What could this noise be?

2018 SR5 V8. Cold start, when I started the truck there was a knock/rattle noise coming from under the truck. Transmission area. definitely noticeable. Sounded almost like engine knock. Lasted about a second or two. I turned off the truck and started it again. No noise. Truck is driving fine, no lights or anything weird. I will wait for the next cold start and try and record it. I know it’s difficult to diagnose from my description. But was wonder if anyone else had similar occurrence. I’m leaving for a road trip tomorrow so I’m a little paranoid.

 

Your fine I've had that issue myself and apparently it's a normal thing until the oil pressure builds up. Even I myself can't see it being normal but hey that's what the Toyota techs say

 

Thanks for the reply. It hasn’t happened since. Hopefully it dosnt do again.