Steering Wheel randomly feeling stiff

[Alecossy]

Hello people!
Same car ( 2002 1.6 80 KW Black 206 cc - just got it to 120.000 KM), new set of problems.

In the last few months, the steering wheel started to randomly "stiffen up" while driving. It would, at first, only happen in the city center or while making sharp turns (I live in a city which is based on an old Roman encampment, with vertical and horizontal streets forming sort of a net) but recently I started noticing that even simply taking a roundabout or a smoother bend would result in the same symptoms. No lights come on, the wheel is still responsive (it doesn't feel loose or anything) but slightly harder to turn.

It's not that big of a problem for now but I feel like it progressively gets harder to control the car and it really impacts on the overall driving pleasure. I'm wondering if any of you guys had a similar problem.

[GrandadMonkey]

Have you checked your power steering fluid? Has the level dropped so much that it needs topping up?

[Capncol]

Could also be ball joint or CV joint. Are there any noises when turning, groans or clicking?

[Alecossy]

Fluid seemed good, my mechanic took a look at it last time I took the car in and it was fine, I checked it again recently and there doesn't seem to be any kind of leak.
There's no noise when turning, none that I can hear from the inside or from the outside... A weird thing that I noticed is that if the car is left parked for a few days, the steering wheel will return to its original smoothness, and it will only gradually stiffen up again while driving...

[Stewface]

First things first, check tyre pressures. Could be a loose PAS belt or as Capncol said it could be a Ball joint, on the steering Column or a lower suspension ball joint, beginning to seize up. Worse case scenario would be the PAS rack has an internal fault, so would need to be replaced or refurbished.
That's the order I would start looking in, eliminate the basics first.

[Alecossy]

Pressure's fine.. but I will need to wait for the rest as I just replaced the MAP sensor I was speaking of in one of my other posts (student life means that basically killed my savings).

[Slo]

Do you have variable power steering? If you do it is regulated by the speed sensor.

[gazza82]

Do you have variable power steering? If you do it is regulated by the speed sensor.

Not sure it's available on the CCs.