Can a VVT-i problem sound like an engine knock?

Anyone made any headway here? Dealing with the same issue and it's driving me nuts.

 

I had a bit of a valve clatter has first couple accelerations soon after cold startup, sounded like lifter noise or valve clatter and the truck felt sluggish, I chalked it up it getting tired but it's only got 150K and it's been taken care of.

Spoiler warning, this is a snake oil story but I think it might apply here.

During a PCV swap I noticed some crud buildup amongst the oil residue in the PCV, I decided to do an engine flush and I've been curious to try seafoam in the crankcase, it's petroleum based and reportedly cuts the crud pretty well. They call for an oz for every qt of oil the motor holds and put it in prior to an oil change, I decided to treat it 1000mi before the OC. Within a few days of adding the seafoam the valve clatter sound completely went away and since then (4K miles) I notice a subtle improvement in torque, it feels peppier in the 1K~2K rpm range and it no longer feels sluggish at all. Additionally driving back on the highway last weekend running on cruise in OD @ 70mph it shifted down out of OD on the hills about 1/2 as much as it used to. Overall the motor runs better, no noticeable improvement on gas mileage but it's never been bad in that regard. I've given it allot of thought since I started noticing these improvements and the only thing that makes sense to me is that the flush loosened up the crud interfering to some extent with the VVT operation. That makes sense since the vvt system is susceptible to crud as evidenced by the addl filtering screen. I never got any VVT codes but the flush improved the way my motor ran more then swapping spark plugs or doing a MAF cleaning. When I did dump the oil after the 1000mi it came out jet black, it's typically a dark golden semi transparent brown. It's anecdotal evidence but I'm sold on the flush as a mid-life motor treatment.