Taddraughn's 1989 Comanche Progress Thread

[taddraughn]

Hi Guys, 

 

Picked this '89 Comanche Pioneer up about a week ago. Been sitting in the same spot in my neighborhood since I moved in 4 years ago. And as my new daily is an ND miata and my long term Lancia Fulvia project is coming to a close, it felt right to get something interesting with a little practicality to tinker on. 

 

 

Since it didn't run a friend helped me get it to the parking pad I have in my cul-de-sac. 

 

 

Quickly realized it didn't have spark or fuel. Spark was the ignition coil but I also threw a new cap and rotor at it for good measure. That solved the spark issue. 

 

Then I pulled the fuel pump... lol no wonder i didn't have fuel. 

 

 

So I yanked the whole tank and ordered some new stuff. This morning I rigged up a cheapo fuel pump inside a 1 gallon can to see what it would do and voila. Cranked right up. 

 

 

This allowed me to drive it into the garage where I can actually start to work on it. 

 

 

Looks nice next to the little Fulvia!

 

The engine sounds pretty bad though.. not sure if it's a stuck lifter or something worse. Here's a YT link if anyone wants to listen and tell me!

 

 

Maybe piston slap? maybe lifter? idk.. 

 

I drained the oil and will pull the pan to check things out. But headed on vacation in a couple days so it'll probably have to wait a few weeks. 

 

Bonus picture of the Fulvia project I'm finishing if anyone is interested.. I made a custom EFI system for this car over the last 4 years and it has been a long journey but finally close to done. Runs on a Haltech Nexus R3, has a cam sensor where the distributor was, so fully sequential injection and ignition with VR38 GTR coils, Pico injectors in some 3D printed aluminum runners, Carbon plenum I made, CWA400 water pump, etc etc.. Basically all custom but it was a really fun project. Wiring the car from scratch so that's a WIP but here's a pic as it currently is 

 

 

 

Looking forward to learning from you guys and getting this thing back on the road!

 

 

 

 

[89 MJ]

That looks like a very nice, honest, original MJ. Great find!

 

In terms of the ticking sound, it sounds like it could easily be either a lifter, piston slap, or an exhaust leak. I'd check for the exhaust leak first. The factory manifolds are known to crack and the intake and exhaust manifold bolts are prone to loosening up over time. 

 

That Lancia looks like a very cool project!

[taddraughn]

33 minutes ago, 89 MJ said:

That looks like a very nice, honest, original MJ. Great find!

 

In terms of the ticking sound, it sounds like it could easily be either a lifter, piston slap, or an exhaust leak. I'd check for the exhaust leak first. The factory manifolds are known to crack and the intake and exhaust manifold bolts are prone to loosening up over time. 

 

That Lancia looks like a very cool project!

 

It seems to be very original and just one little rust hole in the passenger floorboard that I missed in my initial check because it was behind the foam piece that comes down the firewall. Water either ran into that corner or was held there by the foam but shouldn't be a big deal to weld up just one little spot. Everywhere else was surprisingly solid so not much welding to do. 

 

I'll pull the manifolds and have a look at them. Would be great if it's an exhaust leak or lifter as that means I'll get to drive it a bit before an engine rebuild. But fine by me if I do need to rebuild the engine. Parts seem so cheap for these things but my basis is my last two project (Lancia and Audi parts are expensive  )

 

Thanks! The Lancia is a ton of fun and very happy to have it back on the road now. I restored it back in 2018. It was super rusty and required a lot of metal work. Back then I didn't mess with the engine other than having the head re-done. Eventually lost a cylinder and I told myself the new engine i built for it would not be carb'd. Took forever but very unique set up on a car that's already somewhat rare stateside. Registry a guy keeps has around 400 or so in the US so it always gets lots of attention because no one knows what it is lol. 

[Gojira94]

Welcome to the forum, great find!

 

Quick and easy thing to check is pull the valve cover and see if anything feels loose while rolling it over by hand, i.e. pushrod slack or a loose rocker. The 4.0 wasn't really known for piston cracking until the later years (96-04) but possible. Pulling the cover will also give you some insight as to how well it was kept on oil changes. If it looks a bit sludgy, an engine flush cycle with Liqui-Moly might free up some deposits if there's anything in the lifters gumming them up, as well as helping to free up the rings.

 

Click the link below to add your MJ's VIN number to the registry when you get a chance:

 

1989

 

[taddraughn]

3 hours ago, Gojira94 said:

Welcome to the forum, great find!

 

Quick and easy thing to check is pull the valve cover and see if anything feels loose while rolling it over by hand, i.e. pushrod slack or a loose rocker. The 4.0 wasn't really known for piston cracking until the later years (96-04) but possible. Pulling the cover will also give you some insight as to how well it was kept on oil changes. If it looks a bit sludgy, an engine flush cycle with Liqui-Moly might free up some deposits if there's anything in the lifters gumming them up, as well as helping to free up the rings.

 

Click the link below to add your MJ's VIN number to the registry when you get a chance:

 

1989

 

Thanks for the suggestions! I'll start with pulling the valve cover and taking a look and maybe try the liqui moly stuff and see if that frees things up. 

 

I posted in the 89 sub-forum yesterday to get mine added to the registry! Interested to see where it was originally sold

[taddraughn]

3 hours ago, Gojira94 said:

Welcome to the forum, great find!

 

Quick and easy thing to check is pull the valve cover and see if anything feels loose while rolling it over by hand, i.e. pushrod slack or a loose rocker. The 4.0 wasn't really known for piston cracking until the later years (96-04) but possible. Pulling the cover will also give you some insight as to how well it was kept on oil changes. If it looks a bit sludgy, an engine flush cycle with Liqui-Moly might free up some deposits if there's anything in the lifters gumming them up, as well as helping to free up the rings.

 

Click the link below to add your MJ's VIN number to the registry when you get a chance:

 

1989

 

Just saw underneath your post numbers it has your location listed as Clayton! I'm in south Garner and only around 12 minutes from downtown Clayton.

[taddraughn]

Couldn't resist tearing into it a little before heading out for my vacation... 

 

With the valve cover off it really doesn't look too bad. One thing i did notice is that the bolts came out really easy and some seemed quite loose.. 

 

 

Pulled off the intake and exhaust manifolds. Clearly some kind of leak was or is happening near the rear of the engine. 

 

 

 

and some of the worst welds I think I've maybe ever seen... Looks like someone snaked a mig torch in with everything assembled and just hoped for the best LOL

 

 

Also noticed this connector that wasn't hooked up to anything is severely melted.. Not sure what it is supposed to be for.

 

 

Have a feeling I'll be remediating quite a bit of wiring on this project :)

[89 MJ]

Well, with the soot on the intake and the boogers on the manifold, it looks like you might've found your ticking. Yikes.

[Eagle_SX4]

32 minutes ago, taddraughn said:

Also noticed this connector that wasn't hooked up to anything is severely melted.. Not sure what it is supposed to be for.

 

That looks to be the connector for the washer lever sensor. It was never used on the Comanche but was an option on the Cherokees. The Comanches are missing the interior wiring for the light. 

 

35 minutes ago, taddraughn said:

and some of the worst welds I think I've maybe ever seen

The exhaust manifolds are known to crack. Easiest solution is to grind out the old weld and weld it back up. You can also swap to the newer H.O. (91-95) header with the bellows built in which are less likely to crack. If you do that you will also need to replace the down pipe and figure out something for the egr. I did the swap and just cut the egr bung out of the old header and welded it in to the new header and cut and extended the egr tube...

 

Also looks like your valve cover was leaking a bit. Either the gasket or the oil fill cap both can cause leaks. My oil fill cap is leaking.

[taddraughn]

8 minutes ago, Eagle_SX4 said:

That looks to be the connector for the washer lever sensor. It was never used on the Comanche but was an option on the Cherokees. The Comanches are missing the interior wiring for the light. 

 

The exhaust manifolds are known to crack. Easiest solution is to grind out the old weld and weld it back up. You can also swap to the newer H.O. (91-95) header with the bellows built in which are less likely to crack. If you do that you will also need to replace the down pipe and figure out something for the egr. I did the swap and just cut the egr bung out of the old header and welded it in to the new header and cut and extended the egr tube...

 

Also looks like your valve cover was leaking a bit. Either the gasket or the oil fill cap both can cause leaks. My oil fill cap is leaking.

 

Oh interesting. I can understand using the same harness but just leaving a connector unsealed seems like a weird choice. Maybe it only melted due to proximity to exhaust if it wasn't used for anything. 

 

I'll probably swap to the new style header or get one of the banks ones. I can just weld in the EGR bung to keep that or maybe just delete the EGR altogether.

 

 

35 minutes ago, 89 MJ said:

Well, with the soot on the intake and the boogers on the manifold, it looks like you might've found your ticking. Yikes.

Yeah not knowing the history of the truck I'm not sure if the exhaust is still leaking or if the soot was before the welds the noise was something else? In any case I will replace the manifold and see if the noise persists. If it does I'll just yank the engine and go through it. 

[89 MJ]

16 minutes ago, taddraughn said:

 

Oh interesting. I can understand using the same harness but just leaving a connector unsealed seems like a weird choice. Maybe it only melted due to proximity to exhaust if it wasn't used for anything. 

 

I'll probably swap to the new style header or get one of the banks ones. I can just weld in the EGR bung to keep that or maybe just delete the EGR altogether.

 

 

Yeah not knowing the history of the truck I'm not sure if the exhaust is still leaking or if the soot was before the welds the noise was something else? In any case I will replace the manifold and see if the noise persists. If it does I'll just yank the engine and go through it. 

Just keep in mind that the O2 for Renix is in the manifold. Also, you will have to either clearance the Renix intake or the HO exhaust manifold because they will contact each other. Been there, done that.

[Eagle_SX4]

47 minutes ago, 89 MJ said:

Also, you will have to either clearance the Renix intake or the HO exhaust manifold because they will contact each other. Been there, done that.

I must have gotten lucky because I did not have to clearance anything to get it to fit. It bolted right up with no issues.

[89 MJ]

7 minutes ago, Eagle_SX4 said:

I must have gotten lucky because I did not have to clearance anything to get it to fit. It bolted right up with no issues.

Interesting. Mine was a stock 96 exhaust manifold and I had to clearance a couple of lower corners on my intake to get it to clear. I suppose it could've been a casting variance with the intakes or a manufacturing variance with the exhaust manifold flange. 

[taddraughn]

Thanks for the heads up! Good to know ahead of time it might need a little massaging to work. 

[89 MJ]

Yes, learn from my mistakes. Don't spend time and money with paint until you know that they fit

[Eagle_SX4]

32 minutes ago, 89 MJ said:

Mine was a stock 96 exhaust manifold

I used a cheap aftermarket one.

[89 MJ]

58 minutes ago, Eagle_SX4 said:

I used a cheap aftermarket one.

Maybe that's the difference. Mine was an OEM one. I'd guess Taddraughn would also use an aftermarket one, so if that's the case, he should be good to go. 

[Gojira94]

On 7/7/2025 at 7:03 PM, taddraughn said:

Just saw underneath your post numbers it has your location listed as Clayton! I'm in south Garner and only around 12 minutes from downtown Clayton.

 

Cleveland area? I'm in the Flowers area behind the Harris-Teeter. Small world. 

 

Glad you saved this one, making some progress!

[taddraughn]

On 7/10/2025 at 1:42 PM, Gojira94 said:

 

Cleveland area? I'm in the Flowers area behind the Harris-Teeter. Small world. 

 

Glad you saved this one, making some progress!

 

I'm just North of 42 off of Cornwallis, so not far at all! Looks like you've been doing excellent work on yours, I need to swing by sometime and see what they're supposed to look like! lol. 

 

Back from vacation and starting to peel back the layers on this thing. I'm not sure I will be able to resist the urge to tear it all the way down but we'll see lol. It's clear the work done previously was mostly hack jobs. 

 

Think I'll pull the pan today and maybe check how the bearings look/feel. The entire underside is so covered in oil. Not sure if the RMS is to blame or the VC but doesn't hurt to replace it and gives me a chance to check things out. Tempted just to pull the head off too with the POs description of the car being driven overheated at one point before it was parked and given how cheap they are. That will really give me a chance to check things out.

[taddraughn]

Okay so did manage to pull the pan today. Ended up just about disconnecting the front axle to get it to clear. Also used a little jack to move the axle down a bit more for clearance. 

 

 

Looks like someone halfheartedly cleaned the pan at some point. 

 

 

The bottom is super sludgy though

 

 

Hard to tell in this photo, but I noticed that the rods are stamped 1-6 on the rod and cap. do they come like that from factory or does that mean someone has been there before?

 

 

Got a look at the portions of the cylinder walls I could see and don't see any visible cross hatching, but do see some vertical scoring. I also pulled the plugs and see #6 was not firing at all; plug looked brand new. 

 

So I think at this point I'll just pull it for a rebuild. 

[89 MJ]

I don’t think they were labeled from the factory, but it’s been a while since I’ve had the pan off of a 4.0. I’d be doing a rebuild too if I were you. 

[taddraughn]

Back from vacation and ready to start tearing this thing apart some more. 

 

This afternoon I finished pulling the front axle out of the car. Things are coming apart pretty easily, thankfully. 

 

 

Tomorrow I'll probably go head and pull the transfer case and transmission out. A friend of mine is going to loan me his engine hoist and stand for the 3rd time lol. So hopefully next couple weeks I can start to get the engine bay cleaned up with everything out of the way and get the block and head over to the machine shop. Might just buy a new or re-man head for it but will wait and see what things look like when I take it apart.