Today i started my car and drove around a bit. when i got home i revved up the car to 5000rpm and there was a sudden noise, so i turned off the car. When i wanted to start the car back up i would start at all it would crank but not start.. I checked for codes and it didn't thrown any codes. Once i let the car cool down a bit it started up normal but after revving it the screeching noise start again and it seemed that it was coming from the water pump. I seem to think that it the water pump. Anyone else has any other suggestions??? that would really help.. Here is a video of the noise: camaro z28 LT1 Noise from water pump? - YouTube

 

Use a stethoscope to verify.

 

It can also be the bearing in the idler pulley or belt tensioner making that noise. They do sound like that when they're bad. Take off the belt and spin the pulleys by hand, with a little side loading to see if you can isolate it.