Any stone chips, fractures or deep scratches in the finish should be repaired right away. Bare metal will corrode quickly and may develop into major repair expense.
Minor chips and scratches can be repaired with touch-up materials available from your dealer/retailer.
Larger areas of finish damage can be corrected in your dealer's/retailer's body and paint shop.
Chevrolet Cobalt Owners Manual. Checking Things Under the Hood
WARNING:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
WARNING:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant ...