I have an engine knock in my 04 holden rodeo with the 3.5l petrol 6ve1 engine. Seems to knock on idle dissapears with acceleration.(or just gets muffles by exhaust noise) any help on attempting to diagnose it would be appreciated.
When it comes to engine knocks, I like to verify the worst possible scenario 1st, and that is rod knock. From a professional view, if this is the cause of the knock, depending on the value of the vehicle, is a game changer for a lot of people.
With the vehicle running and knocking, disable spark from each cylinder one at a time. If the noise suppresses on 1 of the cylinders, then it is rod knock.
By disabling spark, you are changing the force from driving (piston moving the crank) to driven (crank moving the piston) and there should be a definite change in sound if there is a major problem.