I'm getting an engine knock that you can just hear at idle but is louder as you put the engine under load. There is a rhythm as you increase the revs under load but doesn't do it when you decelerate.
The engine is also idling just on 1k.
Thought it was the exhaust manifold but replaced that and there are no leaks.

Is it detonation ? Which can be catastrophic on motor!
Can be many things.. Even engine mount..