Just did a head job, replaced the lifters, and while test running with the rocker cover off noticed one valve/rocker assembly wasn’t moving. Went back in to make sure the rod was installed properly and to inspect the camshaft. I have no experience with camshafts, but the camshaft lobe in question seems to be more worn than all the others, not flat, just not as pointed. I should mention this wasn’t an issue before the head job. Do I just need to get an adjustable rod for this lobe?

***UPDATE***

manually pushed on all the rods on the driver side and all of the hydraulic lifters were stiff except for the lifter associated with the non-moving rocker/valve. That one was very springy, I’m guessing it’s not filling with oil and isn’t getting stiff.

***UPDATE***

pulled out the bad lifter to discover what’s shown in the pictures below… any ideas how this happened? There is not supposed to be a hole in the bottom of the lifter.

 

If that is a brand new lifter you have some serious issues. That thing is no longer flat and badly worn down (explains the hole thru the bottom).

 

yes it was brand new as were all the lifters. I’ve chalked it up to you either some sort of break-in issue with the lifter becoming stuck or possibly installing a rod incorrectly to the point where the rod was pinning down the lifter and not engaging the spring/hydraulic cup. It looks like the cam is slightly worn and I’m planning on replacing the cam in the near future, but hoping replacement of the lifter with zinc additive to the oil and assembly engine oil around a replacement lifter will get things moving.

 

Looks like the lifter was not able to move up the cam. Either stuck in its bore, or the valve is stuck and not opening. Can you open the valve?

 

I figured a stuck valve wasn’t likely due to them being vacuum tested and seals changed. What’s the best way to get the leverage to test a valve?

 

I would anchor a loop of wire (e.g. from a coat hanger) not too far from the valve (maybe use a rocker shaft bolt as the anchor), then use a pry bar (or long screwdriver) on a block of wood to press down on the valve. Or simply tap on it with a hammer to compare the bounce with other valves. Intake and exhaust use the same springs, so they should give the same feel.

 

So, I swapped out the lifter, made sure it was good and oiled. Tested with the rocker cover off and everything was working. However, I still get a lifter noise, the same lifter noise that was present before this previous lifter failed. I can’t get past the idea that the same thing is happening to one of the other lifters…. But all these lifters are brand new from Atlantic British.

 

Engine noise can be difficult to narrow down (many noises all at the same time in close proximity). The noise that bothered me (that I thought was lifter noise) turned out to be a small vacuum leak between the upper and lower plenums (in the same neighborhood as the valves). Small exhaust leaks can also sound like valve train noise. My mechanic uses a hose held up to his ear to help pinpoint noises, and puts a short length of brass tube (like a straw) in the other end.

Since all your valves are lifting properly, I'd say you cleared that hurdle. A little noise is OK, a lot is bad, I don't know what else to say. I bought new lifters, but there seems to be one that just takes longer to quiet down after the first start.

I read about a troubleshooting technique to put a feeler gauge (very thin, 2 mil maybe) between valve stem and rocker while engine is running (covers off). If it gets quiet, then you found the culprit. Never tried it myself. Sounds like it takes touch. Maybe worth a try.

 

had no idea vacuum leaks could be causing a lifter like noise. I do use a stethoscope with a rod on the end to isolate noise. After replacing the bad (new) lifter I isolated a new spot on the same side that sounded like it had a loud lifter noise. So this morning I pulled the spark plug that would supply that lifter and the sound remained completely unchanged. However, now I’m not sure if pulling that spark plug should have stopped the lifter noise because the camshaft is still rotating and hitting that lifter?

Also, I noticed that this “lifter noise” isn’t present on startup, but slowly develops from start up

 

Pulling spark may isolate noise from a piston/connecting rod, but not the valves.

Engine parts expand when heated, contract when cooled. My engines sound off for several minutes after a drive. I think the interface between the aluminum exhaust ports at the head and the cast iron exhaust manifold is the main source, since aluminum and steel expand at different rates. So, it could be an exhaust leak develops when hot, but is fine when cold. I have multi layer steel gaskets now, but wonder if fiber type exhaust gaskets would be quieter.