Hey all got a question for my 98 d1 V8 148k

Just did diff+ t-case fluid change and an oil change Valvoline vr1 w/zinc 10w 30

im now getting a knock on start up on cold days (in the northeast). Oil light stays on for 3-5 seconds after start up then is gone. Knock Goes away in about the same time. does this sound like Rod knock or a main bearing or something? Figured id post here first but the temps have been well below freezing on these days and ive never heard it before this haven't driven it much since it started happening but no other drive ability issues

 

What filter did you put on it and it’s possible that a 5w40 might be a better choice in the cold climate.