[Jekyll]

Had my E91 320d Edition M Sport for a month now and started to feel some slight understeer on dry corners that I know well - which was a bit surprising. On a long trip this got worse and varied from mild understeer type sensation in some corners to the point where on a very twisty section of road doing between 30 and 50 mph I felt I had almost no control and was only guiding the car through the corners.

Checked tyre pressures and all seems physically OK. As the problem had got worse and I had a long drive home I call BMW assist who came out to in 3 hours to a very remote part of Scotland. They couldn't find anything wrong but the mechanic could kind of feel what I was talking about. So they towed the car back to Glasgow where it is now. They sent out a hire car right away.

The dealers have phoned me and say they can't find anything wrong on a motorway test drive or on the diagnostics. I have explained in more detail what I was experiencing and they are off to look again.

Anyone have any ideas what might be up? Might this be related to the electric power steering?

[330cdsport]

That is very scary. My wife's E91 320d handles brilliantly in the corners, although it is the non-ED model.

[booforty]

Understeer is a word we don't see very often on this forum, I'm sure the various E91 owners will chip in but I've have not heard of them experiencing this...

[xenon]

If the tyre pressures are OK get the stealer to KDS it.

[jjbirch]

with big fat tyres on too, that thing should stick to road, i never had any thing like that before, but my car is not ed model

[Jekyll]

Originally Posted by xenon

If the tyre pressures are OK get the stealer to KDS it.

What's KDS?

[xenon]

http://www.diagnostics-oes.de/diagno...generation.pdf

[neilmc]

I have an ed model and no understeer at all or odd feeling steering.Have you used tyre cleaner recently or is there any sign of oil on the sidewall? although this should wear off quickly.Only other thing could be a steering fault.Let us know how you get on.

[dxb335d]

Originally Posted by booforty

Understeer is a word we don't see very often on this forum, I'm sure the various E91 owners will chip in but I've have not heard of them experiencing this...

Ive experianced alot of OVER steer LOL.

Very tail happy.

[Budgie]

Originally Posted by dxb335d

Ive experianced alot of OVER steer LOL.

Very tail happy.

Mmmm no comment ...The DXB vs WXB lol

The hills are alive with the sounds of Denzil...lol

[gIzzE]

You sure it was understeer? I mean a bit of understeer is not unheard of, but you would have to be going into a corner pretty damned hard to notice it.

If it was more a case that the car didn't seem to want to turn into the corner it could be a steering fault, there was a guy on here ages ago that said he could not turn coming off a freeway exit and totalled his car going into the concrete wall, he got ridiculed by everyone saying he was going too fast, but he was adamant that it was a fault with the cars steering.

I used to own an S4 Avant and if anyone wants to experience understeer take one of these out, with the heavy V8 over the front axle it borders on dangerous. In comparison I would say the regular BMWs verge more on neutral rather than oversteer or understeer, being RWD they can get the back out, but I would say the chassis is very neutral.

This is what makes me think there may be a problem with the steering or something else??

[E92Fan]

Originally Posted by Jekyll

Had my E91 320d Edition M Sport for a month now and started to feel some slight understeer on dry corners that I know well - which was a bit surprising. On a long trip this got worse and varied from mild understeer type sensation in some corners to the point where on a very twisty section of road doing between 30 and 50 mph I felt I had almost no control and was only guiding the car through the corners.

Checked tyre pressures and all seems physically OK. As the problem had got worse and I had a long drive home I call BMW assist who came out to in 3 hours to a very remote part of Scotland. They couldn't find anything wrong but the mechanic could kind of feel what I was talking about. So they towed the car back to Glasgow where it is now. They sent out a hire car right away.

The dealers have phoned me and say they can't find anything wrong on a motorway test drive or on the diagnostics. I have explained in more detail what I was experiencing and they are off to look again.

Anyone have any ideas what might be up? Might this be related to the electric power steering?

Sorry to hear of your troubles. Given the car is only a month old, it seems unlikely that there is a direct mechanical failure of something like the suspension struts or the lower wishbones (which would be one of the main causes of sudden understeer).

Have you gone over a very sharp bumps or into potholes? Or mounted a kerb? As has been alluded to already, perhaps the car needs a KDS, or posh 4-wheel alignment using a Beissbarth machine. If the car is only a month old, the KDS will be done under warranty (if the dealer argues, argue back saying that BMW UK will verify that the KDS is under warranty within the first two or three months or first 4000 miles)

Also tell your dealer to forget about looking at the GT1 computer and do some proper mechanical checks - that blasted machine won't detect whether an anti-roll bar bush has failed, or whether the strut assembly is damaged etc...

As a last resort, if you are still not confident in the mechanical state of your car, contact BMW UK Customer Service and raise an official case with them.

Good luck!

[Porscha!]

Not sure if I've seen that video before but how fun?!

I want to join in haha

[dxb335d]

Originally Posted by Budgie

Mmmm no comment ...The DXB vs WXB lol

The hills are alive with the sounds of Denzil...lol

PMSL, we could start a ''Denzil Act'' LOL...

[Porscha!]

Originally Posted by dxb335d

PMSL, we could start a ''Denzil Act'' LOL...

ooooooo If I do buy a Landy for the winter can I join too?! Pleeeeeeeease!

[dxb335d]

PMSL, course ya can, it will be good fun!

[Jekyll]

thanks guys. I will let you know how I get on tomorrow.

[dxb335d]

Good luck bud.

[booforty]

Originally Posted by Budgie

The hills are alive with the sounds of Denzil...lol

This song needs to be recorded!

[NFS]

Originally Posted by gIzzE

You sure it was understeer? I mean a bit of understeer is not unheard of, but you would have to be going into a corner pretty damned hard to notice it.

Gizze, I think you are right. If the car was really understeering, then it would simply not be turning in, just plowing straight ahead.

It sounds like this is a steering problem to me.

[Jekyll]

They still can't find anything wrong. They maintain they've been out in it and it "drives like any other touring" so the fault must be intermittent.

They have reported the fault to BMW Technical who have not yet come back with a reply some 2 days later. The mechanic I spoke said that was strange as it usually takes 5/6 hours, so he suspected they were looking into a similar case before they reply.

I told him was has been written here about the alignment check and he said BM would pay for it within the first 4000 miles as long as something was wrong. If I request it and there's nothing wrong will cost me £200

Will keep you posted.