Hello. The power steering pump normally makes all sorts of weird noises when it's going bad. Not 100% of the time, but it is really, really strange when they just die in silence. They usually go out screaming.:gringreen The cylinder, on the other hand, usually does not make any noises, and it would make perfect sense for the higher rpms to help a failing cylinder for a little while because of the increased pressure generated by the pump. Try taking the belt off of the power steering pump. If that doesn't change anything and it still steers just like it did, then it's probably the cylinder. Hope that helps.