electrics.
Running it often and extended (hopefully) dispels moisture and reduces the chances of corrosion.
Of course, a squirt of WD40 would probably do the same but doesn't include the enjoyment of seeing the disbeliefe on the faces of drivers of adjacent and following cars while waiting at the lights

Probably dumb luck be the suspension has never been a problem on either of my C5s.