2003 3.4L cold start noise - piston slap, or..?

Greetings. 3.4L V6 here with about 240k. No oil burning or excessive consumption issues, currently running Mobil 1 5W-30 and have since I've owned the truck.

I'm familiar with the typical 5vz-fe ticking noises, but over the last couple days I've noticed a new sound that only happens on cold starts when cranking and shortly after. It's sort of this faint metallic grumble, but loud enough to hear from in the cab. It dissipates within seconds once the truck is idling. It's kinda hard to hear in the video and this isn't the most noticeable example, but you can hear it when the engine is cranking just before it starts. I don't hear or notice anything strange while driving. I did a little reading here and saw some mention a clogged cat as a possible cause, but I don't think that's it. If it were a cracked flexplate, the noise would continue while the truck idled, right?

I'm thinking/hoping it's just piston slap, what do y'all think? Or maybe i got some bad winter gas and the truck is grumbling about it? That's about the only variable I can think of that's changed recently. I'm not too worried about it but figured it was worth getting some opinions on.

 

Did u ever figure it out

 

I think it was oil filter related. I was using a Mobil 1 filter; swapped it out for a Toyota one and the noise stopped, so I think the anti-drainback valve in the M1 filter must have been faulty. Sadly, my truck got totaled by a texting driver shortly after I made this thread.