knocking sound from engine

I am sure it is a colapsed lifter - two nights ago the wife arrived at my shop with the tb rattling. I had her shut it off, after a moment I checked the oil, it was full but dirty. the next morning I started it and no sound, after about ten minutes when it warmed up the knocking came back (more like a loud ticking). I changed the oil with no change. It did this all day. This morning I started it and again no noise for about the the first ten minutes. I added some Luca oil to the system and let it run for 20minutes with no change. It maintains 45 oil pressure at idle and slow run and over 60 on hard run.

If it is making a noise dope is not going to fix it.
You need to get a trained repair shop to listen and check it out.

Well, second day of no noise. The dope worked again. Rember folks, the best advice to everyone on every type of auto and equipment. Regular maintenance saves worry and money. Oil, filters, and air filters are cheap compared to engines. 90% of all failures are do to poor maintenance, not factory mess ups. I am the worst and know this, as the old story goes. The mechanics cars are always the last to get worked on.