Is my oil pump failing?

Car is a 95 Eclipse GSX and it starts loosing oil pressure at idle when the engine starts to heat up i guess da oil losses viscocity and itz harder for the oil pump 2 push the oil up into the engine. Once i get into higher rpm's ther is a very loud ticking/knocking noise that kinda sounds like a loud growl. I am not drivin the car right now!!! The noise is on the side where the oil pump is so i kno itz not rod knock cuz the noise isnt in the engine jus the side where the belts are. I want to kno if the oil pump is failing oh and the noise only starts wen we start loosing oil pressure thnx !!! DSM 4 Life!!