C5 Oversteer

[MaxPrimal]

Hi Guys.

I got my 2002 C2 2.0 16V Exclusive Auto just before xmas. When I got it it had a couple of tyres near the limit. I noticed the car felt like it wanted to over steer a little at times, especially when approaching full lock or on tight turns. I put this down to the dodgy tyres. Yesterday after noticing one was like a slick I got Kwik-Fit to change the two fronts (which is a joke as they took two hours to change them after 3 of their "mechanics" spent 2 mins trying to fit the adapter to their wheel balancing machine to take my alloys!). They also did the tracking which was out (2.2mm toed outwards when it is supposed to be 1mm in due to being front wheel drive?) Anyhow, Tyres on, lots of grip - yay!

But the car still seems to want to over steer at times. To go to and from work I have to make a u-turn at one point to get on/off the motorway junction near where I work, as you make the turn which has to start at about 1/2 lock and end up at full lock to get into work and about 3/4 away from work, you feel the car want to snap and over steer into the turn.

What are the likely causes and which ones are easy to see? I am hoping it is not a steering rack as I know on other cars these are not cheap (£200-£500). But what you think?

Any ideas are welcomed

[Mandrake]

Were all four tyres poor but you only replaced the fronts ? That would tend to worsen any oversteer as oversteer in a front wheel drive car like the C5 is usually only possible if either the rear tyres have poor grip, or the rear suspension is unusually stiff.

So as well as the rear tyres, check the rear suspension is nice and soft. If the spheres are shot or the rear suspension arm bearings are shot the rear will wander wide on rough surfaces as it can't follow the road to grip properly.

By the way Kwik-fit are misinformed. A C5 needs toe out, just like a Xantia, not toe in!

According to Citroen data the C5 (Mk 1) wheel tracking is minus 0 degrees 13 minutes +/- 0 degrees 13 minutes. (A minus figure is toe out)

In other words the acceptable range is between parallel and 0 degrees 26 minutes toed OUT. They don't quote a figure in mm, but comparing it to the Xantia data (which is almost identical in angle) that is pretty close to 0 to 3mm toe out. So ideal tracking is 1.5 mm toe out same as a Xantia.

Take it back and get them to reset the tracking to what it should be. I doubt this error would cause oversteer, but it would certainly make the steering feel a bit strange.

PS I feel your pain with the wheel balancing, it took National 3 tries to balance my center-less alloys Xantia rims, with the first two attempts ludicrously far out.

[MaxPrimal]

Thanks for the heads up on the tracking. I will call them tomorrow and pick them up on it. I thought they said mm, maybe it was degrees. Who knows, it means next to bugger all to me in truth.

They said that as a front wheel drive accelerates the wheels naturally toe out - hence the tracking is set inwards to make the wheels align at speed. I have not had a front wheel drive car in over 10 years so I have no idea...

Yeah I only had the two front tyres done, the rears are fine with loads of tread on them so they did not need replacing (thankfully). I will bounce the suspension over the weekend and see what it does. It does squeak a bit but seems to be okay to me. They say the offer a free suspension check - wonder if they are worth a risk in asking them to check it while they correct the tracking?

Thanks for the heads up and ideas. At least I have something to consider.

Max

[Mandrake]

Whether its mm or degrees toe in is still wrong, it should be toe out... The original 2.2mm toe out that you say it had before is within spec although that much toe out will wear the tyres a bit quicker and make the self centring of the steering stronger, I would go with 1.5mm.

Whether a car needs toe in or toe out is really nothing to do with it being front wheel drive or rear wheel drive, it's to do with the geometry of the front suspension, different geometries and configurations better suit toe in or toe out. Some front wheel drive cars are toe in, some are toe out.

For example older Citroens with double wishbone front suspension (GS & CX) had toe in, recent Citroen's with McPherson struts I believe are all toe out, certainly the Xantia and C5 are.

When you do the bounce test make sure the engine is idling, especially if the car has Hydractive 3+. It should be really soft, and a lot softer than the front suspension - you should be able to press the rear suspension down to the bump stop with one arm, if it feels like normal steel springs its not working properly.

Would I let Kwik-fit play around with Citroen suspension ? No chance!

[Northern_Mike]

I found my C5 a bit oversteery when I first had it, but it was just my imagination. The steering was lighter and quicker than what I had before, so it felt it was going to oversteer, it never did though.

Please, please please let Kwik-fit check your suspension if you have a little time to waste - then post the results here and we can all have a good laugh.

Many, many, years ago they told my brother his BX needed new shock absorbers because the ones on it were knackered..

[Mandrake]

Good point, does it actually let go at the rear, or are you just being fooled by the passive rear steering ?

[MaxPrimal]

Yeah I thought that about the suspension and Kwik-fit but I was impressed to see they did raise my suspension before jacking the car up - so someone had more brains than I thought!

No idea what Hydractive3+ is. All I know is my suspension has 3 buttons on the centre console: Up, Down and "Sport" and the multi-function display tells me things when I push the buttons. I may test it when I get home as I park in a level car park.

Yeah that sounds like a plan... I'll see how it feels so you may get another question on this

[MaxPrimal]

hold those thoughts. Got to get the wife from work... I'll be back with a question in 20 mins

[Mandrake]

If you have a sport button for the suspension its Hydractive 3+. What that means is the suspension has two modes - firm and soft.

While driving the suspension will try to stay in soft mode most of the time, but when you corner, brake or accelerate beyond certain thresholds the suspension (both front and rear) switches automatically to the firm mode where springing and damping are both beefed up to minimize body roll and improve handling. It's fairly transparent if you don't know what to look for but when you know how the system works you can notice the suspension getting firmer and softer while driving.

This switching between soft and firm happens regardless of the sport button setting, however in the sport mode it switches to firm far more readily thus the handling feels more sporty.

The main point is that the bounce test needs to be done with the suspension in the soft mode which it will be with the engine idling, but not if the car is parked with the engine off. With the engine off for a minute or so (and all doors closed) it should switch into firm mode and you should notice the suspension is much stiffer when bounced, with hardly any movement.

[Hell Razor5543]

MaxPrimal, where are you based? If you are in the Reading area, the Kwik Fit in Wokingham could be a safe place to go for the suspension, as one of the MOT guys is familiar with Citroens (he sold me my first car, a BX). I know he used to have a CX estate (series 2), and a BX estate, and he knew what he was doing to maintain them.

[Northern_Mike]

MaxPrimal, where are you based? If you are in the Reading area, the Kwik Fit in Wokingham could be a safe place to go for the suspension, as one of the MOT guys is familiar with Citroëns (he sold me my first car, a BX). I know he used to have a CX estate (series 2), and a BX estate, and he knew what he was doing to maintain them.

I'd say PTS in Wokingham is probably a better bet than Kwik-fit if you're in that area

[MaxPrimal]

I am near Portsmouth sadly so that is a no-go for me.

I had a quick test of the suspension when I was waiting for my wife. When I pushed down it went down okay without too much force, when I tried to push it a second time the car seemed to resist me which I assume this Hydractive 3+ suspension moving to it's firm mode to counter the perceived roll.

What I was going to ask was: What is passive rear steering?

If the suspension is okay - which it seems to be to me. It could be a quirk of the car compared to my old 54 plate Primera. I just get the sensation that the car will go from me if I try and ask to much of it on corners, where as my old Primera felt firmly glued to the floor no matter what speed or angle I put the car at.

Just a couple of other thoughts to run past you. When I got the car it had a new MOT on it with a couple of advisories. Could any of these be part of what I an feeling? :

Nearside front tie bar/rod has slight play in a ball joint
Nearside front Front constant velocity joint is slightly warn

I just noticed there was an advisory on the offside rear tyre as well. Never saw that. I will check the rear tyres tomorrow. Be pissed if I have to change them as well as I cannot really afford another £100.

Max

[MaxPrimal]

nice and soft. If the spheres are shot or the rear suspension arm bearings are shot the rear will wander wide on rough surfaces as it can't follow the road to grip properly.

just seen the image you added. Surely that shows the tyres toeing in not out as they are closer together at the front of the tyre than at the back or am I missing something/is that just an illustration but not an image showing the actual alignment?

Max

[myglaren]

One of the stand out things I have observed on both my C5s is that they will outperform most other cars on corners, bends and roundabouts.
Can't recall ever doing a u-turn in it.

[Mandrake]

nice and soft. If the spheres are shot or the rear suspension arm bearings are shot the rear will wander wide on rough surfaces as it can't follow the road to grip properly.

just seen the image you added. Surely that shows the tyres toeing in not out as they are closer together at the front of the tyre than at the back or am I missing something/is that just an illustration but not an image showing the actual alignment?

Max

The image shows toe in, but its just an illustration. If you read the text below it carefully you'll see that it defines what a positive and negative tracking value means (positive being wheels toeing in at the front) and then lists the tracking value as a negative figure in the table - its definitely toe out that is correct. Anyone else want to back me up on this one ?