Slight knocking sound

[silverWS6]

So I replaced the knock sensors on my 2002 Chevy avalanche and it all went fine just one small concern. After I was all done and I started it up there was a small knocking sound, it was there for about 15 seconds and then it went away and came back for about 5 seconds so I went in and accelerated a bit and then it completely went away and the truck sounds just fine now... So my question is what was up with the knocking sound? Was it because it sat open for 2 days and oil had to rise again? While it was open it was all covered up and no debri got in anywhere.

[blackSS01]

Could be from oil draining to the bottom but a good thing to check if you are 100% completely sure nothing got where it doesn't belong is take a short hose and put it to the oil pan. Listen carefully while someone starts the vehicle and listen for a lower end knock.