I have been driving this a bit much this year but my daily driver was in the shop. So here is what happened one day i heard this like noise almost thought it was my valve train and then i checked my lash all is good there. so I was talkin to a buddy of mine and he said it sounds more like a whining noise. try to change the fuild and see what happens. OH man bad idea now i really have a whining noise in all gears and real noticeable at a higher rpm. Any suggestion like bad front pump, anything.