Oil Pressure Problem...

[BlueTA99]

hey was up! i have a 1999 Trans Am (Non-WS6) 6 speed manual transmission

everything is stock nothing is done to it but a regular K&N filter, other than that it is bone stock from the factory...

lately i been having an oil pressure problem...

at cold start the oil pressure is well over 40 ( im guessing 50 since its between 40 and 60)... n thats always at a cold start

now when im driving n warmed up, the oil pressure is at 40 (while im crusing)... but then after a little while, when im at a complete stop the oil pressure starts to drop little by little n the needle starts reading the oil pressure around 35... n then sometimes the needle starts bouncing from 35 to 39 back and forth (bouncing rapidly is that normal??)... when i start from 1st gear (regular driving) the oil pressure goes back up to 39-40... now lets say im doing 2500rpm on 3rd gear then i press the gas pedal half way i accelerate n it goes up to 4000rpm (still in 3rd gear), the oil pressure barely goes a little above 40...im guessing around 41-42 (i know its no more than 45)... and on top of that while reaching 4000rpm it starts to make a rattle noise (maybe my lifters or something from the valvetrain but i could/can be wrong)... the noise is pretty loud, i believe bcus of low oil pressure is wats making that noise (that its not getting enough lubrication) i could hear it from inside with windows up and down and is very annoying and personally it hurts me hearing that noise cus i feel that im screwing up my engine n now im afraid of going above 3000rpm...

but despite the noise n the oil pressure drop, the car is doing perfectly fine, i use my Trans Am as a daily driver to go to school and work n do erins, as long as i drive regular the car is good

my TA has around 60,000 miles, i dont know if the oil pump is acting up cus i hear that 1998-2000 models have bad oil pump, and i also hear that 1998-2000 that has over 50,000mile n having low oil pressure at warm temp. needs to change oil from 5w-30 (currently running) to 10w30 or is it my oil pressure switch???

so please i need help, opinions, advices, facts, suggestions or anything else please let me know...

i really appreciate you for taking your time reading this.

[2-bowties&abird]

i wouldn't worry unless it gets to much under 30. alot of people say it's still ok lower than that.