Ok, I have noticed that there is a grinding in the front end of my truck when the gas is pressed in so far. I have no tach so i would say about 2200 to 2500 RPMs and higher. The grinding noise is coming from inbetween the radiator and the front of the block and about where the fan goes into the pulley. I first thought that it was the fan clucth due to the heat. Then i though it was the timing on the truck. it happens at all speeds and even in park and neutral. The problem did not start till about two months ago when the heat started to register triple digits on the temps outside. So anyone have any ideas what it is? its on a 94 4.9 2wd.

 

Check idler pulley and belt alignment.

 

Just a thought. Fan isnt hitting the raidiator is it

 

Checked all the pulleys and the alignment for the belt and they are good. fan is not making contact with the radiator either. The sound seems to be originating from behind the pulley like in the block.

 

Fan hitting the fan shroud, my older truck does it at certain engine speeds. The added heat from the triple digit temps may have caused it to change its shape just enough to hit.