Steering Issue

[MärkJ]

Hi guys,

Yesterday my IS200 developed a stiff steering feel. Basically, I went out in the car and all was fine. I parked up for about 5 minutes and when I set off again I noticed that the steering felt quite stiff compared to usual. It seemed to develop all of a sudden. It seems to handle okay on corners but the steering doesn't seem to want to centre like it usually does. Usually it will do without any problems but it seems almost as though something is resisting it and needs a bit of persuasion.

The only way I can describe it is it feels a bit like driving on under inflated front tyres. The first thing I did was check all of the tyre pressures but they were all fine (even the rears) at a nice 35psi each.

I then thought maybe a sticking brake so I jacked up each front wheel but both were spinning freely with no rubbing or bearing rumble. Rocked the wheels up/down and side to side but no loose play that I could feel.

Checked the power steering fluid and there's plenty in there. Also checked the power steering pulley belt and no problems there that I could see. The pump is operating (at least to a certain extent) as it's definitely not as stiff as when the engine isn't running and I can hear the release valve thingy working when the wheels are at full lock. Engine revs pick up fine from idle when turning the wheels with the car stationary. Fluid bubbles a bit with the cap off the reservoir when operating the steering.

I sprayed the steering column UJ with a lot of WD40 in case that was seized but hasn't made a difference.

Anybody have any other ideas, please? :( Is it likely that the pump is on it's way out or have I overlooked something really obvious?

Thanks in advance!

[chrisgixer]

Pas pumps in my experience tend to fail at low rpm first. Does rpm affect it, ie is the steering heavier while manoeuvring/parking. Guessing not from your description.

Not sure if IS has speed sensitive pas. If so It might be worth a diagnostic session to check electronic faults there.

Other than that...I guess a failed steering component...top shock mount? Any knocks?

[MärkJ]

It does feel heavier at slow speeds but then it was always heavier at slow speeds anyway (just not that heavy). No knocks that I've heard but I'll have a look at the shocks anyway.

After using for about a week it seems to have times when it feels heavier than others. It might start off stiff, then get lighter for a short while (although not as light as normal) and then go back to heavy again.

Thanks for the suggestions, though. I'll get them checked out. :)