Car has a knocking noise on 1998 Chevrolet Monte Carlo

My 1998 Monte Carlo z34 has a knocking noise coming from under the hood. No one knows where the noise is coming from. The car does not lose engine compression but dies out while rolling down the street. In order for it to start again the battery has to be recharged. I dont have a battery or service engine light come on. Can anyone tell me what it may be?

Asked by for the 1998 Chevrolet Monte Carlo
Have you had the alternator or charging system tested. Would have to hear the knock.
Havent had a chance to test the alternator but i will do it today.
Battery shouldn't run down if it's working.