Technical Steering feeling weird

[Bellisimo]

Hello all. My wife's 2009 500c which has only done 38k has recently developed an odd feeling to the steering and some wisdom on how to proceed would be welcomed.
With engine running and car stationary the wheel feels normal when turned back and forth and has the usual tendency to want to return to the central position, however as soon as the car is moving you can 'feel' the power assistance almost 'over assisting' when any effort is made turning the wheel with a definite 'stop in assistance' as soon as driver input is relaxed yet if you removed your hands from the wheel there is no further movement on the wheel trying to return to a central position at all. This is regardless.of how much the wheel has been turned from the straight ahead position.
I have had it checked by my local garage who say they think it is the power steering motor/column at fault but the car is displaying no error code or warning light so are somewhat confused. City mode does not really affect it.
Anyone got any ideas?
Thank you.

 

[John202020]

Hi, check the basics first, both front tyres ok, same type, correctly inflated not unevenly worn then look at the suspension to rule that out, if it's never had any work on it, it's probably well tired, generally 8 years regarded as the point various parts (or all ) need replacing ?
If it's never had the engine earth strap replaced, it will need it replacing

 

[Bellisimo]

Hi, check the basics first, both front tyres ok, same type, correctly inflated not unevenly worn then look at the suspension to rule that out, if it's never had any work on it, it's probably well tired, generally 8 years regarded as the point various parts (or all ) need replacing ?
If it's never had the engine earth strap replaced, it will need it replacing

Hi John202020

Thanks for your speedy reply.
The garage swapped the front and rear wheels and checked the suspension too which was ok.
Interesting about the earth strap but how would that affect the powe.er steering?
The fact that it seems ok when stationary suggests input from a movement sensor may be what is triggering the power steering to act weird but then I would expect an error code.

 

[John202020]

Interesting about the earth strap but how would that affect the power steering?
The fact that it seems ok when stationary suggests input from a movement sensor may be what is triggering the power steering to act weird but then I would expect an error code.

It could very well be the torque sensor
Whilst I don't think its the reason( for your problem ) its well known that this £5 part fails causing all sorts of odd electrical issues, typically starting and steering and charging but not all the time, it goes from the chassis to the gearbox under the battery tray, its always worth replacing if never changed.

 

[Bellisimo]

It could very well be the torque sensor
Whilst I don't think its the reason( for your problem ) its well known that this £5 part fails causing all sorts of odd electrical issues, typically starting and steering and charging but not all the time, it goes from the chassis to the gearbox under the battery tray, its always worth replacing if never changed.

Ok, definitely worth replacing along with the earth strap before proceeding further I think.
Many thanks for this.

 

[koalar]

I am having a hard time understanding what the symptoms are

How long have you had the car. Has it always done this
Did it come on gradually or suddenly

If you turn the steering wheel while the engine is on but the car not moving. The sidewalls bend and when you let go of the steering wheel it bounces back. This is normal.

If it’s the same turning left and turning right it’s almost certainly not the torque sensor and unlikely to be EPS

If its worse the fast you go it likely to be something binding. Such as a faulty rack which are normally fine at car park speed but as soon as the assistance is reduced feels “sticky” can’t think of a better description


General wandering, vagueness is going to be

Tyres
Tyre pressures both front and rear
Suspension or steering parts loose
Suspension or steering parts bent
Suspension or steering parts worn

 

[Yolanda]

Try running a jump lead fron the Neg terminal on the battery to the engine block. If it cures the problem it will be the earth lead that John202020 mentioned.

 

[Bellisimo]

I am having a hard time understanding what the symptoms are

How long have you had the car. Has it always done this
Did it come on gradually or suddenly

If you turn the steering wheel while the engine is on but the car not moving. The sidewalls bend and when you let go of the steering wheel it bounces back. This is normal.

If it’s the same turning left and turning right it’s almost certainly not the torque sensor and unlikely to be EPS

If its worse the fast you go it likely to be something binding. Such as a faulty rack which are normally fine at car park speed but as soon as the assistance is reduced feels “sticky” can’t think of a better description


General wandering, vagueness is going to be

Tyres
Tyre pressures both front and rear
Suspension or steering parts loose
Suspension or steering parts bent
Suspension or steering parts worn

Hi Koalar

We have had the car from new so it is 14 years old but only done 38k, and we have never had any fault with the steering before. Increased speed does not make it better or worse.
I noticed it after it was returned from being serviced and had two new front tyres fitted. The strange feeling was there straight away so I obviously queried the garage who said nothing they were aware of could have caused it, swapped the front and back tyres to eliminate that and checked the steering and suspension. So I am feeling it may just be coincidence in a car that old. The garage technicians agreed the steering felt 'awful.
There is no vagueness but it would leave the road if you took your hands off the wheel.
It is difficult to describe other than it is as though someone else has hold of the steering wheel and as soon as any effort to move the wheel is sensed it 'assists' too much (almost making you over steer) until it senses you no longer want further movement whereupon it then 'holds' the wheel at that position. Very 'on and off' not like seemingly unobtrusive power assistance is normally. Because it has this 'hold' between movements is why I say the car would leave the road if you relaxed grip on the wheel. Usually the more you turn the wheel the more the steering naturally wants to recentre but this is not the case now.
Thanks

 

[koalar]

Hi Koalar

We have had the car from new so it is 14 years old but only done 38k, and we have never had any fault with the steering before. Increased speed does not make it better or worse.
I noticed it after it was returned from being serviced and had two new front tyres fitted. The strange feeling was there straight away so I obviously queried the garage who said nothing they were aware of could have caused it, swapped the front and back tyres to eliminate that and checked the steering and suspension. So I am feeling it may just be coincidence in a car that old. The garage technicians agreed the steering felt 'awful.
There is no vagueness but it would leave the road if you took your hands off the wheel.
It is difficult to describe other than it is as though someone else has hold of the steering wheel and as soon as any effort to move the wheel is sensed it 'assists' too much (almost making you over steer) until it senses you no longer want further movement whereupon it then 'holds' the wheel at that position. Very 'on and off' not like seemingly unobtrusive power assistance is normally. Because it has this 'hold' between movements is why I say the car would leave the road if you relaxed grip on the wheel. Usually the more you turn the wheel the more the steering naturally wants to recentre but this is not the case now.
Thanks

Great, so you know how the car should feel and it was a sudden change

Straight after a service I doubt it’s coincidence

When the tyres were changed did they do the tracking at the same time ?

You say if you take your hands of the steering wheel you’d crash

Is it pulling to one side,

 

[Bellisimo]

Great, so you know how the car should feel and it was a sudden change

Straight after a service I doubt it’s coincidence

When the tyres were changed did they do the tracking at the same time ?

You say if you take your hands of the steering wheel you’d crash

Is it pulling to one side,

I am not sure without asking them which I will do along with changing the torque sensor and earth strap.

Great, so you know how the car should feel and it was a sudden change

Straight after a service I doubt it’s coincidence

When the tyres were changed did they do the tracking at the same time ?

You say if you take your hands of the steering wheel you’d crash

Is it pulling to one

 

[koalar]

I am not sure without asking them which I will do along with changing the torque sensor and earth strap.

Torque sensor and earth straps should be fine

Went in for a service and it was fine

Came out of a service and it was wrong

The car been on a lift wheels dangling down at not there normal angle

Top mount, lower control arm

Air impact gun used

Ball joints, wheel bearing

If the tracking was done with the tyres

Tracking wrong
Inner or outer track rods ends


To drive in a straight line do you have to apply some force to the steering wheel constantly

 

[Bellisimo]

Torque sensor and earth straps should be fine

Went in for a service and it was fine

Came out of a service and it was wrong

The car been on a lift wheels dangling down at not there normal angle

Top mount, lower control arm

Air impact gun used

Ball joints, wheel bearing

If the tracking was done with the tyres

Tracking wrong
Inner or outer track rods ends


To drive in a straight line do you have to apply some force to the steering wheel constantly

It will drive in a straight line if you have the steering wheel straight ahead when you relax controlling the steering wheel. Basically whatever position you have the wheel in when you relax any pressure on the wheel is where it will continue to go to (it seems to hold that wheel position), ie it will not to 'any' degree attempt to straighten up.

 

[koalar]

What are the tyre pressures front ?

Has the garage set them higher than you normally run them

 

[John202020]

I noticed it after it was returned and had two new front tyres fitted.

Were they the same make as before?
Note the new tyres should have been fitted to the rear, the old rears to the front

 

[Bellisimo]

Were they the same make as before?
Note the new tyres should have been fitted to the rear, the old rears to the front

No they are a different make and they are now on the rear wheels.

 

[Yolanda]

Top mounts on the way out maybe.

 

[Bellisimo]

Worth a try
Thanks

 

[Bellisimo]

If we can get the steering sorted we will try to get up to join in.

 

[Bellisimo]

Thanks for everyone's input on this, the car is booked into our garage for going over your suggestions. I'll let you know what was found.

 

[Barney Rubble]

Apologies for hijacking the thread, but my daughters Fiat 500 2015 lounges 1.2 has exactly the same issue. I have no fault codes, earth lead and suspension components are fine. Track rods disconnected and the shock assemblies move freely. Wheels have been swapped front to rear and it made no difference. I’m thinking the fault lies with the torque sensor. But I’m not convinced enough to bite the bullet.