Good day everyone. Here is the story. 95 Silverado 350. Just came from the mechanic for a new catalytic converter to pass Texas State Emmissions. Two days later it sounds horrible in the driveway; I check and no oil on the dipstick. No smoke, no leak that I can tell. I add about 3 quarts of oil back but the horrible engine sound doesnt go away; I look and there is no oil pressure. This was a few weeks ago and it has been sitting. Today I fire it up one more time for grins to see if it will work before I start jacking it up to work on it. I gunned the engine a couple of times, and lo and behold the gauge pops right back up and the engine starts to purr. Well purr is relative with 260K miles, but it sounds fine. Took it for a little drive and all seems well. Question is, did the oil pump have to prime or something that it just wasn't doing at idle? Will it probably be alright now, or should I keep an oil pump change in the plans? I will do a full oil/filter change this weekend with 4 quarts of Castrol and a quart of Lucas just in case. Happy Easter everyone.