SUBARU IMPREZA 07 My power steering makes a whirring / whning noise which is now an almost permanant noise. I have been told at my last service by Subaru I will need to replace the power steering valve which they say is not opening - therefore the noise is occuring. However they only said to replace it if it bugs me, I can't do anything to damage it by driving it continually. I just want to confirm that that is right, if it happens almost all the time, can I not do damage by driving? They want 0 to fix it parts and labour, and I don't have that money for a couple of weeks. Alternatively, would some of the power steering additive fluids that auto shops sell help out?