Mystery sound in engine

Hello all,

Car is a 2007 infinit g35x with 270k on it

So the issue started a while ago, what happens is there is a rattle in the engine only under light acceleration between 1000-1200rpm while driving ONLY WHILE WARM does not do it while it’s cold or idling. This is accompanied by a “lug” in the engine almost a similar feeling to running out of fuel, it will lose power and lug for if I keep the pedal just ever so lightly depressed. This happens at any speed just as long as the pedal is just pressed lightly so the RPMs are around 1200 while it’s warm


I’ve changed the oil, checked every odd and end and even used an advanced scan tool which should no codes or any issues on live data.

My only thought is that during such a light acceleration the timing chain assembly isn’t getting enough oil pressure which is causing it to slap and rattle.

0 power loss other than that, runs like a dream other wise. No rattle during start up, it doesn’t do it while it’s cold, doesn’t rattle any other time…it’s a mystery

Brought it into a mechanic shop my buddy works at and they didn’t really seem to be able to replicate it since it has to be doing it while driving so diagnostic fees would be extremely high.

I’m quite mechanicly incline but this one has me stumped, I’m trying to sell the car but I don’t want to be scumy. I could change the oil to a thicker one but I’m not even sure it’s related to that, Any ideas?