Well recently I've begun to slightly hear a noise at start up that sounds like a rod knocking but its kinda intermittent. Sometimes it does it for a few seconds and you can rev it a bit to around 2k rpm and the sound will increase with the rpm. It is not that loud but it sounds like what is normally associated with Rod knock. The blunt kinda rattle/clunk sound. Yet its rather quiet, you have to be right up on the motor to hear it, and you can hear it under the car a lil bit too. Its only when cold as far as I've seen thus far, and sometimes it'll go away as soon as it starts if it even does it at all. Then you can just hear the injectors tapping.

Any ideas maybe?

EDIT: Currently running Mobil 1 just changed 2 months ago with under a thousand miles on the change so far.

EDIT: oh and one more important note, Oil pressure at cold start is about 60-65 and after heating up works its way down to the normal 38-40ish at idle and around 45 giving it gas.

 

Bad lifter, exhaust leak? Possible stuff...

 

If its rod knock it will be a deep frequency knocking sound, could also be a main bearing or two.

If its a ticking look at exhaust leak or lifter. If its really a knock then it will get worse and become very obvious.

 

It could very well be an exhaust leak or a lifter...