My uncle has a montero sport with a 3.0 and it has an EXTREMELY loud noise at about 1200 rpm. When you first start it there is no noise until it warms up and engine rpm's decrease you hear it. Sound as if its like a fan hitting something but thats not it, It sounds like its in the front of the engine maybe a water pump? Its not leaking antifreeze that I know of. Thought I'd ask you mitsu guru's for a little advice thanks.

 

bump to the top

 

bump again

 

What's the engine model that is in your Montero?

Also, a video would probably help

 

It says 3000 v6 on the plastic engine cover

 

6G72 engine. Could be a lifter problem. Worst case bearings

 

I think I narrowed it down to a hydraulic timing belt tensioner, wish me luck