ok, today I went to someone'e house in my neighborhood. I left the engine on with music playing. I turned that off then tried starting it after 5 minutes and it wouldnt start. So i finally jump started and it started just fine. However, this battery is like 6 months old. I think i bought it in march or april. I left the car running for 30 minutes and it starts now however, I hear this sound now. Its kind of like a cranking sound but much louder.
The battery has 800 cranking amps and 640 cold starting amps. I bought it from costco.

 

It could be the battery. Have the charging system and the battery tested for their ampere output.

 

new parts are always suspect when a failure occurs after the new item is installed, but go some place where they will check both the alternator as well as the battery.

if you have a voltmeter, check the voltage after the car has been started but without any extra things on such as headlights, radio, heater fan, etc. voltage should be about 14.3. turn on the headlights, brights, heater fan and the voltage should stay above 13 and depending if the battery needs a charge at this time, the voltage should go up as you increase engine rpm above idle.

 

well like yesterday it started with no problems. However, now when I start I get this cracking sound.

 

Get a multimeter check your voltage with the car running like previously stated. It should be over 13 volts when the car is running, if not your alternator is on its way out or already dead. Make sure the voltage is consistent.