I recently just put an old 20r I got from a salvage yard into my 76 toyota Chinook. Everything is running just fine on it except I'm getting a rocker arm knock. I checked my oil the last couple days and my oil is spotless (like I just put it in) even after a 170 mile trip. Any ideas what could be happening? I was thinking maybe oil pump is failing or something clogged. On the trip I took the temp was good the whole time except for the knock.

 

Do a valve adjustment.

 

Your 20R has an overhead camshaft. No rocker arms involved. I’m with jetas, if you’re getting noise, check your valve clearances.

 

Also make sure the valve cover isn't too tight or the rockers may touch - dunno if the 20r has this issue, but the 22re does.

 

20r valve covers are much higher, thats why folks like me who switch to ARP head studs like em. It is worth checking valve lash, but also the torque of your head studs. I ended up with bad rocker rattle when one of my head studs stripped out of the block.

 

Thanks guys for your help! Solved one of the issues. It was the valve adjustment. I knocked them down to .007 and .011 and that seemed to do the trick. I'm still having an oil flow issue. Its really strange maybe ya can help direct me to the right thought process here. I'm still getting a grinding issue in the back of the engine(I thought it was clutch or transmission). The oil that the dipstick reaches is still spotless oil. Thats sitting in an original 20r engine that has been sitting at pick nnpull yard for who knows how long. I drained a little bit which was a good healthy dark colored oil, oil filter is getting oil to it, but when I took off the valve cover I noticed the whole left side of the top of the cylinder head had little to no oil. I ended up pouring some oil in the back left oil port of the cylinder head just to see what would happen and the grinding(which I'm guess is a set of bearings grinding) went very quiet! So there must be a blockage right or maybe the oil pump going bad, or clogged oil pump catch in the oil pan? Would anything like this make sense. The temp is running good on it for the most part but that grinding is worrying me.