98 TJ engine swap: automatic to manual transmission

Jms76 said:
My biggest concern is having to drill anything on the block or heads. Especially any drilling on the crank. I’d rather buy a fully rebuilt engine than having to drill or modify engine mounting. Didn’t think I’d be going down this engine change path, but learning quite a bit in the process. Sounds like I should be good, other than a couple of minor items. I’ll provide an update once I get into it.
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I am about 99% sure you will not have to do either of those. They use the same engine mounts, mount plates, etc. if you can get some pics of
The XJ engine you could compare the accessory mounting bracket bolt holes to your own. The brackets themselves will look different but you can get your eyes on where the bolts are. It should all be the same.
 
The engine is still in the Cherokee. Is only going to pull it if I purchase. Is there any telltale signs that would stick out on the engine while it is mounted in the vehicle with all the accessories on it? Solved the 90 degree filter adapter, but not sure you could really tell on engine mounts or accessory mounting holes. Any other apparent telltale checks, or things that can be done to physically verify prior to pulling engine from vehicle?
 
Jms76 said:
The engine is still in the Cherokee. Is only going to pull it if I purchase. Is there any telltale signs that would stick out on the engine while it is mounted in the vehicle with all the accessories on it? Solved the 90 degree filter adapter, but not sure you could really tell on engine mounts or accessory mounting holes. Any other apparent telltale checks, or things that can be done to physically verify prior to pulling engine from vehicle?
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Well, the motor mount brackets are different per vehicle but they bolt up the same. All of the aftermarket engine mounting plates have the same 6-7 bolt holes and they all bolt up fine, if that’s any indication. I believe Cherokee used a different water pump but that is only because of the fan being offset since the XJ has two smaller fans (one clutch one electric) vs the TJ just having one large clutch fan.

agreed with skylines, I’d go for it. Literally if you go to buy an engine block on rock auto it has 96-98 XJ and TJ both as the fitment for any of those years.
 
Here is what the current engine sounds like, apologies in advance for dark video, sound decent.

This noise is present cold and hot, idle and at rpm, seems to fade a little on if you rev and let off, then resumes. Engine has good power and runs strong, no stumble, backfire, or smoke.

We’ve done and checked the following:
New exhaust gasket and manifold
New wires, plugs, and dist. cap and rotor
Added engine cleaner to oil, ran
Changed oil and filter. Oil was black, but no large metallic debris. Plug has no shavings either.
Checked all rocker arms, pushrods, and springs. Not loose, damaged, rotate freely, no excessive play

When we pulled the intake/exhaust manifold, actually pretty clean, mainly just carbon. No wet oil, or indication that one cylinder was not working properly.

Going to perform a few more checks like pulling injector wires, draining oil, attempting to extract any non-magnetic metal from the pan, and maybe a little borescope work.

Then, probably pull pan if nothing obvious.
Any other suggestions? Just trying to confirm before pulling the engine. Engine has 178k miles, one owner. Not abused.

The only odd thing about this Jeep is when we first got it, had check engine light on for misfire. We found the # 5 plug gap really small. Fixed and reset, never happened again. Maybe piston contacted it, not sure. Not sure if that can happen, don’t now how much clearance there is between plug and piston TDC. And It was able to jump that much either by rod bearing, or some piston wrist pin issue, maybe the engine would sound much worse or have failed already.
 

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I have the gauge to do so, what do you think it will indicate. Thought about doing so, but felt it probably wound not help all that much to detect the knock especially if it was a rod bearing or wrist pin.

Since it runs good, other than the knock, valve train was good, and intake exhaust ports while manifold was off, looked the same across all cylinders. - was thinking a compression test won’t do much for me.
 
I've seen a cracked ring land on a piston make noises though not THAT loud. Also, when I hydrolocked my motor, it bend a rod but was other wise fine except the noise. It's an easy test and I'm kinda reaching for ideas is the main reason though. You said no sparkles in the oil and a tight valve train, so trying to think in another direction.
 
Haven’t done compression test yet, but pulled injector wires one at a time with no change. Here is a better clip from today.
 

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That's loud as hell man. You said you pulled the valve cover and all the push rods were tight? Did you turn the motor over to put each lifter on the heal of the lobe to check? Almost sounds like one of the rockers is smacking the bottom of the valve cover though.

And I think I could perceive a difference when you pulled the injector plug. Not in the clacking noise, but the motor noticed and the idle changed.
 
SkylinesSuck said:
That's loud as hell man. You said you pulled the valve cover and all the push rods were tight? Did you turn the motor over to put each lifter on the heal of the lobe to check? Almost sounds like one of the rockers is smacking the bottom of the valve cover though.

And I think I could perceive a difference when you pulled the injector plug. Not in the clacking noise, but the motor noticed and the idle changed.
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No noticeable change when pulling injectors one at a time. Checked all the bolts on the valve train, none loose. All inspected all springs, none cracked or damaged. Rotated all pushrods, smooth and not bent. Ran without valve cover and all getting oil flow. No excessive play. Also, no performance issues, backfire, smoke, loss of power. When I had the manifold off, all ports were typical dry carbon. None were oil soaked, or really different from one another.
Know for certain the rockers are not banging valve cover, same noise without it on.


Wish it was that.
 
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You are tracking with what I was asking about making sure the lifters were on the heal of the cam lobe when checking for push rod slop, right?

If all that checks out and the oil is clean, that rules a lot out. Does it sound like it's coming from inside the motor or could it be something external i.e. the distributor?
 
The lifters don’t get any more quite once the engine has heated up or run for a bit. Distributor is tight, checked last week and changed the cap and rotor. Had the intake and exhaust manifold off last well and put it all back together. Noise never changed. Originally thought it was an exhaust leak.

I think the pushrods probably have a little wear and since the adjustment is hydraulic, no real ability to set the lash. They all have a little movement I’d say Its consistent with good lash, not too tight or too loose. Maybe a tad on the loose side, nothing too crazy.

That is what is leading me to just pull the pan off. Can’t find the obvious source, just think something now resides in the piston or crank interface.

Sounds like within the motor to me, more toward the rear of the engine versus up near #1.

The only other thing I was thinking about was timing chain slop, not for the noise, but for cam not working properly. However, if the cam was out a little with the crank, felt there would be performance issues with the engine.
 
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I wasn't worried about push rod wear. I'm thinking more lifter wear or collapsed lifter. Again, are you getting what I'm saying about making sure each individual lifter is on the base circle of the cam when you check it for slack? I do think pulling the pan is going to happen, but the compression check is much easier to do and would show you a cracked piston.
 
SkylinesSuck said:
I wasn't worried about push rod wear. I'm thinking more lifter wear or collapsed lifter. Again, are you getting what I'm saying about making sure each individual lifter is on the base circle of the cam when you check it for slack? I do think pulling the pan is going to happen, but the compression check is much easier to do and would show you a cracked piston.
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Base of circle meaning all valves closed and no tension - i.e. lowest point on cam lobe profile.

Think I’m following. If that is the case. I was not that precise. I rolled and checked, rolled and checked, etc. Didn’t go intentionally to this point on each set of valves or cylinder.

How much play would you think I’d see on a pushrod that had the collapsed lifter?
 
If you can see any daylight, it's way off. No vertical play. Sounds like you were already looking for that though and your know what you are doing. I'd do the compression test because easy then on to pulling the pan.
 
If you still have the valve cover off, start your jeep. Now using either you hand or the handle of a screw driver push down on the back side of each rocker arms, above the push rod. See if the noise quiets down. This will help you determine if it is indeed a valvetrain noise.
If you determine it is a valvetrain noise. Try removing and inspecting the rocker arm pivots to see if they are scored and worn.

Another thing these 4.0 are famous for is cracked/broken piston skirts. My wifes WJ had a busted skirt on #5. If you drop the pan for inspection, you'll may find a chunk laying in the pan.
 
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williambmac said:
If you still have the valve cover off, start your jeep. Now using either you hand or the handle of a screw driver push down on the back side of each rocker arms, above the push rod. See if the noise quiets down. This will help you determine if it is indeed a valvetrain noise.
If you determine it is a valvetrain noise. Try removing and inspecting the rocker arm pivots to see if they are scored and worn.

Another thing these 4.0 are famous for is cracked/broken piston skirts. My wifes WJ had a busted skirt on #5. If you drop the pan for inspection, you'll may find a chunk laying in the pan.
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I’ll give this a shot, in your opinion with the 170k miles, is there any chance of making this into a reliable engine? Meaning, all the stuff I’d do to this is just a band-aid until the engine fails? My goal is to make this into a reliable and nice vehicle my kids can drive. And can go down the highway without blowing up or needing a tow truck.

Given that perspective, would it just be best to order a new rebuilt engine, put new clutch in during install and move on?

More research I do, any fix in this would just be a patch until it fails or has another issue.

Whether I get a fully rebuilt or the used jasper engine, seems like a pretty straight forward install.
 
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