Newish Owner - Engine Problem

[Ryan Danielson]

Hoping for some help...

I purchased a 2004 Wrangler Rubicon 4.0 about 3 months ago with 110,000 miles. About 2 weeks after owning it developed a tick/knock at first start of day but would go away when warm. I took it to a local shop and they said its normal for the 4.0 to be noisy in the morning but to check back in if it doesn't go away when warm. Fast forward a couple months and now I definitely have a knock or loud tick even when warm. Afraid I might need to replace the engine as I have been reading on these forums about cracked pistons and such. What is the best place to source a reman or does anyone know of a reputable shop in oregon. I don't trust anyone when it comes to my vehicles so hoping someone has some good experience. I don't have the time or expertise to rebuild it myself. Thanks for your help!

 

[Chris]

First off, welcome from Salem, Oregon!

4.0 engines aren't quiet engines by any means. Ticking noises often turn out to be lifter tick (which usually goes away after 20-30 seconds after startup) or a cracked exhaust manifold. The cracked exhaust manifolds are pretty common, and they can cause a ticking noise that is persistent and doesn't go away.

A louder knock noise is usually a bad rod bearing or worse. At 110k miles though, your 4.0 is barely broken in. These things will go for 600k or more with basic maintenance.

@David Kishpaugh owns Jeep West and is hands down one of the most knowledgable guys you'll EVER meet when it comes to Jeeps. Not only that, he's trustworthy, does amazing work, and could easily diagnose your issue. If you aren't mechanically inclined, I would suggest bringing it to him. He's in Estacada, but he goes out of his way to pick Jeeps up in other parts of the state, so if you contact him, you could definitely coordinate something with him where he'd come by with a trailer and pick your Jeep up for you to work on.

He's been active on the forums for well over a decade, and if you ask around with anyone here in Oregon who has been into Jeeps long enough, they'll know him by name. Just mention his name, or his license plate "MUDB8".

I will also add that for these engines to crack a piston or have a rod bearing go bad is not by any means common.

 

[Ryan Danielson]

Awesome! Thanks for the reply. I took it to a muffler shop as exhaust leak was one of my first suspicions and was hoping that was my issue. Turns out that is not the case. I will reach out to Jeep West and see if he has any ideas or if he can check the jeep out.

Thanks!

 

[Chris]

Awesome! Thanks for the reply. I took it to a muffler shop as exhaust leak was one of my first suspicions and was hoping that was my issue. Turns out that is not the case. I will reach out to Jeep West and see if he has any ideas or if he can check the jeep out.

Thanks!

That's a good plan! Like I said, those guys are the most knowledgeable Jeep people in Oregon. They'll take care of you and then some. Not to mention their rates are really reasonable.

 

[AndyG]

I’d be shocked if that engine has any serious issues...I’ve had 6, they just run and run. Likely a lifter .

 

[mcraasch]

I'm new to the jeep world and have a knock as well

 

[TimboSlice]

Not trying to scare anyone as the exhaust leak problem would have also been my first go to, but look into a broken piston skirt. There are many video online of the noises they do make. The only sure way of checking would be to remove the oil pan. Prolly a good idea to have a gasket on hand. The broken skirt will be laying in the oil pan.

https://wranglertjforum.com/threads/broken-piston-skirt-now-what.3009/

 

[mcraasch]

Not trying to scare anyone as the exhaust leak problem would have also been my first go to, but look into a broken piston skirt. There are many video online of the noises they do make. The only sure way of checking would be to remove the oil pan. Prolly a good idea to have a gasket on hand. The broken skirt will be laying in the oil pan.

https://wranglertjforum.com/threads/broken-piston-skirt-now-what.3009/

Then what?

 

[Imapepper]

Get yourself a mechanics stethoscope or use a length of tubing or hose and find out where the noise is coming from

 

[TimboSlice]

Then what?

First make sure the skirt is in the oil pan. If it is, then its up to you to decide. Replace the piston or replace the engine. Prolly replacing the engine will be the most budget friendly, unless you have plans for some wild stroker upgrade. Dont overlook the timing chain as well.

 

[Shatto]

First off, welcome from Salem, Oregon!

4.0 engines aren't quiet engines by any means. Ticking noises often turn out to be lifter tick (which usually goes away after 20-30 seconds after startup) or a cracked exhaust manifold. The cracked exhaust manifolds are pretty common, and they can cause a ticking noise that is persistent and doesn't go away.

A louder knock noise is usually a bad rod bearing or worse. At 110k miles though, your 4.0 is barely broken in. These things will go for 600k or more with basic maintenance.

@David Kishpaugh owns Jeep West and is hands down one of the most knowledgable guys you'll EVER meet when it comes to Jeeps. Not only that, he's trustworthy, does amazing work, and could easily diagnose your issue. If you aren't mechanically inclined, I would suggest bringing it to him. He's in Estacada, but he goes out of his way to pick Jeeps up in other parts of the state, so if you contact him, you could definitely coordinate something with him where he'd come by with a trailer and pick your Jeep up for you to work on.

He's been active on the forums for well over a decade, and if you ask around with anyone here in Oregon who has been into Jeeps long enough, they'll know him by name. Just mention his name, or his license plate "MUDB8".

I will also add that for these engines to crack a piston or have a rod bearing go bad is not by any means common.

DIAGNOSTICS is Critical.

Once upon a time, we automatically changed plugs, points, condenser, rotor and cap, but today Throwing Parts at a problem is not only expensive but pretty much stupid.

The newer the vehicle is, the less you need to do because the computer tells you what is wrong. They are no longer "idiot lights," they actually pass on important information.

Mechanics don't use a $25.00 'code reader' they use a $5,000 Snap-On diagnostic tool that tells them things that will astonish you. For example, Oxygen Sensors work until they are out of operating parameters and the computer adjusts and compensates for things like that and spark plug wear, etc. as well as adjusting for altitude and the Automotive Tech knows all that in seconds.

I didn't replace my Dakota's transmission because I nosed around enough to find the real problem and it lasted 623,000 miles. The story is here: https://www.allpar.com/cars/stories/shatto.php

 

[bromel]

Can you post a video? It'll be much easier to diagnose that way.

The 4.0 is notorious for lifter ticks and rattles and in most cases they can be ignored. Does the noise present itself immediately after startup, or does it take a little while to develop. A piston skirt is usually a pretty dramatic sound that sounds similar to rod knock, and it never goes away. Lifter noise is more guttural and usually disappears with higher RPMs. How does yours sound when you rev the engine? Was the noise more pronounced after an oil change?

Update: Just realized this thread is old. Never mind

 

[Kevin E]

Not trying to scare anyone as the exhaust leak problem would have also been my first go to, but look into a broken piston skirt. There are many video online of the noises they do make. The only sure way of checking would be to remove the oil pan. Prolly a good idea to have a gasket on hand. The broken skirt will be laying in the oil pan.

https://wranglertjforum.com/threads/broken-piston-skirt-now-what.3009/

Yep. I went through that experience with piston number 4. Rebuilt and good to go.

For the record, NO engine is bullet proof!!