[///ASN]

May I ask what could be wrong if the steering wheel is going left and right violently by itself when the car is driving at high speed?

At 100km/h, even holding the steering wheel tight, still can feel the steering wheel/the car is turning to left and right by itself.

*Alignment has been done recently, no error code, haven't hit any pole hole
**car is stock

[MJ80.]

Rotors could be warped.

[EB89]

Wheels bolts tight?

[Rajvosa]

front control arm bushes?
if you go over a speed bump, does the steering move left or right hard?

[Ken Oath]

Previously it was mentioned that scalloping was observed on the tyres.
Perhaps you could start with a wheel balance, check tyre pressure, rotate tyres, remove any spacers, check wheel bearings and check for any play in suspension and steering components.

Like most problems it's usually the 'nut' holding the steering wheel 8-)

[PerthBMW]

Stop moving your hands whilst driving???

[rooks335]

All good advice above, could also be the road being uneven? You did mention high speed so assuming its highway nice and flat

[///ASN]

Originally Posted by Ken Oath

Previously it was mentioned that scalloping was observed on the tyres.
Perhaps you could start with a wheel balance, check tyre pressure, rotate tyres, remove any spacers, check wheel bearings and check for any play in suspension and steering components.

Like most problems it's usually the 'nut' holding the steering wheel 8-)

It's not my car.

[///ASN]

Originally Posted by Rajvosa

front control arm bushes?
if you go over a speed bump, does the steering move left or right hard?

Don't feel like the steering move left or right hard when going over speed bump.
When driving slow, the car is steady, it just starts getting vibrating above 70km/h and getting really violent at 100km/h

[///ASN]

Originally Posted by EB89

Wheels bolts tight?

tight and firm like a 18 years old girl

[juld0zer]

Humps in the sidewalls? (internal tear)

[e36mmm]

Originally Posted by PerthBMW

Stop moving your hands whilst driving???

[TIRA]

Spacers? :P

[NBTBRV8]

I am going through this at the moment. I presume you are talking about tram tracking, mine does it badly and I am replacing both of these arms this week to try and reduce it.

http://www.realoem.com/bmw/enUS/show...diagId=31_1219

I've had a 4 wheel alignment done and the tyre pressures are fine, the tyres are the BMW Bridgestone RFT types, but the car does wander over the road and it particularly noticable at highway speeds, you constantly have to steer it.

[satz]

if it's the tramtracking, or tramlining, I was getting that really badly on my E90 with Bridgestone runflats. But it happened mainly at lower speed, coming to a stop.

Had the car aligned twice, incl by BMW. Didn't improve things. One suspension place told me it was characteristic of run flats.

I changed the front tyres to non RFT, and that reduced the tramlining dramatically!

[satz]

Wheel balance weights fallen off?

[KiwiRD]

Likely tramlining - as others have said. Basically the tyres start to 'follow' imperfections, grooves and channels that exist in the road surface, which the naked eye may not pick up when doing 100kph down the freeway. The effect, as you can imagine' is the same as tram wheels following tram tracks. It almost feels like the wheels are steering the car. Some tyres suffer quite badly from this - especially runflats. Alignment will not really prevent this happening - it's the combination of road surface and tyres.

[NBTBRV8]

I just picked my car up from the dealer, who changed items 10 and 14:

http://www.realoem.com/bmw/enUS/show...diagId=31_0715

In the short drive home it has transformed the car, absolutely no sign of tram lining and you would not credit it was the same car.

All up not cheap

Item 10 $113.75 + GST each (2 needed)
Item 14 $304.14 + GST each (2 needed)
Labour to fit $270.00 + GST
Wheel alignment $150.00 + GST

I will know more in the next few days and when I go out on the highway next, but wow, what a difference.

[Armadyllo]

Could be Bent Rims, Mine does the same over 100 hit 120 and you really notice it. Those damn runflats have tendency of destroying our rims.

Get them spun up (balanced)

[///ASN]

Thanks everyone, I will pass these info to my friend.

I think he has to start checking with the easier thing first - wheel balancing
this shouldn't cost much to check at a tyres shop.

The tyres surface seem flat and don't think there is any uneven wear.