tapping in DS valve cover

Hi all. Could use some advice. 93 XLT, 4.0, manual, 2wd.
When I first got this thing it was ticking bad on driver side valve cover. I removed said cover and found that a piece of metal had been wired to the first rocker arm from the front. Well, that kind of left me dumbfounded. So I took it to a local shop and asked what the hell.
He told me about how rangers were bad to wear out in that area and that someone had wired it in there to quiet in down. So I replaced all the rockers on that side, but I don't think I replaced the push-rods at that time because they looked in decent shape. Long story short, after putting it back together it still had a tick, but not as bad as before. So I lived with it.
I ended up having some medical problems and parked it for a couple years. So there is only 200 or 300 miles on the new rockers.
It was bugging me so I tore into it again and I can see that the valve stem has been wore down. I had read (on this forum) that putting in a longer push-rod would be the best and easiest way of getting it quiet and wanted to get some opinions on the subject.
Basically looking for a part number. Autozone only shows one push-rod for my model

Tapping as you describe on a 4.0l OHV is most likely a collapsed lifter.
Could be a failing cam lobe but lets think positive, lol.

Remove valve cover and twist and try lifting and pushing down on push rods
If valve is closed you should barely be able to twist push rod with fingers, and 0 movement up or down
If valve is open then push rod won't move at all.
Rotate engine and keep testing for movement until you have tested all push rods.

If you remove rocker arm assembly and then put a straight edge across valve stems you can see if one is worn down.

If no worn valve stems or rockers, then you have a collapsed lifter.

Thanks RonD, I'll check out things as soon as daylight hits. I didn't add this little bit of information, but here it is. It only taps maybe 3 or 4 seconds at idle, then it's quiet for an equal amount of time, and it repeats that cycle over and over again. I can give it a little gas and hear the same thing, but it's hard to hear going down the road unless you get in a spot that echos back to the ear. And that's the part that is weird to me and has me confused, the equal tapping-not tapping, not the echo.(lol)

I had already pulled the rocker arm assembly for inspection. So I will try twisting/turning the push-rods on reassembly. I did check push-rod length and three are shorter than the others with the tapping one being the worst. I will be replacing at least 3 if not all. I also used a straightedge on top of valve stems and found (counting from front to back) 1,3,4 to be shorter. I could slip a .006 feeler gauge in between the valve stem and straightedge. Looking for comments and opinions. Thanks.

The 0.006 shouldn't matter on valve stems, and on the shorter push rods you should also notice the rocker sockets are also worn, this was fairly common on the 4.0l.

But the lifters will be the real culprit.
And unfortunately they can't be changed without removing the heads.

Hydraulic lifters compensate for normal valve train wear, and should last the life of the engine, but in the case of the 4.0l OHV this wasn't always the case.

My 4.0l has over 300k and valve train is still not "ticky" so knock on wood.

Hydraulic lifters have a one way valve(check valve or ball) inside that allows oil to flow in from oil pressure in the engine, but it can't flow back out.
When cam pushes lifter up the resistance from the valve spring pushes the plunger in the lifter down, since the oil can't flow out the way it came in the compression of the oil overcomes the resistance of the valve spring and the valve is pushed open.
There is a small hole in the plunger that lines up with the hole running thru the push rod shaft, during compression of the lifter some oil is squirted out this hole and it travels up the push rod and squirts out a similar hole in the rockers push rod socket, this helps lube the rocker and push rod contact point and the rest of the valve train.

A hydraulic lifter is pre-loaded when you tighten down the valve assembly, so plunger is push down slightly, .02 to .06 is normal pre-load, which is why the valve stems .006 difference wouldn't matter.

A spring under the plunger holds plunger up when there is no oil pressure which prevents ticking on startup, i.e. before oil pressure reaches lifter passages.
There is also a spring that holds the check valve in place so lifter can build compression pressure.

If there is a problem with either you can get a collapsed lifter, the plunger can't hold push rod up against rocker with sufficient pressure so you get a ticking noise, this can come and go, and will often be worse at idle because oil pressure is lower.
But what also happens is that oil is not being pushed up the push rod in sufficient quantity to prevent wear on push rod and rocker, so tick can get worse as wear increases the gaps.

Installing longer push rod doesn't change anything and if lifter is only "ticky" once in awhile longer push rod could hold valve open too long when lifter is working correctly, causing a burnt valve issue.


A collapsed lifter will show itself when you try to spin the push rod with your fingers, it will spin fairly easy since the pre-load is gone there would be very little pressure pushing push rod up against rocker and valve spring

I'm hoping it isn't the lifter, but I'll know after I get some new push-rods installed. Speaking of push-rods, mine don't have holes in them at all. Is that a normal thing for a 93? And should I invest in ones that do have a passage through them?

4.0l OHV oils rockers via oil passages in the valve train assembly so uses solid push rods.
So stay with solid.


But lifters are the problem.

I hear you about the lifters. But since the tapping is in only one spot/location, would it be possible to just replace the one lifter. The reason I ask is that my book says that if replacing lifter(s), then replace camshaft also. But correct me if I'm wrong, don't the lifters in my engine run off the crankshaft, and if so, does that mean that I would also need to replace the crank and lifters together? Basically I'm asking if I can replace that one lifter without pulling the engine and replacing everything?
Sorry for all the questions.

oilbased said:

I hear you about the lifters. But since the tapping is in only one spot/location, would it be possible to just replace the one lifter. The reason I ask is that my book says that if replacing lifter(s), then replace camshaft also. But correct me if I'm wrong, don't the lifters in my engine run off the crankshaft, and if so, does that mean that I would also need to replace the crank and lifters together? Basically I'm asking if I can replace that one lifter without pulling the engine and replacing everything?
Sorry for all the questions.

Click to expand...

They most definitely run off the CAMshaft. If you replace a lifter or two, just be sure to use some cam break in oil on the roller/lobe and it should be fine. IIRC you can sneak a few lifters out with the heads on? but not all of them...I don't remember but I can check tonight when I put my new heads on the short block.

I'd really appreciate that PlumCrazy. As you can tell, I have never worked on this engine (or any other) past replacing external parts and replacing the rocker-arms on this one. So any help is a gift and appreciated.
I wouldn't even have let the tapping bother me but I may have to sell it in the future and think that the tapping would drop the price a bit.

fYI, there is no valve lifters that you can change without removing the heads on a 93 4.0. I have my engine apart at the moment and no lifters can be remover/replaced without removing the head first.

I also have pictures and questions. I'm just trying to remember how to post pics at the moment.

this is a pic of the right (passenger side) of the motor.http://www.therangerstation.com/forums/attachment.php?attachmentid=18936&stc=1&d=1439685639
This is a pic of the driver-side engine. http://www.therangerstation.com/forums/attachment.php?attachmentid=18937&stc=1&d=1439685639
This is the bad lifter. http://www.therangerstation.com/forums/attachment.php?attachmentid=18938&stc=1&d=1439685639
Close up of passenger-side motor.http://www.therangerstation.com/forums/attachment.php?attachmentid=18939&stc=1&d=1439685639
Close up of driver side motor. http://www.therangerstation.com/forums/attachment.php?attachmentid=18940&stc=1&d=1439685639
pic of upper intake. http://www.therangerstation.com/forums/attachment.php?attachmentid=18941&stc=1&d=1439685639
Pic of dirty cooling passages. http://www.therangerstation.com/forums/attachment.php?attachmentid=18942&stc=1&d=1439685639

Passenger side of motor is clean and of good color. Driver side of motor has carbon build up. Why?
Lifter is second from the front on driver side, and it is bad. I thought it was the first one on driver side but I was wrong. I just used a screwdriver as a listening device but I was close.
When I first bought this truck, I knew it had problems. But I couldn't resist the price. I did a radiator flush from autozone per instructions but the results were less than desirable. It over-heater a couple of times and I flushed it again with clean water but you can see the results. My question is " how can I clean the coolant side of the motor and get good results?
Thanks is advance for responses.

I find it interesting that no one can/will answer my questions. I'm waiting on parts at the moment, but will be putting things back together soon and need my questions answered before I do. Can anyone help me out?

oilbased said:

I find it interesting that no one can/will answer my questions. I'm waiting on parts at the moment, but will be putting things back together soon and need my questions answered before I do. Can anyone help me out?

Click to expand...

Maybe because no one is willing to guess.......