Loud engine ticking from 03 Wrangler X 4.0

[JABCAT]

Thanks for all the replies & suggestions. To answer a couple questions:

1. It's my son's daily driver. We have a few other vehicles, but none that he is able to drive for insurance reasons (all 550 - 700 hp). So it needs to be a "weekend" or couple afternoon fix. He's had his license for 2 months. He needs to be able to get to work reliably, practice, friends, etc.

2. I'm home for Summer, but our time is pretty booked with travel and other obligations (gone all next week, back for a couple days, gone again, rinse & repeat for the next few months), so again, fix has to be relatively quick.

3. I'm not worried about a complete overhaul right now, just want to make sure he's good to go on #1 above. I would just buy a new engine and swap that with him, but we're building a covered parking pad for his Jeep (lots of storms & hail here) which is looking at about $8k between the concrete pad & the structure (have to meet HOA & Town guidelines for appearance & building materials). Add to that our upstairs a/c went out & the estimate is $25k for a new air conditioning system (see storms & hail) that, if insurance doesn't cover, will be out-of-pocket. If $400 keeps the Jeep running without any issues for a decent amount of time, win/win.

4. I could take it to a shop & have them diagnose & fix, but I don't like paying high labor rates for something I can do myself. Plus I use working on the vehicles as a time to teach him how to do it. We maintain & modify all our vehicles ourselves as much as possible. We've overhauled & refreshed the entire suspension already, brake system, installed heated seats, head lights, headers & cat-back exhaust, and a bunch of other things. I want him to be able to fix anything he needs to vehicle-wise now & in the future.

If I can just swap some pistons, rings & bearings then be good for another 50k miles, that's the route I need to take at the moment.

 

[aston4]

The hardest step would be installing the crank and bearings properly , the front axle would have to have the shocks disconnected and max droop. Then the body/engine would have to be blocked up pretty high off the ground making it real tough to lift the crank while on your back. A dingle ball hone job would be no problem .

I have researched this a lot. Seems that 95+% of the time, the crank mains are in perfect condition, and there is no reason to even take a cap off and look at the main bearings. Just swapping in new pistons and con bearings should push the engine out to it's previous usual life (3-400k miles before Chrysler wrecked everything with the thin piston redesign). I would leave everything else alone and in place, and not even hone the cylinders if the factory cross hatch looks OK. If there are scuffs, only then hone.

ETA: especially do NOT replace the lifters, that will trash the cam in short order. Also keep track of where everything came from, and put it back in the exact same place: lifters, pushrods, con rods, etc. Lots of people say where the lifter or pushrod or rocker arm came from doesn't matter. Do not listen to them, label it and put it back in the same place it came from.

 

[MikeE024]

Was not ticking this morning. Son drove 1 mi to school this morning & 1 mi home this afternoon. Heard it when he was pulling up the driveway. 156,620 mi.

My engine sounds like that sometimes on startup (been that way since I bought it 4 years ago). I simply shut it off immediately and then restart it. It usually goes away. If it still does it, I simply shut it off again and restart it.

I didn’t read the entire thread to know what other details you may have found, but of you don’t have further proof of engine wear, I would replace the oil and run some marvel mystery oil in there to see if it goes away.

Then consider tearing down the engine if that doesn’t do the trick.

 

[aston4]

My engine sounds like that sometimes on startup (been that way since I bought it 4 years ago). I simply shut it off immediately and then restart it. It usually goes away. If it still does it, I simply shut it off again and restart it.

I didn’t read the entire thread to know what other details you may have found, but of you don’t have further proof of engine wear, I would replace the oil and run some marvel mystery oil in there to see if it goes away.

Then consider tearing down the engine if that doesn’t do the trick.

I agree a total teardown is not called for yet, but just to pull the oil pan and look for a chunk of piston definitely is called for, as that is the most likely finding.

 

[JABCAT]

I agree a total teardown is not called for yet, but just to pull the oil pan and look for a chunk of piston definitely is called for, as that is the most likely finding.

We did replace the oil pan 1700 miles ago; however, it wasn't making any noises or burning any oil then. Will definitely pull it again to see if anything is in there.

 

[ColoJeep]

We did replace the oil pan 1700 miles ago; however, it wasn't making any noises or burning any oil then. Will definitely pull it again to see if anything is in there.

Maybe use a bore scope through the drain plug and have a look around.

 

[MikeE024]

We did replace the oil pan 1700 miles ago; however, it wasn't making any noises or burning any oil then. Will definitely pull it again to see if anything is in there.

FYI, the only reason I don’t run MMO for my lifters right now is because the issue doesn’t happen as often with Redline 5w30 (that you don’t need).

Our issues might not have the same solution, but MMO is known to have fixed lifter problems (doesn’t always fix it right away).

Also, my knock issues happened more in the winter and when I ran 10w30.

 

[MikeE024]

Maybe use a bore scope through the drain plug and have a look around.

Solid advice imo…I wouldn’t drop the pan if I don’t need to.

 

[JKP]

FYI, the only reason I don’t run MMO for my lifters right now is because the issue doesn’t happen as often with Redline 5w30 (that you don’t need).

Our issues might not have the same solution, but MMO is known to have fixed lifter problems (doesn’t always fix it right away).

Also, my knock issues happened more in the winter and when I ran 10w30.

Run a HM oil or Valvoline R&P and it will clean up your lifter(s).

My YJ would do this in the winter until I ran HM through it. Running 0w-40 in it now, never came back.

 

[MikeE024]

Run a HM oil or Valvoline R&P and it will clean up your lifter(s).

My YJ would do this in the winter until I ran HM through it. Running 0w-40 in it now, never came back.

Valvoline/Mobil HM didn’t help the start-up tick, but I haven’t tried Valvoline R&P.

MMO in my 5w30 oil did help, but I went to Redline after installing the turbo (for the better NOACK numbers). I can only guess that the better pour point may have reduced the tick.

I’ve considered running a combination of Redline weights and add some MMO to see if the tick can further go away. I’ll look into this more. TY

 

[DuckNut]

. In one video he showed how lack of oil pressure would cause the noise to get louder & proper oil pressure would make it go away.

You missed how the ticking sound is different. Lifter tick is a different tone than a cracked piston. He also showed how using thin oil and a full crankcase of Lucas did not change the sound of the tick, because it is not the lifters. Changed to new lifters, same noise. When he was all done he reassembled with new pistons and the old lifters and it purred.

You may be skeptical of him selling piston kits, but he refuses to have sponsored videos hawking various items telling you how great they are. I enjoy his videos. I like seeing this type of stuff because he is learning everything there is to know and is not a parts changer and when he does change parts they are usually from his junkyard.

 

[aston4]

You missed how the ticking sound is different. Lifter tick is a different tone than a cracked piston. He also showed how using thin oil and a full crankcase of Lucas did not change the sound of the tick, because it is not the lifters. Changed to new lifters, same noise. When he was all done he reassembled with new pistons and the old lifters and it purred.

You may be skeptical of him selling piston kits, but he refuses to have sponsored videos hawking various items telling you how great they are. I enjoy his videos. I like seeing this type of stuff because he is learning everything there is to know and is not a parts changer and when he does change parts they are usually from his junkyard.

Lifter tick is super rare on the 4.0, it's almost never the issue. And you are right, lifter tick is an actual "tick." Higher pitched. Maybe young people don't know what a "tick" is supposed to sound like, because they've never heard mechanical clocks.

In the video here, the tick is the higher pitched pulse. The lower pitched pulse is called the "tock." Lifters tick. Pistons tock (knock).

Interestingly, this video sounds exactly like an engine with both a bottom end noise, and a top engine noise. Notice the tick is half the speed of the tock, just like lifter valvetrain noise is half the speed of bottom end noise, due to the 2:1 reduction by the camshaft gear.

 

[Bammo68]

Solid advice imo…I wouldn’t drop the pan if I don’t need to.

Mike is right, but I'd go so far as to say I wouldn't do *anything* unless you really need to with this Jeep. If money is tight and the vehicle is actually running reliably apart from the noise then in my view the best thing you can do is just treat it to fresh oil and keep a close eye on it. I mean, the worst that's going to happen here is that a piston lets go or a bearing seizes and the car is stranded. OK - not ideal but unless your son is planning on doing Moab so what? If that happens then do a full engine rebuild - even in the *very* unlikely event that the block was damaged by waiting you can pick up a replacement block for next to nothing. I think we are programmed to think that if we let it continue it will destroy itself and that's not likely here - and even if it were the implications of that aren't particularly bad. Its not like this is a collectable and rare engine!

If you want to spend some time with your boy and learn, then I would look for a tired used block from the same year and over a period of time rebuild it as a project. Do a little each weekend and don't rush. Its a ton of fun and chances are you can get a good used engine pretty darned cheap - maybe even a freebie if you ask around. Any specialist tools you need you can probably borrow for the short time you need them and the rest of us who are bored and stuck inside during this miserable winter (Southern Hemisphere) will happily offer advice!

Rebuilding a motor with the old man then swapping it in one weekend - that's a core memory right there...

 

[JABCAT]

You missed how the ticking sound is different. Lifter tick is a different tone than a cracked piston. He also showed how using thin oil and a full crankcase of Lucas did not change the sound of the tick, because it is not the lifters. Changed to new lifters, same noise. When he was all done he reassembled with new pistons and the old lifters and it purred.

You may be skeptical of him selling piston kits, but he refuses to have sponsored videos hawking various items telling you how great they are. I enjoy his videos. I like seeing this type of stuff because he is learning everything there is to know and is not a parts changer and when he does change parts they are usually from his junkyard.

I didn't miss that, I was just correlating the ticking in my son's Jeep with the low oil pressure. Which made sense when we drained his oil and only 2 qts came out. He hasn't heard the very loud tick/slapping since the new oil was put in.

Now I've moved on to trying to find the cause of his engine burning 4 qts of oil in 1700 mi. It hasn't burned any oil in the 2 years we've owned it. If it is pistons - & the initial noise I posted about sounds like it from the videos, then those will be replaced next.

Re: selling pistons & diagnosing piston issues, I work in research so I'm always examining potential bias. I've watched a couple more of his videos, and they all appear legit.

 

[JABCAT]

Mike is right, but I'd go so far as to say I wouldn't do *anything* unless you really need to with this Jeep. If money is tight and the vehicle is actually running reliably apart from the noise then in my view the best thing you can do is just treat it to fresh oil and keep a close eye on it. I mean, the worst that's going to happen here is that a piston lets go or a bearing seizes and the car is stranded. OK - not ideal but unless your son is planning on doing Moab so what? If that happens then do a full engine rebuild - even in the *very* unlikely event that the block was damaged by waiting you can pick up a replacement block for next to nothing. I think we are programmed to think that if we let it continue it will destroy itself and that's not likely here - and even if it were the implications of that aren't particularly bad. Its not like this is a collectable and rare engine!

If you want to spend some time with your boy and learn, then I would look for a tired used block from the same year and over a period of time rebuild it as a project. Do a little each weekend and don't rush. Its a ton of fun and chances are you can get a good used engine pretty darned cheap - maybe even a freebie if you ask around. Any specialist tools you need you can probably borrow for the short time you need them and the rest of us who are bored and stuck inside during this miserable winter (Southern Hemisphere) will happily offer advice!

Rebuilding a motor with the old man then swapping it in one weekend - that's a core memory right there...

While this scenario would be great, our issue is time. We all have very busy schedules, travel a lot, etc. For 8-9 months out of the year, I'm only home on the weekends, and those weekends are stacked with obligations. There are plenty if times when both my wife & I are traveling separately & he needs to get to work, practice, school...

Even now, the soonest I can get to looking at this more in-depth is maybe end of June. That's why I'm trying to gather as much info as possible so when I have time, we can just get after it & get it done.

 

[Bammo68]

While this scenario would be great, our issue is time. We all have very busy schedules, travel a lot, etc. For 8-9 months out of the year, I'm only home on the weekends, and those weekends are stacked with obligations. There are plenty if times when both my wife & I are traveling separately & he needs to get to work, practice, school...

Even now, the soonest I can get to looking at this more in-depth is maybe end of June. That's why I'm trying to gather as much info as possible so when I have time, we can just get after it & get it done.

Fair enough - sounds like you just need to fix it. In that case, the first thing to do is to identify what the actual problem is. A bore scope is quickest but may not be all that easy to actually diagnose it. Removing the pan will let you take a closer look but getting the pan out can be a bit of a juggle - you need to so some jacking up to clearance it. No matter what you do, if you have a limited amount of time and limited experience with the 4.0 then you can be sure that the "15 minutes" to pop the oil pan off will become 2 days because some tiny thing holds you up, a stud nut that won't loosen or is blocked by something.

Start with low expectations and just focus on taking a look inside for the first step. Order a new pan gasket so you can replace that regardless. Drop the oil, get a bunch of rags and a good torch and once you have the pan off be prepared to get dirty whilst you get your son to rotate the motor as you look to see if any of the piston skirts are cracked. Its messy and dark and cramped in there so don't expect to see the problem instantly. If you do see the problem, great —-> Step 2. If you don't see the problem - its probably because you can't see it not because its not there!

Step 2
Take the head off - means disconnecting the inlet manifold and wiring harness and then removing the head itself. Will take a few hours to do it the first time but its not especially hard to do. Inspect the head and gasket carefully for leaks, cracks and anything oddball with the valves - bent pushrods etc. Tops of the cylinders may tell you if there is a serious oiling issue. Wiggle the cylinders around and that will give you an idea of whether there is an issue with a piston skirt. By this point you should start to know if you have an issue. Heck - it might be bleeding obvious with a cracked piston, who knows.

Step 3 is to remove the rod bearings in frame, gently tap out the pistons/rods and then get to inspecting, measuring and ordering.

 

[JABCAT]

Fair enough - sounds like you just need to fix it. In that case, the first thing to do is to identify what the actual problem is. A bore scope is quickest but may not be all that easy to actually diagnose it. Removing the pan will let you take a closer look but getting the pan out can be a bit of a juggle - you need to so some jacking up to clearance it. No matter what you do, if you have a limited amount of time and limited experience with the 4.0 then you can be sure that the "15 minutes" to pop the oil pan off will become 2 days because some tiny thing holds you up, a stud nut that won't loosen or is blocked by something.

Start with low expectations and just focus on taking a look inside for the first step. Order a new pan gasket so you can replace that regardless. Drop the oil, get a bunch of rags and a good torch and once you have the pan off be prepared to get dirty whilst you get your son to rotate the motor as you look to see if any of the piston skirts are cracked. Its messy and dark and cramped in there so don't expect to see the problem instantly. If you do see the problem, great —-> Step 2. If you don't see the problem - its probably because you can't see it not because its not there!

Step 2
Take the head off - means disconnecting the inlet manifold and wiring harness and then removing the head itself. Will take a few hours to do it the first time but its not especially hard to do. Inspect the head and gasket carefully for leaks, cracks and anything oddball with the valves - bent pushrods etc. Tops of the cylinders may tell you if there is a serious oiling issue. Wiggle the cylinders around and that will give you an idea of whether there is an issue with a piston skirt. By this point you should start to know if you have an issue. Heck - it might be bleeding obvious with a cracked piston, who knows.

Step 3 is to remove the rod bearings in frame, gently tap out the pistons/rods and then get to inspecting, measuring and ordering.

Thanks for these steps. We've already replaced the oil pan previous, so familiar with taking it off. Also have a spare Felpro gasket already sitting in the garage.

Disconnected all the wire harnesses, and removed the intake manifold last weekend when we replaced the cracked exhaust manifolds with headers. Familiar with that fun process as well. Also completely removed & reinstalled the exhaust from the front cats all the way back.

The only thing I haven't done yet is remove the head. But I've done it on other engines (LS V8s) in the past.

 

[MikeE024]

Thanks for these steps. We've already replaced the oil pan previous, so familiar with taking it off. Also have a spare Felpro gasket already sitting in the garage.

Disconnected all the wire harnesses, and removed the intake manifold last weekend when we replaced the cracked exhaust manifolds with headers. Familiar with that fun process as well. Also completely removed & reinstalled the exhaust from the front cats all the way back.

The only thing I haven't done yet is remove the head. But I've done it on other engines (LS V8s) in the past.

What will pulling the pan do that a good view with a scope can’t?

I sometimes have a tick when starting a cold engine, and there was no evidence of an issue when the pan was off twice for unrelated reasons.

 

[Bammo68]

What will pulling the pan do that a good view with a scope can’t?

I sometimes have a tick when starting a cold engine, and there was no evidence of an issue when the pan was off twice for unrelated reasons.

Good question. In theory, the scope will show what's going on, yes. In practice, the visibility is always limited with the scope and the ability to discern actual cracks versus lines in the piston skirt is challenging if you don't have experience in doing it. Its a great tool if you know what to look for, but for a DIY'er it can be frustrating when you are upside down under the car, trying to see into a dark hole and continually getting black oil smeared across the lens! For the top of pistons - brilliant. For the underside of pistons - not always the easiest solution.

The second unspoken part of your question is also really interesting. We (I) have been assuming here that the tick is caused by a cracked or broken piston skirt and that it will be visible. In reality, it may not be cracked in a way that is easily seen. You might have an internal crack that has distorted the piston or uneven wear that's causing mild piston slap that is leading to the tick. Different oils, different operating temperatures and the noise goes away. This is why I would be hesitant to do too much to the engine if its still running reliably but JABCAT has outlined why they need to fix it.

At the end of the day, the investigation first to determine the root cause is almost never wasted time when the potential fix is simple and a known weakness (cracked pistons) anyway but you have to be aware that you might be fixing a non-issue if that investigation is inconclusive.

When you watch YouTube videos they always find the smoking gun in the video and fix it perfectly but the real world rarely works so neatly!

 

[MikeE024]

Good question. In theory, the scope will show what's going on, yes. In practice, the visibility is always limited with the scope and the ability to discern actual cracks versus lines in the piston skirt is challenging if you don't have experience in doing it. Its a great tool if you know what to look for, but for a DIY'er it can be frustrating when you are upside down under the car, trying to see into a dark hole and continually getting black oil smeared across the lens! For the top of pistons - brilliant. For the underside of pistons - not always the easiest solution.

The second unspoken part of your question is also really interesting. We (I) have been assuming here that the tick is caused by a cracked or broken piston skirt and that it will be visible. In reality, it may not be cracked in a way that is easily seen. You might have an internal crack that has distorted the piston or uneven wear that's causing mild piston slap that is leading to the tick. Different oils, different operating temperatures and the noise goes away. This is why I would be hesitant to do too much to the engine if its still running reliably but JABCAT has outlined why they need to fix it.

At the end of the day, the investigation first to determine the root cause is almost never wasted time when the potential fix is simple and a known weakness (cracked pistons) anyway but you have to be aware that you might be fixing a non-issue if that investigation is inconclusive.

When you watch YouTube videos they always find the smoking gun in the video and fix it perfectly but the real world rarely works so neatly!

I know what you mean about internet videos not always telling the whole story.

And that’s why I’m not telling Jabcat that his issue is any specific item, but I’m happy to tell him about my experiences.

His symptoms could end up being one or more issues. I assume our goal is to help OP logically diagnose the problem without being wasteful with his money or time. And there’s bound to be guess work in that process.