mtwieder

I have a 98 ls1 6spd. I've had a problem past few months where i'll get a light tap in the valve cover if the oil pressure dropped below 35-40psi roughly but the tap typically only came at idle and as soon as throttle was applied it went away. I was concerned that it could have been the oil pump. the car does use oil, it has high mileage, and i run 20-50. other weights and synthetics seemed to have the tap happen louder and more often. However i have had no problems with the tap since the weather has warmed up. But the problem today was while i was driving my oil pressure dipped below 20psi and at times lower than that. so i checked my oil and noticed a few things, 1.the oil was extremely low (i was planning on doing oil change this week before this even happened) 2. the oil smelled like gasoline and 3. there's moisture in the oil as well judging by the residue on my oil cap. i added a quart of oil so i could get it home and kept an eye on my temperature gauge and oil pressure. on the drive home my oil pressure increased slightly to 25/30 and my temperature was consistant at 180-185 thru driving and idling. But if i took it about 2500 rpm i could here a knock/tap different than the one i used to get in the valve-train. I'm in need of any info possible on what could be my problem so i can begin a more thorough diagnostic procedure. thanks guys!

Old Geezer

iTrader: (3)

Cut the oil filter open when you do the change.
Gas in the oil could be from blow by. [Hi miler and using oil.]
Noise moving lower can well be bearings on the way out, pistons slapping the walls.