Bought the Comanche! what do I do with a seized engine?

[sevenn07]

I just bought the Comanche (previously mentioned in Comanche Find post) for $125. Now before I said it was not running. Well come to find out after I paid for it, she tells me the engine is seized. I was quite upset because before I bought it I asked if it was burnt up or just not running. Well she said it just wasn't running but today after I paid for it she found out otherwise.

 

So my question to you is can I possibly unseize it. I am going to try no matter what. I can get more that 125 out of the metal on it at a scrap yard or part it out. But I really want to build this thing so tips and possible tricks? On the farm we use oil in the heads, (don't laugh this one really works) water!, and WD 40. I am up for any more good suggestions. I was also told about an acid bath but I would rather not pay to have that done.

 

Thank you and hopefully this will be the start to another great build thread!

 

P.S. I apologize for I think previously posting this in the wrong forum :doh: I believe this is the right place pete? I am new so please forgive me.

[JeepcoMJ]

it could be unseized, but if it seized, the damage is done.

 

don't scrap out the truck if it's in halfway decent shape. put another motor in...they're cheap anyways.

[dasbulliwagen]

:agree:

[Wildman]

Around here.........4.0 engines go for $250, with low (100K) mileage. If that's what you have, you didn't state.

 

By the time you mess with trying to un-seize it, and not knowing what you'll end up with, you could have the engine swapped :roll:

 

You don't have alot of $$$ into it now, so that's worth swapping out the engine, and what ever else is needed to get it in good running shape.

 

The correct way to un-seize it, is to pull the head, pour PB-blaster onto each piston, let sit, repeat a couple of time, then hit the piston with a block of wood and a mallet.

 

Once you pull the head, you'll also see what you have inside. There more of a chance a bearing is spun and seized.

 

Like I said, swapping is quicker that messing around.

 

If your going to use oil or water in the head to un-seize it, then you have a good chance of blowing the head........IE: Hydro-lock. These engines are not Farm tractor engines :roll:

[Eagle]

Another vote for just installing a used engine. She apparently didn't tell you WHY it is seized. If from standing, it could be rusted rings and that can be freed up -- but there's a good chance it'll always use oil. If it's seized because it overheated, there may be other damage you'd have to do a tear-down to assess and repair. It isn't worth the effort -- just get a known-good engine from a junk yard and swap it in.

[Red 1989 MJ]

Welcome to CC :cheers:

 

I will vote for an engine swap too, depending of your truck conditions.

[75sv1]

I'd at least pull the head and pan. See what damage has been done if any. Then I'd do the routine as described about and pour PB Rustbaster, transmission oil or something else. I'd look for over heated bearings, broked camshaft, broken piston, piston rings etc.

You might get lucky. As others have said, these motors aren't bringing a hole lot of late. That depends on the year needed and milage of course.

Tom

[sevenn07]

Thank yall so much for all the information so far. Yes it is a 4.0 I6. She didn't mean to lie to me. Just kinda made me mad that I had bought it first. An engine would cost more than that down here, not exactly sure how much though. I don't want to scrap the truck. It is not in great shape though. No rust just has been ran through a house! But I will pull the engine and try to free it. I mean what can it hurt right? I hope to get it running and I will take lots of pics and post them along the way. I am really excited to get this project started. Anyone know a good place to pick up some axles for this badboy? 4.10s or 4.35s preferably front and back. Thank you!

[75sv1]

I think your was a Renix. I did a search on Car-Part.com It looked like $350 for an engine. The HOs were about the same. You also might do a search for axles on it. 4:10 axles usually cost a bunch though.

Tom

[jimoshel]

I have freed up too many motors successfully to encourage swapping without trying to unfreeze one first. If you've got big bucks then go ahead and replace. If your tight on the bucks then try to salvage it. Just light surface rust is enough to keep the starter from spinning one but with a little help from a screw driver on the fly wheel teeth or a socket on the harmonic balancer nut it often can be loosened enough for the starter to do it. First pull all the plugs and look for rust. just one cylinder or several? get a light and look into the plug hole, see if you can see anything.If it's really rusted up forget it. If no or slight rust then try an salvage it. First fill the cylinders with something. I've used trans fluid, kerosene, diesel, rust penetrate, Marvel Mystery Oil and yes, even WD40. Let it soak at least over night. use a pry bar on the fly wheel and see if you can move it. Even half an inch. If you can then rock it. Sometimes I have freed up a motor in less than 10 minutes. Other times I have spent a week on one. Mostly just letting them sit an soak. I would guess I've saved maybe 4 out of 5 motors doing this. Also the motor could be busted. A broken piece is jammed into something. Only a inspection will reveal that. Good luck and welcome to the madness. Jim

[-600JeepMJ]

how many miles are on the engine? If you have the time and a little space you can rebuild the engine.

[Pete M]

car-part.com shows a 4.0 block near little rock for 150. I searched for just the block rather than the whole engine.

 

1989 Engine Block Jeep Cherokee 4.0L,STOCK NO. 001807034

$150 Arkansas Wholesale Auto Salvage USA-AR(North-Little Rock)

1-501-945-2886/ 888-945-9685

 

same place had a complete engine for 200

 

1989 Engine Jeep Cherokee 4.0L VIN L AT CORE ONLY,STOCK NO. 001807033

$200 Arkansas Wholesale Auto Salvage USA-AR(North-Little Rock) E-mail 1-501-945-2886/ 888-945-9685

[Automan2164]

I vote replace with known-good used. They are so plentiful, and reasonably cheap, it just ain't worth the effort to try to save one that could have existing damage that drove it into the ground.

 

And this is coming from the king of money misers. (on stuff like this)

Rob L.

[75sv1]

car-part.com shows a 4.0 block near little rock for 150. I searched for just the block rather than the whole engine.

 

1989 Engine Block Jeep Cherokee 4.0L,STOCK NO. 001807034

$150 Arkansas Wholesale Auto Salvage USA-AR(North-Little Rock)

1-501-945-2886/ 888-945-9685

 

same place had a complete engine for 200

 

1989 Engine Jeep Cherokee 4.0L VIN L AT CORE ONLY,STOCK NO. 001807033

$200 Arkansas Wholesale Auto Salvage USA-AR(North-Little Rock) E-mail 1-501-945-2886/ 888-945-9685

 

Is that just the block, or is it a 'Short block", ie pistons, crank etc. I wouldn't mess with just the block.

Tom

[87Warrior]

My guess is that a main is to blame, because I would bet the engine overheated and was low on oil. But hey, its just a guess.

 

If it sucked in water, check for bent rods. More than likely the crank is fine.

 

You can have my 4.0 HO for cheap if you haul it away. 190K on it, but ran smooth and used little oil. Located near Wakefield, KS.

[sevenn07]

Well since this is not a DD truck. I have all the time in the world I want to work on it. And because I would like to learn the ins and outs of the engine I think I will begin with trying to free it. I mean It's not gonna cost anything but time. And maybe a bit of PB blaster, oil or whatever I use.

 

Thank you for finding that engine block for me. I have never heard of that place. Now I can search for parts myself. This place has been so helpful already and I will have plenty more questions to come. If I can not get it running then I may have to hit something up for a used one. My biggest problem other than the engine is getting axles. And they need to match gears on top of that! Most of the front axles are kept by shops around here for there own personal use.

 

I really appreciate all the comments. This is going to be a great learning experience and I am glad to have such a great group of people backing me. I hope to start on the engine this week if I can ever get her to find the title. I am afraid to take it out of her yard without it. My luck she will report it stolen.

 

Are there any big tips to pulling the engine out. I will strip probably just about everything from the engine bay whether it needs it or not. I am gonna clean it all up in there. Just gotta watch for old wiring. I will pull the radiator and hopefully the front grill. I was told to leave the transmission attached. Do yall all agree? If it doesn't make much difference I would like to leave the tranny for now. But if not then if not.

 

PS Thank yall so much again! I will do this multiple times (the thanking part). Just a habit because I want yall to know how much your time helping me, someone you don't even know, is appreciated.

[JeepcoMJ]

alright, humour me here.

 

remove spark plugs

 

try looking in with flashlight. if you can easily see that it's garbage, replace.

 

if it looks OK,

 

spray the crap out of the cylinders (by spraying through the spark plug holes) with PB blaster. DO NOT use oil or water or anything but PB blaster.

 

do that several days in a row, leaving the plugs out.

 

then put the truck in neutral with the tires blocked, grab a 19mm socket, and try turning the crankshaft with a breaker bar on the harmonic balancer. this WILL overtighten your harmonic balancer, but it shouldn't break the bolt off. just work it several days spraying it with pb blaster and trying to move it via the breaker bar.

 

 

I've had success with this method. do this with the engine in the truck...it's easier with it mounted.

[JeepcoMJ]

oh, side note.

 

once it's unseized, turn it over with the plugs out for awhile. disconnect the fuel pump and crank it. this will remove any chance of hydrolocking it.

[sevenn07]

oh, side note.

 

once it's unseized, turn it over with the plugs out for awhile. disconnect the fuel pump and crank it. this will remove any chance of hydrolocking it.

Ok well I shall try that. Uhm how bout a definition of hydrolocking?

[JeepcoMJ]

oh, side note.

 

once it's unseized, turn it over with the plugs out for awhile. disconnect the fuel pump and crank it. this will remove any chance of hydrolocking it.

Ok well I shall try that. Uhm how bout a definition of hydrolocking?

 

 

fluid in cylinder compressed equals kaboom and breaking $#!&.

[sevenn07]

Ahh ok. I have heard of that happening. Never new what to call it though. Thank you!

 

Will it help the engine out by tearing it down, cleaning out the carbon build up, any possible trash of sorts (hopefully none), and putting it all back together? I want to paint the engine as well if it is good. I will hopefully paint the engine bay and eventually the whole truck if it turns out working.

 

Oh and just to let yall know about the story as told by the seller. Her brother was loosing his foot to diabetes so he was put into some sort of foot cast. Well he apparently got to feeling good and wanted to get a hair cut. Well he went to pull out, put it in gear, and got his foot stuck, and ran into the side of his house. Well after they got him out, the truck was started back, moved to where it sits now I believe, and has not moved in a few years. So this is all the background I have on the truck.

[Pete M]

I would do the above steps before even thinking of a tear down. plus, it's possible that the starter fried, or the battery or cables aren't supplying enough juice to turn the engine over.

[JeepcoMJ]

I agree with pete.

 

 

take the socket and breaker bar to the bolt on the harmonic balancer (big pully on the crankshaft on front of motor) and try and move it by hand with the plugs out.

 

starter or battery cables could be the only problem

 

 

 

next point....if you're going to clean an engine, you MUST do a complete 100% teardown and THEN clean it.

 

I've lived and learned that...end result, some broken down crap got in a rod bearing. if you don't tear it down completely, something will stay in there.

[sevenn07]

I did plan on tearing down everything. Do I need to pull the pistons off the rods and everything? And could doing all of this (saying that the engine is good) mess something up worse than just leaving it?

[JeepcoMJ]

I did plan on tearing down everything. Do I need to pull the pistons off the rods and everything? And could doing all of this (saying that the engine is good) mess something up worse than just leaving it?

 

eh. do what I said before you take it apart, then if you *need* to, take it apart.

 

but you want EVERYTHING completely apart and cleaned, and at that point you'd be nuts to put it back together without putting new bearings, rings, and seals in it.