A few months ago I had a brand new water pump installed in my '05 Chevy Cobalt. Ever since then, the car makes a whining sound when accelerating. I took my brother for a ride in it to see if he heard the noise, which he didn't. My uncle (who's friend is the mechanic that replaced the water pump, he's a professional and has his own shop) says it's nothing to worry about. I disagree. It never did it before and I am concerned that further damage could be caused if this isn't taken care of. Any ideas on what this could be??