Strange cornering problem

[Peter Palmer]

2 of us drive our van - citroen dispatch 2015 and my mate reckons the van has a mind of its own, he describes it as when going round a left hand corner at a sensible speed the van suddenly snaps harder to the left and he has to correct it by steering right. He says this only happens occasionally. the van doesn't slide, he says its like someone suddenly yanking the steering harder to the left. Personally when I have driven it I havent really noticed anything but he does drive it down more country roads than me.

I recently changed both front lower arms as the ball joints were a bit past it but he says this hasn't solved anything. What could it be? The van isn't overloaded and nothing is shifting about in the back, the tyres are also pretty new and I didn't see anything that had obvious play in it when I changed the arms. It has done 210k miles though.

[mickthemaverick]

The only time I have come across that type of problem I found the front upper ball joint on the opposite side of the car had excess play allowing the outside wheel to alter camber resulting in a sudden tightening of the steering angle and an apparent dive to the left. That was on a C15 van so may be worth a check!!

[Peter Palmer]

The only time I have come across that type of problem I found the front upper ball joint on the opposite side of the car had excess play allowing the outside wheel to alter camber resulting in a sudden tightening of the steering angle and an apparent dive to the left. That was on a C15 van so may be worth a check!!

Could be but I can't remember if these have top ball joints, there is a lower arm with the bottom ball joint, then the strut which has the anti roll bar attached and the steering arm, don't recall seeing anything else on it.

This is a picture of the complete strut and it only seems to have places to connect the sway bar, brake calliper, bottom ball joint and track rod end, doesn't seem much to go wrong with it really.

[mickthemaverick]

That being the case I'd suggest you check the offside strut top mount to ensure all is well. Purely speaking logically something must move to alter the steering angle once cornering forces are applied and as you say there aren't that many possibilities!!

[Peter Palmer]

We still have this problem with our van, so far I've replaced both lower arms as the ball joints were a bit worn and its had 4 new tyres so that rules tham out, it also rules out buckled wheels etc as they have all been on the balancing machine. I've thoroughly checked every ball joint, bold, bearing etc on all 3 wheels and nothing has any play in it whatsoever yet the van still snatches to the left round fast left hand bends.

What I've noticed though is its only when the steering wheel reaches about 90 deg of left turn, hold it at 85 deg and it corners normally, turn it slightly more and it snatches to the left, let it go back ro 85 deg and it snatches to the right and back on track. It must be something to do with the power steering rack.

I've found a few second hand racks on ebay but most seem to be for the 2.0 HDI one, ours is a 1.6HDI. Can anyone check if the 2litre one will fit a 1.6, details are as follows.

2015 dispatch enterprise van 1.6 HDI, VIN number VF7**************[VIN obfuscated, can be read by forum staff]

Thanks for any help. How do I donate to this forum by the way, I've had enough help off it over the years.

[Rp0thejester]

Just look at the top and there's a donation section, I'm intrigued about this problem....

[Rp0thejester]

I'm thinking if the rack was bent it would also pull to the right. Have you checked the suspension strut for straightness? It's the only thing I can think of that would cause that if you've checked everything else. A slight bend wouldn't be noticeable in a straight line but taking corners would exaggerate the issue. Is tyre wear an issue on that side?

[Michel]

You have had the wheel alignment checked and set properly by a competent person, haven't you? This sounds like the issue my old ZX had - twitchy AF one direction, lazy the other. It had had the tracking done by an incompetent place and was way out. Drove straight though!

[Doo]

I have come across a similar issue and it turned out to be the tyres!

Two different makes on the front. One provided more grip than the other....

Also, speaking of steering, I had a Smart For 4 with a jakey steering rack. The electric motor was gubbed. Replaced it and all was good once more. The steering would go a bit funny. Nice & light until you steered to a certain point and then it would get heavy. Driving it was always a hoot.... NOT But soon as the motor was changed, it was great.

[thorter]

Does the rear subframe have passive steering like the ZX did? If so, degraded rubber mounts can cause this sort of thing.

[Peter Palmer]

OK, I think I've had a breakthrough, the van has also had a warning light on for a bit and that is the ABS/TCR fault light, its never on when you first set off and only comes on when you have been driving for a bit, I scanned the codes today after a tip by soemone and its saying there is a fault with the steering angle sensor.

I think the TC is getting confused when the steering wheel is in a certain position and grabbing the brakes. The TC light was certainly flashing on and off today when the fault happened. Can something electronic really cause a fault that feels like it has to be mechanical though, you would think the wheel was falling off when it happens.

[Peter Palmer]

Still having problems with this strange fault. It seems to be worse now as well, right hand bends are no problem at all for it, at any speed howver its very twitchy round left hand bends, the tighter they are the worse it gets, even at low speeds now.

On certain bends the traction control is kicking in and flashing the orange light in the cluster as well as removing the power although the van definitely isn't skidding anywhere. If anything it feels like excessive torque steer and it has even developed a bit of that off the line now if you accelerate hard. I reset the steering angle sensor ages ago and currently have no error messages at all.

[Rp0thejester]

I'd be looking at track rod end or camber settings/suspension. It seems mechanical that's giving a reading to the ECU which makes the other side work overtime

[xantia_v6]

Did you do anything about the steering angle sensor?
How repeatable is the fault? Is it worth disabling the traction control to see if that stops it?

[Peter Palmer]

Did you do anything about the steering angle sensor?
How repeatable is the fault? Is it worth disabling the traction control to see if that stops it?

I sorted the sttering angle fault out by re-calibrating it in diagbox, forget what I did now but something like turning lock to lock a couple of times or similar and since I did that I've not had any more error messages regarding that.

I'm sure it must be mechanically related, I'll delve into looking at the rear subframe/axel bushes next weekend. It is a daft fault to have though because if I knew what it was I could fix it no problem.