My car started losing oil really bad from the front of the engine. It got to the point of the lifters tapping, but never knocking. I went in and replaced the front main seal. When it pulled it into the garage, it wasn't even tapping. After putting everything back together, I start the engine, and it sounds like there is no oil in it. I have oil pressure at about 3/4 of the gauge at idle. In replacing the seal, I did not pull off anything that had a gasket on it, i was able to pull the old seal out by hand.