Altima Making Squealing noise

[02Altima3.5]

Hi my 02 altima 3.5SE is making a squealing type noise when I accelerate. At first I can hardly hear the noise and my oil was leaking and my oil was really low and the noise was much louder and after I change my oil it went away and I have another leak and and the noise came back and I had to change my oil again and it went away I thought it made the noise because the oil was low and I just replace my oil cooler O ring because it was leaking and I take it for a spin and the noise is back. Seems like the noise comes and goes and I don't know what is wrong with the car. Can someone help please