kernel_task is using 600% CPU usage consistently and the costly Apple Store repair did nothing to fix it. Advice?
So about a week ago I noticed my 1 year old Macbook pro was running really slowly. Activity moniter shows that kernel_task is using between 500-700% CPU (I have 8 cores), even with no applications running. I took my computer to the Apple store and after two days of running tests they told me that I needed to replace my hard drive. I speant $180 repairing the hard drive, but when I got home and resetup my computer, the problem was not only gone, but in fact it seemed to be worse.
I really need my computer, but I don't have money to just throw away on guesses on what would fix my computer. Does anyone know what could be causing this? Maybe Apple will foot the bill of my repair since it didn't do anything?
MacBook Pro, OS X Mountain Lion (10.8.2)