Well, its not "just" hitting bumps, mine car does that all the time and it does not happen, as a matter of fact, I think 99% of cars do that and their fine.
You have pothole hitting + something loose in your car. As for why its happening to you, is a mystery.
Just remember your battery is in the trunk, next to your spare. if the connector is in tact, but you see corrosion, I would get a new battery, not always needed, but corrosion is usually the result of a weak battery. The cheapest place to get a 'good' battery is Sams Club, you can get an interstate battery for about $70. The cold cranking amps will be 590, its 10 shy of the original battery, but it should be fine, my interstate battery is.
Old Car: Chevy Cobalt 2006 LS Sedan base (Automatic)
New Car: Chevy Impala 2011 LT Fully Loaded (Automatic)
Last edited by johnccc; 03-15-2012 at 08:35 PM.