Got my own thoughts and want someone to tell me I may be wrong or tell me I may be right.
engine 145,000 miles started knocking and rattleing
took it to mechanic he pulled valve covers and whole intake. Said it was so gummed up on back side lifters had rust on them. He replaced 2 rocker arms, rocker arm shaft they were either stopped up or ovaled out.
he changed oil twice and put pure transmission fluid in it to clean it out. Replaced it all. Van run like a top.
said to come back and change oil every week for a couple weeks. Drove 240 miles went back and changed oil. Had to go on an emergency trip out of state. After 200 miles top of motor started alot of noise again, this time much worse. Happened to be at a sears had them change oil again 3 quarts oil 1 1/2 quart trans fluid. Turned around and headed home.280miles. Now van is quite for the most part but then will start knocking again. My question is all the sediment that the transmission fluid loosened up had to go to bottom of motor. He didnt pull pan just changed oil. Could it be screen stopping up or oil pump half the time working and should I clean or just replace both. Any suggestions would be appreciated. Thanks ricky