Let me explain, water pump went out after 13 yrs of great service (got my monies worth). Some time ago I replaced my motor mounts cause they were just down to nothin. So I get the water pump replaced n notice my factory fan is all scuffed and has some cracks. I go ahead n change it. After all work is done, i go for a test drive n it feel waaaaay more smooth than before. Seems the fan was causing vibration, in turn making engine shake n such. I mention it to my mechanic n he agrees it will allow the car to focus on putting out power vs fighting not to vibrate. Checked all seals, make sure all pullies aligned. Probably gained back a few HP that was being robbed by the vibrations. Who would have thought a simple fan would cause such a headache. Word to the wise!