intermittent loud knock from engine compartment
 

Over the last year, on only 5 or 6 occasions, I've experienced a very loud knock coming from the engine compartment, which goes away after less than a minute. It happens (seemingly) only at low speeds.

The last two times it happened I kicked the accelerator down for a second, and this caused the noise to stop.

Context: I run on WVO, and I'm overdue for a valve adjustment.

Could this be an IP noise?

An engine knock is not good what is good is that it goes away if you kick the accelerator down but the problem is probably not fixed and it will happen again when it does you will have to establish more closely where it is coming from. Last knock I had from my last engine happened because the bottom of my prechamber blew out down into cyl. and had to pull engine. If the knock happens again as it is knocking you could loosen 1 injector line at a time to see if it is coming from a certain cyl. Also try to determine is it coming from upper or lower part of engine.

In the event that you fancy yourself as being St. Peter, it may be caused by Bob Dylan.