There is a growling noise when I put my key in and turn it to acc, but I don't start it, its not really loud then after like 20 seconds it stops, also when my friend gets in the car its starts again...someone help me.....

Sounds like the air coimpressor... Lift the hood and stand by the front drivers side door. Listen to the area under the windshield washer tank. Have a friend turn the key to the acc. If the growling comes from under the washer tank, it is the compressor turning on and attempting to fill the air bags. It will stop after a certain amount of time, after 60 sec. if the air bags are leaking.

The compressor will only turn on once the rear ride height has lowered from the factory settings. So when your friend gets in, the car lowers a bit, thus turning on the compressor.

These are normal operations. Usually the compressor is silent, and you may have either a compressor that is going bad, or it is rattling against the mounting bolts...