When i start the car up i hear a bird chipping noise coming from under the hood. It only happens when i started the car up and when is accelerate>
Have the tension of your serpentine belt checked.
One of the accessory drive belts is loose. Adjust the tension and the noise should go away.
You may need a new belt to completely solve the problem.
Just put all new belts on it
Maybe one of them isn’t tight enough. I’m having the same problem on my Legacy. New belts, but every once in a while, usually when the weather is wet, the alternator belt will squeal on start-up. It’s annoying, but nothing I’ve tried stops it.