I just changed the lifters on my 4.0 1997 XJ. Everything is put back together but the valve cover is still off and I have not yet started the engine since reassembly. Pretty much every rocker arm is loose even tho they have been torqued to spec. Is this normal until the motor builds oil pressure?

I used Melling JB-2011 and soaked them over night in fresh motor oil.

Thank you.

 

No, that is not normal.

https://www.cherokeeforum.com/f2/how...h-rods-257311/

 

Thank you for the info.

 

Yes it is perfectly normal if this is before the first fire off of the engine with new lifters. The lifters have not had oil psi run through them so they are not pumped up yet.

 

This is a nice thing to hear, kinda what I figured but who am I (deff no mechanic). I did set each cylinder to TDC on intake stroke before installing rocker arms torqued them to 21' lbs.

Thanks for the reply.

 

uh, if you need to pump up your hydraulic lifters prior to adjusting the valves, you have serious issues... The spring inside the lifter holds the plunger tight at 0 lash; there is no need for oil...

 

What would some of the serious issues be?

 

My apologies for exaggerating a bit. I saw that response and ....

If you need hydraulic pressure to pump up the lifters to full height, then they are either worn and sticky and will bind-up sooner or later, or if new, they were assembled with the wrong spring. If you need hydraulic pressure to pump the lifters up to full height, it's going to rattle like a SOB upon startup. If you don't have preload on the lifters, aka where you're at now, it's going to rattle like a SOB all the time...

 

I don't have much to share on torquing rocker arms, but I did just get a new motor back from a builder. With no oil in the motor, and no oil pressure what so ever the rockers were tight. I could move one of them, but it was tight like it was pushing the lifter down. After I primed the oil pump I couldn't move it anymore.

How loose are you talking? Like rattling loose?

 

Well yes, if the plunger isnt all the way up out of the box, thats a different story. But the OP sounds like he is stating that he can push the plunger down by hand (by pushing on the rocker after being preloaded). The spring helps push the plunger back up when there is no oil psi in the lifter, thats it. Fresh lifters you can easily push the plunger down, all the way down (and should come back up on its own). What do you think is stronger, the valve spring or the spring in the lifter? Ever heard an engine run with no oil psi? They are super loud because the lifters are not pumped up and you are hearing them bottom out.

Preload is set to get the plunger close to the middle of its travel limits. A typical lifter plunger has about .200-.250" of travel. Therefore, you would typically set preload anywhere from .080-.120" down (depends on the lifter brand and travel of course).

 

6 to one half, half dozen to the other...

By loose I assumed the OP meant like loose, moving around, not tight. If they meant that they could be pressed down, then that's a different story, as you said...

 

Just went out and pulled the valve cover off my spare engine and the rocker arms could be shifted side-to-side along their pivot axis by maybe 0.015", but otherwise they were "tight" in every other direction. The pushrods spin rather reasily.

 

Ahh that makes sense now.

This also makes sense since the engine has already been run and has primed the lifters.

 

So here is where I am at.

I loosened all the rocker arm bolts, then I got cylinder 1 at the TDC of the compression stroke, then I snugged both bolts evenly and eventually to the torqued spec. I did this with all six cylinders in the firing order.
There is no looseness in the up and down movement of the rocker arms other than the plungers in the lifters being soft. All my movement is side to side play which sounds kinda normal but I would like confirmation on this.
Maybe I am just being over cautious and I should probably fire this thing up. Also upon further research it sounds like it is normal for the plungers in the lifters to be on soft/spongy side until they are pumped up with oil pressure.
What do you guys think?

Thanks to everyone I appreciate all the feedback.

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Honestly, good for you being cautious and asking questions. Now stop messing around and fire that thing up!