2002 Jeep Wrangler



April, 21, 2010 AT 3:39 PM

Engine Mechanical problem
2002 Jeep Wrangler 6 cyl Four Wheel Drive Automatic 95000 miles

I have a 2002 Jeep Wrangler with an inline 6 cylinder engine. It started to make a tapping noise from the lifters. It's really noisy when I first start it up and quiets down after 15 minutes or so. I have used the engine flush which seemed to help a little. I also tried a thicker motor oil and that seemed to help but these two options didn't fix the problem. I am thinking it's a sticking lifter. I removed each rocker arm and pushed down on the push rods and the lifters seemed to be strong as I couldn't budge them.
Should I try more engine flush, I've done this three times now, or install a higher volume oil pump? My last option would be replacing the lifters and the manual says I have to pull the head off to remove them. Is there no way to remove them with the head still on?


12 Answers



April, 22, 2010 AT 3:45 PM

Come on Jeep guy! See my profile!

Mr. Tappet or Hydraulic Lifter, works like a "Hydraulic Jack"when they are "full" they lock (won't budge) And push up on the Push Rod!

What makes this so Cool, Is they SELF ADJUST, taking out slop between the "Lifter" and the Push Rod, EVERY TIME they move up and down.

HOW THE %&*$# ? you say!

Turddog say, while wagging his tail frantically, trying to make a new Jeep Friend, UNDERSTAND!....

While your engine is running, and has OIL PRESSURE, the TAPPET moves in and out of an OIL GALLEY or Oil channel, AS IT MOVES UP AND DOWN....

The groove (with holes), Being "dipped" into Oil Pressure, On the Tappet, Momentarily releases the tappet to re-adjust----ONLY USING OIL PRESSURE TO RELEASE!

Does this make sense?

No wonder there is no phisical way to feel the Spring Action, as in a New Un-Oiled Lifter! (there is no "hydraulic" in a new one YET!)

Now let me tell you the best thing to do to FREE-UP an Old Tappet

Your old one may have Build-up or deposits in it, preventing Efficient Re-adjustment, to take up Slack

How ever many oil changes it may take (4 would let me know if there was an improvement)


Substitute 1 quart of oil for 1 quart of Marvel Mystery the label, can run in your fuel too!

This will, if its able to, free up lifters.

Turddog is smart...Turddog always explains stuff....Turddog does not give a quick textbook answers.....Turddog really tries to help, but only with somewhat of a LEGIT answer.....Turddog is just a member like you, NO PAY!

Turddog has answered many posts (see profile)

Turddog answers nearly all of the CJ 5 and CJ 7 questions in their forums. (investigating them and other answers of mine, might benefit you on problems you may encounter.

I learn stuff too, just searching around (my weakness is these newer cyber cars)

I get few replies to my SUPER ANSWERS

What about you?

Love, Turddog



April, 22, 2010 AT 4:20 PM

So these are totally hydraulic lifters and have no spring inside? Do these lifters ever collapse and have to be replaced? I have run MMO three times now and still have the same issue. Do you think running it more times wll really help? I really think they have a build up on them that is not letting them work properly. I want to get my hands on them and check, but don't want to have to pull the head to do so.



April, 22, 2010 AT 4:49 PM

They do have a spring in them, which pushes against the Oil pressure and the pushrod, for readjustment, when oil pressure is applied.

I've taken a few apart (Hard) they have several sleeves, and a (for no better discription) A " Dime" or small " holeless" washer inside, that raises and lowers (expelling excess oil, when in oil pressure) and seals the assembly after adjustment is automatically made (like closing the valve, on a hydraulic jack). Making the assembly solid, while pushing the pushrod.

Have you removed the valve cover and PUSHED on rocker arms, While Running----to see if its just one, several or all, Clattering?

What about running " Lucas Oil Stabilizer" at oil change, now that you used MMO several times?


Love, Turddog



April, 23, 2010 AT 12:10 PM

My Jeep has been running superb since I bought it. I only had one issue about a month after I bought it, the check engine light came on.
I was like, WTF, hooked it up and computer said check gas cap and sure enough it was not tight. LOL.
Then about six months ago I decided to switch to synthetic oil, yes you can ask what was I thinking.
That's when I started noticing the tapping or clattering. I guess the synthetic oil cleaned out the sludge because I dropped the oil pan, by the way you don't have to break motor mounts loose for clearance like the manual said I had to do, and it had a fair amount of sludge in it. I thought maybe it was clogging the oil pickup. I cleaned it all out, took the pump off and cleaned it also.
Changed back to conventional oil, now I'm running 10w30 and also using Wix filter. Seemed to help as the noise seemed to go away. Then one day I started the engine in the morning and there was that confouned tapping again. It does quiet down after a few minutes. That's when I decided to clean the engine with MMO.
I used it per the instructions on two seperate occasions with no luck.
That's when I decided to pull the valve cover and try and inspect the lifters the best I could, that's why I asked about pushing the push rod for down by hand, someone told me if you can then the lifter might be bad, I'm kinda lost in that area of knowledge.

The noise was and is coming from the last two cylinders, not an exhaust leak.
I found the procedure for pulling the rockers arms and did it one cylinder at a time, making sure to put everything exactly back the way I took them off. I removed the push rods and the front ones had a little build up on them. The last four had, what I would call, excessive build up on them.
I cleaned them all off and even went as far as pouring some MMO directly on top off each lifter hoping that would help.
I put it all together and put in the rest of the MMO and filled it with 10w30. I started it up and " voila" no noise. I patted myself on the back and said good job.

The next day I get ready to go to work and start it up and, what do you know, there's that infernal tapping again. I am assuming that there's sludge and its clooging the lifter and not letting it pump up properly. The thing is, that the last few days it comes and goes. Sometime it will tap and sometimes it won't. I am going to run some MMO through the engine this weekend and see what happens.



April, 23, 2010 AT 2:04 PM

OK, Now for some possible scolding/ learning!

Any time you remove any part of anything!, Always keep it seperate, which end was where, so that it can be reassembled, EXACTLY as it came apart!


This stuff is " worn in" or MATED to the surface it Meshed with. Understand?

Changing, means they are no longer mate with their mate, and must Wear in again, possibly CHANGING heights or distances or sealing surfaces, Not a good thing, maybe not a real drastic thing, JUST DON" T DO IT AGAIN!

Remove valve cover, when we are clattering, RUN engine, FINGER your rocker arms, (on the pushrod side) Push hard while running, make the clatter ease off, one pushrod at a time


Go to auto machine shop (Not AUTO STORE) We are looking for a guy that understands " thousandths" and operation, not the former McDonaldland window guy!

Ask him if they make a pushrod(s)----(All may be the same, intake and exaust may be different)----Ask him if you can GET/ RUN/USE a pushrod---A FEW THOUSANDTHS LONGER, AND REPLACE THE NOISY ONES

I do not see a problem myself, this should not affect lifter operation, unless you get too long

It would let your lifters " re-adjust" deeper in the tappet

Let me know what he says

Love, Turddog



April, 23, 2010 AT 9:00 PM

12PAUL12, just so you might understand the tappet thing better.

When I rebuild a 258, my new tappets are in, and still " springy", since oil is only on them, NOT IN THEM.

Rockers are put on, One at a time, as this next step occurs

I rotate engine until each lobe on the cam, is down (as if valve, is in the closed position)

I install a " test" pushrod, and use a " dial Indicator" to measure, up and down pushrod travel, from CLOSED VALVE to BOTTOM of the " Springy Tappet" I really push hard on the pushrod end, of the rocker

I want 100 thousanths of spring, to be gone, in the Dry Tappet, By using a longer or shorter push rod. Without bottoming out the center of the tappet.

This will spring back out, up to 100 thousandths, a little at a time, Every self-re-adjustment, the tappet makesas wear occurs on: cam

tappet bottom and center top

pushrod (both ends)

rocker arm ends and center

valve stem

The valve seating in, actually reverses this process, sorta giving back to my " preset" tappet center depth.

I check all rockers and select a pushrod (length), that will somewhat closely achieve this goal, and install them permanently.

Now, when I am done, what I have is 12 dry, compressed tappets, when engine builds oil pressure, they will fill up, they will remain compressed, and start their self-adjusting operation, upward, from my preset depth.

Every time they move up and down, acting like a hydraulic jack.

Springing back out (ever so slowly, over time) WHEN METAL WEAR occurs, as the valve train wears in, then they will slowly adjust back out, over many miles of driving---hopefully never using up the 100 thousandths!

This is the advantage of tappets over solid lifters (no manual adjusting!)

If you replace a tappet or pushrod, as long as its not too long or short, the 1st time it moves up may not be right on the money, the second time up, it will have been self-re-adjusted and be correct new height.

Make sense?

Self responseYou are incredible, Turddog! Where do you get all of this? Its as if you study manuals, talk to machinists, auto parts fellers and have a Knack for repairing stuff, you will/ have make/make some girl really lucky to have you around! I wish I were your neighbor, so that I might get my Jeep fixed by an Expert!

Love, Turddog



May, 2, 2010 AT 9:54 PM

Push rods were fine ( had them checked). Replaced lifters and no more noise, except the usual jeep noise.<br />

More pics to come...............



May, 2, 2010 AT 10:43 PM



May, 2, 2010 AT 10:49 PM

I do not know your "situation", I would not even attempt to take apart and clean the lifters! (fearing something would not be exactly right, after reassembly and start-up!). I always put new ones in, if I am that far into it!

If you are reusing, what kinda wear was on the bottoms?

I am guessing you did it, Just to see what was going on with 'em.

(EDIT: sorry got carried away with the pics, I didn't see that you were replacing the Tappets!)


Has my contributionhelped you at all?

I see the room you have in there, thats cool!

I figure, once you get all that "Cyber Crap" off---theres nothing left in your way.

Your engine compartment is red......CLEAN hood well. Go to a place that does Vinyl lettering...get this done professionally!

I spray-bombed my compartment, when the engine was out, and hand painted this on mine! (next step is Toyota, Chevy and Dodge logos, bites in/out of them, on magnetic backing, in the teeth!) I like Ford, will leave them out of this!

Keep me informed, you seem to be very concious and tedious with your work.

Love, Turddog



May, 3, 2010 AT 7:59 AM

I did replace the tappets. More pics to come on that.

Funny story.

I went to my local parts store to buy some new tappets.
They only had four in-stock and said they could get the rest the next day.
I talked to a friend (mechanic type) and he said he could get them and have them shipped to the parts store.
The next day I go to pick them up and proceed to the shop to install them.
I open the boxes and there are two different kinds in the boxes.
One was stamped HT-2011 and one was stamped JB-2011.
The boxes were all labeled JB-2011.
I find out that they both will work for my 4.0L engine.
I didn't want to take any chances as the JB-2011 outer sleeve was almost 1/16 of an inch taller and had different springs inside (I actually took both kinds apart to see).
I called them back and they were certain that they gave me all the same kind, so I went back and showed them that they were stamped with two different part numbers.
They called a few different stores and the next day I had twelve of the same kind, HT-2011's.

I took them to another mechanic to have them " pre-oiled" to prevent any excessive wear during the re-start.
I installed them and used plenty of assembly lube.

New gaskets, new tappets, new thermostat and thermostat housing (the old one had a hole eaten through where the heater core mount is.), New drive belt.

A pretty straight forward job for a novice like me.

For less than $250.00.

All-Data is pretty awesome and it even has pictures!

The only part that was somewhat hard was the intake and exhaust manifolds as they are three separate pieces but they all bolt on the head together with 15. 15, that's right 15 bolts!

I get everthing put back together and go to start 'er up.
I have my fingers crossed and my eyes shut.
I turn the keys and presto it fires right up and runs great.
Now it only makes the familiar Jeep noises I have grown to love.

Once again my Jeep is happy as am I.

Thanks Turddog for providing me the knowledge and understanding of how a tappet or hydraulic lifter actually works.
I did get your e-mails, you do have some pretty awesome stuff.

My Jeep is all stock from the factory. I plan on keeping it that way for now, except for maybe under the hood, those teeth give it bite!
I may buy a second one in the future to tinker around with.

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