Engine noise

[smkymntn]

So I just changed my oil this morning. after I refilled and re-started I was checking underneath for leaks- I heard what sounded like something grinding in the oil pan. I stayed there until the truck warmed up and then it got fainter and fainter and finally going away. Is it oil starvation from the oil change or is my motor on its way out? It is a 99 4runner 2wd, 5VZFE v6. Truck has about 133k and runs as smooth as silk. I have never really listened to truck run in that position before and think I may just be a little paranoid. One more thing- oil leaking from engine and trans connection would more than likely be rear main seal correct? Is it a pain to do on these trucks?

Sorry for all the questions- any help would be appreciated.

[ECGS]

most likely rear main but could be coming from higner up and draining down, pain, i guess the tranny has to come out.

i doubt there is anything wrong with the motor at 133k unless it was severly mistreated. could have been a noisy bearing from water pump or an accesory pulley.

keep an ear on the noise if it seems to get worse have it checked out.

[smkymntn]

I bought it with 54k. All maint done by me, run synthetic, never beat on, used to tow or abused in any way.