Today I found my Corsa C 2002 suddenly needs more steering to make angles. A left or right turn would normally take a about 90 deg angle on my steer. But now it needs more than 180 to do this manouvre. The steering itself doesn’t feel heavier to do but just needs more turning. The EPS on the dash doesn’t light while ignited. Could this be some sort some of angle memory?
I'd suggest the following tests:
Firstly, with the car stationary, try to turn the steering wheel gently while an assistant watches the road wheels - if you can turn the wheel some distance before the roadwheels start to move, you've got something loose in the steering mechanism. If this is the case you should also feel that the first part of the movement of the steering wheels feels "looser" than usual.
Then jack up the front of the car, and support on axle stands. Get your assistant to turn the steering wheel from side to side while you look underneath to see what's happening. Pay particular attention to the steering rack (these can sometimes move from side to side if the mounts get loose), the various suspension linkages and the track rods (the bars that link the wheels to the steering rack) - hopefully you'll be able to see what's moving that shouldn't be. Listen out for any odd noises too, like a "clunk" as the slack is taken up (which you may not have heard in normal driving over the noise of the engine).
Also, as you've mentioned electric power steering - while the front of the car is jacked up, stand clear and switch the ignition to the "on" position (but don't start the engine). If the steering suddenly moves by itself, you might find the torque sensor on the steering column has either failed or become misaligned - I had that once on a previous car that kept pulling to one side - I did this test and the EPAS immediately turned the wheels fully to the right. All it needed was to adjust the sensor and the problem was cured.
Thanks for taking your time answering! So today i did some test like you mentioned, but neither of the possible issues you described occured. I made a call to a local Opel dealer to check it out for free, so I went to them and made a drive with a mechanic. He didn’t found the steering a problem and he verified it’s not a mechanical problem, though told me the right steering was a bit harder due to the fact roundabouts always force you to steer right when leaving. This causes wear on the motor at that side, wich is also the answer for my overall power steering problem, the motor is just wearing out a bit.
For now I’ll take it for granted, but if it decreases I might get a new one on a scrapyard ;-)