Xantia Activa Squirrelly Handling Under Hard Acceleration

[Zelandeth]

Not sure if this is a specifically Activa related issue or relating to the conventional Xantia bits.

The issue here is that currently under hard acceleration the car feels fidgety - tending to pull somewhat to the right. This is only under power, braking still brings the car up dead straight whether it's gentle or standing on the anchors at 70mph.

The overall feel is very much like torque steer.

The front tyres have been well past their best for a while (full set will be changed shortly), and I'd assumed this was likely a contributory factor - until I swapped them around today and putting the rear tyres on the front had precisely zero impact on anything.

There has been a bit of a clonk from the front somewhere pretty much since I got the car, I specifically asked the MOT tester to give everything a good poke last year at the test and did find one stuffed lower ball joint (nearside), but replacement of that had no effect on the knock. Sadly as the car is used day to day it's hard to find time to track down stuff that's on the "slightly annoying but not affecting function" list. However I'd not be at all surprised if the clonk and this latest symptom are connected.

I've had a poke around and aside from a small split in the nearside CV boot I've not found anything obviously amiss. Rocking the steering doesn't show any play in track rod ends (that was my favourite theory) or any detectable play in stuff I can reasonably test on the driveway. No adverse tyre wear or feathering to indicate alignment issues either.

Hoping someone will be able to say "yes I had that and it's..." so I can just get the necessary parts ordered and pass it on to my usual garage to sort.

I have a rule that I don't do steering/suspension stuff these days. I've done that for enough years and have expended enough blood sweat and tears to know it's worth paying someone with the right tools and a four post lift to do that sort of work! I generally like to drop the car off though knowing what the fault is and to have a good quality part sitting on the passenger seat ready for them to fit...

[Stickyfinger]

Lower arm P-Bushes, plus maybe the front ones..............

[Zelandeth]

That's the sort of response I like! Thank you.

Got a picture handy so I can go spelunking in the spares stash to see if I have those in stock? 99% certain the answer is yes from memory from talking to Jim, just not parts I recognise by sight yet. Once I find out I'll get it booked into the garage to be sorted.

[Andy F]

Had the same on my Xantias in the past and it was lower P bushes, I replaced all bushes and it was like a different car. Agree it feels very much like torque steer!

[Mandrake]

I have exactly the same kind of mystery clonk in my Xantia V6 somewhere in the front right suspension and have had since I bought the car 5 years ago. It has got steadily worse to the point where it really ought to be fixed now. In particular I notice if I accelerate quickly away towards the right at a T junction it clatters something awful and you can feel it fighting the steering wheel. Not so bad pulling away straight.

I've had a look for this a few times now and so has the MOT man who has commented on it but not failed it as he can't pin down exactly what it is. Track rod end, drop link, lower ball joint have all been done since I've had the car - no change.

I'm now pretty convinced through a process of elimination it must be one of the lower arm bushes (despite the fact that they look OK) so I'm inclined to just get an arm with new bushes already fitted as I don't have the tools or temperament to go through the hassle of trying to swap new bushes onto the old arm...

So I'm watching with interest to see if new bushes or arm sort your problem.

[yannbeam]

I had an annoying knock on the v6 when I got it. Turned out to be the front bush in the bottom arm. It moved very slightly forwrd and backward in the arm. The bushes were changed for the previous mot before I bought it, and I assume they had cleaned the hole to press the new bush in and had made the hole slightly oversize. Or the new bush was just s**t.

Very difficult to find as the movement was only very small. But it sounded terrible !

[Michel]

The clonk is the front lower arm bushes. I recall Jim having this issue on the left hand side of what is now Zel's Activa. Mystery clonk, couldn't work out what it was. Found out by accident when levering something else that it was the front lower arm bush.

[myglaren]

Isn't there a trick to fitting these - precision of orientation and then final torquing with the weight of the cat on the wheels.

[Zelandeth]

Well the garage that will be doing this most likely know the car and I trust them to do the job right. The clonk (or possibly conks) have definitely got worse over the last year. Not helped by the fact there are several possibilities...and the fact that the exhaust has recently taken up knocking horribly as well. Oh, and the offside strut creaks too which probably masquerades as a clonk from time to time.

Hoping given that there's enough play in things now that it's actually affecting the geometry under load that it should be easy enough to spot what's responsible - that's definitely a new development in the last month or so. Prior to that she pulled perfectly straight - only wandering being what you'd expect from anything trying to put down what I reckon is around 170bhp through the front wheels with no traction control.

This has become most noticeable right around the time that the front tyres "dropped off the cliff" they seem to at the end of life, which is why I initially looked at them as main suspects. Obviously they still need changing!

I'll go have a dig around in the box of bits tomorrow and see what I can find. Seem to recall having quite a few bits of suspension in there. P-bushes I definitely remember Jim mentioning by name when we were stuffing things in boxes so they should be in there...

Can anyone with access to such things provide some diagrams of how everything fits together? The engineer in me wants to visualise what's going on...

I think these cars make any knocks sound particularly horrendous at least in part because they're just so quiet otherwise. Always surprises me whenever we go anywhere in any of Chris' company cars (usually £40K plus Audi's these days...better him than me!) how much general road noise and engine drone there is compared to in the Xantia. Wind noise too in some of them.

[RichardW]

Generic picture

Item 9 is the front bush. IIRC there is something odd about the Activa arms in that they have a threaded bush on them, and something is screwed in, so you will have to fit new bushes. I suspect the job is best left to a specialist as well, as it probably involves re-setting the Activa control rods.

[RichardW]

Yep.... here's the drawing about removing the roll control linkage - you can see that it is bolted to the bottom of the arm by the front bush (at 7) - I presume the bolts (8) are bolted to the end of the subframe. This will need to be removed I imagine to get the arm out - it's well known that people not in the know bend up the roll bar to get the arm back in on 'normal' cars, which can bend / break the height corrector connection - this must be amplified 10 fold when the Activa bit is taken into account. I also think that putting the front bush in a bit tricky as the arm is not square. If it was mine, in your position, I would be thinking about a trundle down the M1 to BL Autos!!

[Zelandeth]

If it was mine, in your position, I would be thinking about a trundle down the M1 to BL Autos!!

Sounds like a plan to me then... recommendations are always useful, but especially marque specialists.

In fairness the car has barely needed anything sorted beyond routine maintenance over the last couple of years and is generally driven in a "spirited" manner (probably has something to do with my 23mpg average!) so it's really about time she got some attention...

Going to be an expensive month or two... there's this, a split CV boot (found when swapping tyres around), set of tyres and an exhaust going to be needed! Well worth it though...

[RichardW]

No personal experience, but they did the V6 conversion on David Hallworths Xantia - and he likes them so much he drove from Glasgow to get a load of jobs done on his C5!

[Stickyfinger]

They also run one themselves, Robert will work wonders on an Activa.

[van ordinaire]

Not their 1st endorsement I've read in these very pages (the name stuck, because it's so unfortunate ) - must mean something.