When my car is under 190 my engine makes a loud noise when accelerating. once the engine gets to normal temperature the noise lowers greatly but its still there.

 

Possibly water pump bearings. They do expand when hot. Grab your fan and try to move it up and down, left to right. There should be NO movement of the water pump shaft. DISCLAIMER!!! Do this with the engine OFF. I just KNOW someone is gonna try it with the engine running!!