Got a quick question about my 93 Lx 5.0, I changed the oil last week while the engine was still hot.It was only about 30 outside.When I put the oil in and started it up,the oil pressure wouldnt go up,and it started to knock a little.So I shut it off,and restarted it,the oil pressure went up and no knocks.The car only has 28'000 miles on it,could the oil pump be going?????Any help would greatly appreciated!!