I have a 97' z24 with the 2.4. When I first start the car it sounds normal but after it heats up the engine sounds like it struggling. If I move the steering wheel a little to the left or right and hold it there, the sound goes away. At first I thought it was the pump because it's driven by the camshaft and it's putting stress on it. So I replaced the pump and bled the system. It sounded normal at start up but after a few minutes of driving the struggling sound came back. Anyone have any ideas? My next step is to flush out the old fluid because I think thats whats causing the pump to work harder after the fluid gets warmed up. Or I have a rack problem.