Just picked up my first Montero, haven’t had a chance to look into it, but what are your opinions? Pretty much everything in the front end was replaced or rebuilt per the last owner. It was drove about 1,00 miles then started making this sound.

 

Wow! That is loud. Sounds like the fan is hitting something? Is the fan loose? Is any of the plastic around the fan loose? Is the fan shaft solid? It could be the water pump. Has it been replaced recently? How many miles? Is the engine running smoothly? A broken/bent valve could also make a lot of noise.