Engine Rebuild advice

[monteray7]

Here is my original post:

http://www.jeepkj.com/forum/f196/need-advice-what-do-i-do-62440/

So after talking to a mechanic, it would seem a valve stuck, a rocker arm fell off, and a piston may have been destroyed in the process and potentially some other fun internal problems that caused the engine to seize. They couldn't even start it manually. Tonight when I get off work I am going to start working on it. We had it towed home and I have cleared a spot in the garage right in front off the work bench. I have never rebuilt and engine before. Any advice before I get started? I plan on checking to see if it it even fixable before starting (i.e. checking bore hole thickness). Any and all advice is greatly appreciated. I don't have the money for a re-manufactured or used engine at the moment so it is worth it to me to try and rebuild it.

 

[Conundrum2006]

Not sure what to say. It is possible to rebuild, used would be faster to swap. Depends on how much damage was done to the engine, you will need a machine shop for the head. Possibly the block.

You might get away with replacing just the piston and repairing the head, problem is usually the quick fixes fail in a short time. I know quite a few who fixed the bare minimum and it didn't last.

If you rebuild it right I'm not sure how much time and money is involved.


Sent from my iPhone using Tapatalk Pro

 

[dougmac]

Does the engine turn over so you can remove the torque converter bolts? Take the intake off to get better access to the transmission to engine bolts.

Which head do you need? I have one for you. I have to check which side it's off.

Here is my adventure: http://www.jeepkj.com/forum/f196/sludge-death-57906/

 

[tjkj2002]

Here is my original post:

http://www.jeepkj.com/forum/f196/need-advice-what-do-i-do-62440/

So after talking to a mechanic, it would seem a valve stuck, a rocker arm fell off, and a piston may have been destroyed in the process and potentially some other fun internal problems that caused the engine to seize. They couldn't even start it manually. Tonight when I get off work I am going to start working on it. We had it towed home and I have cleared a spot in the garage right in front off the work bench. I have never rebuilt and engine before. Any advice before I get started? I plan on checking to see if it it even fixable before starting (i.e. checking bore hole thickness). Any and all advice is greatly appreciated. I don't have the money for a re-manufactured or used engine at the moment so it is worth it to me to try and rebuild it.

Best advice is to buy a remaned engine and swap in.

Doing this yourself without having done it before will be a very long job,sorry to say.Plus if your machine shops in your area are anything like what I have seen expect 3-6 weeks before they will ever even touch your stuff and have a 50% chance that it will be messed up anyways creating more work,more down time,and much more $$$ wasted.

I've seen others do this same very thing and 1-2 years later still have the engine in pieces on a table with no clue how to put it back together or what they even have or do not have.

 

[tommudd]

Totally agree with Troy above, buy a remanned and be done, you may think its cheaper to rebuild it yourself but this is not something to learn how to off fakebook or YouTube.
I've bought 7 pickups, Jeeps over the years where the owner started rebuilding the engine and gave up months later thinking someone could make sense out of his scrambled box of parts.
Always just bought an engine, in two day's it was running / cleaned up and in the front yard ready to sell. ( for a profit of course)

 

[JasonJ]

I'm on board with Tom, Troy, and any other person whose name starts with "T", apparently....

Not the time to LEARN how to rebuild an engine. It's not cost effective to do so. Maybe if you were dealing with a 1984 Chevy Caprice with a 305... Not an early 2000s Chrysler multi-valve v6 with a timing chain that Ghost Rider could use.

Buy a remanufactured long block, or a known-good salvaged engine from a wrecked KJ.

You say you don't have the budget for a used or reman'd engine... have you actually for real price checked the cost of a rebuild vs a junk yard motor? I just did a 30 second google check and found 4 master rebuild kits for a 3.7l KJ, all except one were roughly $800.

PLUS, you need tools that you dont and won't have on hand; so you'll need to buy, borrow, or rent those. A couple hundred more dollars. Heck, even the cheap engine hoist I got from Harbor Freight (it's awesome for what it is, btw) was $140 (15 years ago!).

THEN you have to figure in all of the machine shop work... assuming you can salvage your block and heads and don't need to buy a reman'd head, or heads, or go get used heads and then strip them down, have them checked, cleaned, measured and re-surfaced and valve seats worked up. You'll want to have the block hot tanked as well; you're looking at another $400-$1000 in machine shop work, and like Tom said, these guys don't work fast.. their schedules are weeks out at a time. ALSO I hope that stuck valve did not damage the camshaft journal it was riding on, because then you need a new camshaft; $160 for the left, $300 for the right from http://www.factorychryslerparts.com/showAssembly.aspx?ukey_assembly=587279&ukey_make=1064&ukey_model=15531

And THEN you have to consider all the time you have into it, and pray that you don't do anything wrong at all and damage anything. Like put the camshafts in wrong, or mis-align the timing marks and smash your new valves against your new pistons.

Oh, and there are other things you'll want to buy replacements for as you're doing the rebuild. Any sensors that look iffy, screws, bolts or fasteners you break or look corroded or sketchy..

Top that off with you have only a basic idea of what you're doing... aint good my friend. You'd be better off spending $500 now on a cheap motorcycle to get around in, and then saving your cash up to just get an engine pulled from a running vehicle. Drop it in in a weekend with a buddy's assistance and be DONE with it after checking it over and changing all fluids.

Some of us have been where you are now... I'd think this over very closely. If you add up my most conservative numbers from this post, which I didn't just pull all of them out of my ****, you can quite literally buy a used KJ, whole, running, insurable and registered, for the same cash. Use that donor vehicle for its engine and sell remaining for parts.

 

[GunnerSchenck]

Pretty much my exact thought have been stated above.
With those problems it's undoubtedly going to cost you more money to rebuild it than to find a salvageable motor. Rebuilds are pricey but worth it if you have the dough.
But, if you want the cheapest method, get a salvageable motor out of a rusted one if you have to.
Rebuilding your engine.. IMHO, not a good idea. Plus being that you've posted a few threads about your motor already, I'd imagine you're annoyed. So, how mad are you gunna be when you rebuild it and it won't start or kicks the bucket a second time?

Get a different motor. You're more likely to have access to the needed tools to swap a motor than you are to have the tools to rebuild one.
Google education is not always the best route.

 

[mrlavalamp]

+1 on buying a remanned engine, or one from a known runner at a salvage yard.

The price tag up front is larger than the rebuild kits, but you will have less downtime, and a better chance of success.

This gives you the opportunity to keep the engine you removed and either take it apart for the experience of it, or take it a step further and rebuild it slowly and meticulously. Then once you are ready, swap it back in and keep your 2nd motor on standby in case something happens.

If you want to learn to rebuild engines, I don't think there is any cheap and easy way to learn, you either pay for an education in the subject, or you pay through trial and error/discovery. Having someone of experience around to help is ideal, but I realize that not everyone has the luxury of knowledgeable and willing family/friends nearby.

Like most things in life, this old adage applies very well here: "You can have it cheap, fast or good. Pick any two". Just be aware of which 2 you have chosen.

 

[rjkj2005]

$1400 for a low milage used engine. Or $1500 for parts and machine work to rebuild same engine. It's not just pull it apart and replace parts. Sure you could do that and then be back doing it again in 6 month to a year if not sooner. To rebuild an engine right so it lasts requires block, crank, and head work.
I'd find a low milage engine and slap it in.

Sent from my XT1585 using Tapatalk

 

[tjkj2002]

Just think....................

I'm a 21 year ASE Master tech and have the knowledge,skill,and tools to rebuild almost any engine.

When my 3.7 dropped a valve(valve keeper failed) I bought a remaned engine,cheaper and quicker plus a warranty is nice also.

 

[Conundrum2006]

Another trick is if the junk yard list the vin, and they should although it's optional if they do. I used myCARFAX app to look the vin up and peek at the recorded service history. Did that for buying the engine off a low mileage liberty and later to double check the milage for the spare transmission I picked up.

I've rebuilt motors, started out doing things like cylinder heads and moved up. Even in the best circumstances it can take months to get it all back together and be ready to turn the key. When I know a engine job is a possibility I either find a good name rebuilt, low milage used or a decent used to rebuild if I have time on my side.
It is so much easier to swap the engine over rebuild. I don't want to discourage the OP too much, if the body is good I'd keep putting it back together but I'm stubborn that way.


Sent from my iPhone using Tapatalk Pro

 

[rigid]

Agree with all of the above . Have built many small block engines over the years for race cars and daily drivers . Have tools and equipment for an engine change like this but would not try to rebuild my engine in your case . Can almost promise you the add on costs at the machine shop will be 30% plus more than what you are expecting . With a day or two of looking I bet you can find a decent used one that will do what you need . Good luck