I have a 2002 mustang V6 3.8L. Recently it’s been overheating whenever I get stuck in traffic or have it running idle for a prolonged period of time. It makes a loud noice once it gets hot like a pulley is squeaking. But, the noise stops if I put it in neutral or if I turn the a/c off. I just replaced the water pump in it. Any ideas what the problem could be?

 

Sounds like fan is not kicking in to hi speed.