Are you 100% sure it is just one rocker? You might have something wrong that you just cant see. broken spring, retainer, even something like a bad or missing keeper (as crazy as it sounds) I would remove the keepers, retainer, spring, and check for wear in the guide, basically anything with that one rocker if you know it is that rocker. If you don't see anything wrong, I would swap that stuff to a completely different rocker on the other side of the engine, and see where the noise ends up. Also check the preload for that valve. Did anyone ever change a lifter?

 

I just changed all the lifters ( to stop "the bleed down problem") & still same problem same side. Just started it up again & got it realy loose(ticking loudly) & killed it the intake lifter in #1 is blead down, there are others that are a LITTLE spongy but not like this one & now my oil psi is low so... now I'm thinking i'm loosing oil psi starving the top end ...just have to find the wear spot or pump?? but thinking cam bearings??
will the lifters stay pumped up the same ( in a perfict world ) or will the spot it is stopped at in the lifter boore come into play as far as bleeding back down some?

 

.120" clearance between valve & rocker (when you push down on the bleed down lifter )& yes the decimal is in the right spot!

 

I will bet you $ it's your oil pump O ring sucking air. It bleads thru the lifters and makes them tick bleed down etc. I just went thru this on a 06 6.0L.

 

what o-ring was it on yours & what symptoms did you have?

 

same symptoms I got the engine given to me because no one could figure it out and the customer ended up buying a new engine. I swaped cam, rockers, pushrods, and springs before I put it in my truck. Once i got it running it would start a terrible clatter after a few miles of driving. Shut it off and it would go away untill you ran it up over 2k rpm for 30 sec or so. I got it ticking shut it off l, pulled drivers vc and lifters wernt pumped up. Ended up pulling head and swapping lifters on drivers bank. Drove it and same symptoms! I then started looking at a 6.0 block and the oil passages finding the lifter gallery is highest point in the oil system, and the left lifter gallery feeds oil to the cam, main bearings, and oil psi sensor. Being I had oil psi I knew air was the only culprit. Those orings have been known to fail, so I pulled the pan, and pickup and found oring hard and shrunk up. Replaced it and problem solved along with another 20psi in oil psi. To change it you just drop the pan, and pump pickup. Ring is located on pickup tube where it enters the pump. Took me 2-3hrs to change it. Mine is 4x4 so I had to drop down ifs.

 

Good info from you dude. Im willing to bet you just solved alot of peoples problems

 

very good info ...I only wish I thought to post up earlier... I knew the lifters were bleeding down, Just assumed w/ 150k it was just time I couldn't believe it when it started again ...I even went the extra mile & pulled other head to do all of them!
THANKS

 

I called that **** yesterday

Hope it works out for you

 

I think it's the oring but you could be right also. A cracked pump housing could act similar. We will have to see!
Most of the time people change the oil pump, and o ring but the o ring was their problem. A while back I built a 6.0L short block for a local shop, and they put the rest of the engine together. It had erratic oil psi, and noisy valve train. We figured the oil pump bypas was the problem so pump was changed along with the o ring. Problem was solved, but they also happend to replaced the o ring they had reused! I ended up with the new 50 mi pump they took out