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16 hours ago, cruiser54 said:

so, you can blow through the pushrods easily? 

I just finished taking out each pushrod, and blowing them with the air compressor.  They are clear (which makes sense, since the pushrods were new when I installed the head 18 months ago.)

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1 hour ago, cruiser54 said:

One more question. Are the pushrods that aren't delivering oil, are they the same length as the other pushrods?

I did not MEASURE them, but I inspected the ball ends for signs of wear, and saw none.   When I stand them up on a hard surface, the heights are within 0.005" of each other, roughly.

 

The pushrods I put in were new Melling ones, from Rock Auto.

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that's what I was wondering.

 

so now, lifters? Cam?

 

confirm this. When started cold and there is the tap noise, if you turn it off and restart it, the noise is the same. Not better or worse. 

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57 minutes ago, cruiser54 said:

that's what I was wondering.

 

so now, lifters? Cam?

 

confirm this. When started cold and there is the tap noise, if you turn it off and restart it, the noise is the same. Not better or worse. 

That is correct.  When I start it cold, there is no tap.  After a couple of minutes (no more than 5), the tapping begins.  It "peaks" and remains constant until the engine is VERY warm (and you know what "warm" means in PHX.)  

 

Once the engine is really good and hot (temperature guage has been at 200-210* for more than 15-20 minutes, and idle oil pressure is now about 20 psi), then tapping sound is "almost" gone.  If you listen CAREFULLY, you can hear it, but its no where NEAR as obvious as when in the "warm up" phase.

 

Even my wife commented on the tapping in warm up phase, but she could no longer hear it on a hot engine  (but I knew what to listen for, and detected it FAINTLY when hot).

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I am skeptical of the cam being trash, and here is why:  I know that many guys feel the older flat tappet cams don't do well with modern oil, but I never had any issue with it on my two XJ's, both of which clocked over 100K on them.

 

However, when I pulled the lifters to clean them when I put on the new head, they were RASTY.  What I mean is they had varnish on them that was so bad, I had trouble removing a few with the lifter "slide hammer" gadget.   After I got them out, they were just plain gunky on the top side, and I did my best to clean them with acetone, and then soak them in ATF before reinstalling them.   The bottoms of the lifters where they ride on the cam were flat and smooth.  It was obvious that they were still turning as desired, with no wear patterns showing.

 

I almost think my "cleaning" of them may have actually made one or two of them MORE problematic, especially since I did not disassemble them in any way.

 

In retrospect, I should have ignored the old adage about not putting new lifters on an old cam, and just replaced them all.

 

This is me postulating (hoping?) that the issue of cruddy/semi-inoperative lifters is the source of my noise....

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43 minutes ago, AZJeff said:

I am skeptical of the cam being trash, and here is why:  I know that many guys feel the older flat tappet cams don't do well with modern oil, but I never had any issue with it on my two XJ's, both of which clocked over 100K on them.

 

However, when I pulled the lifters to clean them when I put on the new head, they were RASTY.  What I mean is they had varnish on them that was so bad, I had trouble removing a few with the lifter "slide hammer" gadget.   After I got them out, they were just plain gunky on the top side, and I did my best to clean them with acetone, and then soak them in ATF before reinstalling them.   The bottoms of the lifters where they ride on the cam were flat and smooth.  It was obvious that they were still turning as desired, with no wear patterns showing.

 

I almost think my "cleaning" of them may have actually made one or two of them MORE problematic, especially since I did not disassemble them in any way.

 

In retrospect, I should have ignored the old adage about not putting new lifters on an old cam, and just replaced them all.

 

This is me postulating (hoping?) that the issue of cruddy/semi-inoperative lifters is the source of my noise....

:applause:you just learned from your own experience and solved your current problem. replace the lifters and enjoy your day. :L:

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I don't think your cleaning caused any issues. I think 2 lifters still have some crud in them not allowing oil flow. How long have you driven it like this? 

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Would it be worth trying to disassemble the two questionable lifters and give them a thorough, internal cleaning?

 

Probably not, but it's a thought. That would make more sense on a 2.5L, where you can remove the lifters without disturbing the head. On the 4.0L, if that didn't work you'd have to pull the head again. Ugh!

 

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I agree about not trying to clean the lifters - stock lifters are only, like, 4 or 5 dollars so I don't think it's worth it to try! And there shouldn't be any worries about new lifters on an old cam, as long as oil with a proper amount of ZDDP is used.

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6 minutes ago, cruiser54 said:

If it were mine, I would try some other things first.

Does the Jeep have a tachometer in the dash? 

I have a tach in the machine.  As far as cleaning lifters, since I have to remove the head to remove/replace a lifter, I would spring for a set of lifters.

 

what other ideas would you suggest?

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Adding a quart of Marvel Mystery Oil and running it hard. 

I've had good results holding a warmed up engine at 4,000 RPM for 3 minutes with the MMO in the crankcase. 

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13 hours ago, cruiser54 said:

Adding a quart of Marvel Mystery Oil and running it hard. 

I've had good results holding a warmed up engine at 4,000 RPM for 3 minutes with the MMO in the crankcase.

Agreed. Its a Jeep. The more you beat it like a redheaded stepchild the more it likes it.

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So I decided to bite the bullet and put in new lifters to accompany the (relatively) new pushrods, rocker arms, and rocker pivots that I installed when I put on the new Clearwater cylinder head about 5,000 miles ago.

 

So here is my question:  I will be using engine assembly lube on all the parts as put the engine back together.  I will also be switching to Rotella 15w40 upon reassembly, and I will add some ZDDP supplement to the oil.   But...do I need to do any special 'run-in' procedures with the new lifters on the old camshaft?

 

Back in the day (when I was a young man), the recommendation was to run the engine at 2000rpm for something like 20 minutes to "run-in" the lifters to the camshaft.

 

Is this crucial on the 4.0?

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The purpose of keeping the RPMs up for the first 10 minutes is to keep the oil pressure up. You want to be certain the lifter/lobe interface has plenty of oil when the parts first get introduced to one another.

 

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1 hour ago, Eagle said:

The purpose of keeping the RPMs up for the first 10 minutes is to keep the oil pressure up. You want to be certain the lifter/lobe interface has plenty of oil when the parts first get introduced to one another.

 

Gotcha.  Makes sense.  Got the new lifters installed after coating them with Redline assembly lube.  Hopefully neighbor can help me lift head back on to block tomorrow.  Then time to install new head bolts and torque them to the God-awful level spec’d in the shop manual!

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On 5/2/2021 at 6:15 PM, AZJeff said:

Gotcha.  Makes sense.  Got the new lifters installed after coating them with Redline assembly lube.  Hopefully neighbor can help me lift head back on to block tomorrow.  Then time to install new head bolts and torque them to the God-awful level spec’d in the shop manual!

 

Unless something has changed, there's one head bolt that has to be painted with sealant of some type because it penetrates into a coolant passage. I'd have to look it up to know which one -- I assume you have FSM around?

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Yeah, guys, I am up to speed on the torque pattern and the one lower-than-the-rest torque value.  I also have the thread sealer needed.  The FSM is useful here, for sure.
 

All the head bolts are torqued per procedure, and all the valve train is in, slathered with plenty of “Redline” assembly lube.  Tomorrow the valve cover, new spark plugs, and the coil rail go on.

 

if the neighbor is available, I will enlist him to help me install the lower manifold bolts, since it’s impossible to see/feel them from above.  Then install fuel rail/injectors, and P/S pump & belt, fill with fluids.

 

Standby....

 

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