Originally Posted by
anyonebutme
if the pump intake pipe cracks or falls off (seen it), boom, no oil pressure at all. if the oil pressure relief jambs open (seen it), boom, little to no pressure at idle. if your center main bearings get smashed you'll also get no oil pressure at idle, have a car out back that suffers from that specific ailment right now. Oil pump gears breaking tend to take the front main seal out at the same time and dump oil all over, but I guess it's possible for the outer gear to come apart and not blow the seal, just never seen it on a 6G.
i personally would just go ahead and pull the pan, it's not a difficult job and will answer a lot of questions immediately. after that it's not a difficult job to remove the oil pump.