Recently after I got my alternator and battery replaced, I noticed that after a night or two whenever I tried to start my car (after engine turned on), I heard a rattling sound if i started shifting gear from park to either reverse or drive. The noise went away if I proceeded to hit the gas. I hear no noise after I started driving.
What could be the cause of this? Would it be something that the mechanic screwed up on?
My car is Toyota Camry 2006