Not sure who else out there experiences this but with my 4.2L, I get a knock when at low RPM and giving it pedal. In other words the revs before a possible kickdown or higher RPM.
Seems like something that shouldn't ordinarily happen and I do not think it was the case when I first bought the car used about 4 years ago?
Only lasts for a brief period too. If the car kicks down, the knock is either dealt with by the ECU or the revs are up enough that I can't hear it anymore.
If the car doesn't kick down, the knock disappears as soon as the RPM's pick up.
Can't really tell with live data what the ECU is doing at that moment but clearly - the engine is asking for additional fuel and not getting it for whatever reason.

Ideas?

 

It is a sign you are running high trims, but not quite high enough to trigger the OBD code. You need to get these trims back down to, say, less than 5%. A code triggers at 25%. I had the same knock/ping going uphill in fourth gear, low rpm, and giving some gas (not enough to downshift). My trims then were around 15%. I replaced a bunch of dried o-rings and both VVT seals, which brought trims down. Threw in a new air flow meter (ours are cheap) for good measure. Best is to do a smoke test to identify all leaks at once.

Best of luck, keep us posted.

PS: get a cheap ELM327 scan tool to read the trims if needed.

 

Thanks for the intel.
Yeah, been tracing leaks - both vacuum and false air since the day I bought the car lol.
I have a smoker and it currently is not revealing anything obvious.
All new cam cover and vvt seals. There are new seals just about everywhere aside from pulling the intake.
I have the JLR software and use it regularly and my trims are not that bad but maybe they can still be bad enough to cause the detonation.
Still running the same MAF though. Haven't had any codes on it and it seems to be working as intended.
If I discover anything new I will certainly post back on the subject

 

Keep in mind the trims are a function of load and rpm. You really need to "capture" the trims as you are on/near knock conditions.

 

have someone who can hear the knock in the passenger seat watching the fuel trims. Helps if you have a scanner that can mark a data point by a user for later review.

a really good way to find leaks is with an unlit propane torch. On other cars it helped find a few hidden leaks.