My wife has a 2004 Astra 2.2L Convertible. Great car but recently (about 6 months now) the steering feels sticky. It only does it first thing in the morning (ie first time its used and usually its cold). Once the rack has been turned a few times its fine. Its almost if the PAS has stopped working for a split second and you really feel the weight of the car/engine.
I've put my opel-scanner on there and read the current draw, about 60A max when you turn the rack back and forth quick - so the alternator seems fine.
Some people have said its the electronic pump. I believe my car has TRW Generation 2 fitted.
It had new front tyres a few weeks back and while it was up on the ramps the guys let me had a good look around at the ball joints etc. All seem fine to me, no give apart from one of the tie-rod bars I can spin the shaft by hand. But then again they are supposed to spin aren't they otherwise you can't adjust the tracking?
Anyway, I just wondered what other users have experienced.