rodeo knocking noise

[skeeta1]

Hi Gents ,i have a rodeo 2001 v6 3.2 petrol ,and am getting a noise coming from the front of the engine,is like a knocking ,but speeds up when i rev it ,it doesn't happen all the time ,but is definately getting worse over the last couple of weeks ,without actually pulling stuff apart i am stumped as to what it is ,the engine has done 225000 kms and pretty sure it hasn't had the timing chain done ,so i am thinking along them lines ,any insight would be great