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Unread 05-07-2012, 06:10 PM   #1
bmlarson12
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97 Jeep Grand Cherokee 5.2l rebuild help

My 1997 Jeep Grand Cherokee Laredo was making a knocking sound, which according to the mechanic is a bad main bearing. He also said that because of the metal coming from the bearings, it needs to be rebuilt.

Technically I am about to graduate from high school, and this is my dad's car at this point, so I have to first off convince him not to get rid of it. If I am able to rebuild it, I may be able to keep it. So how hard is it to rebuild a 5.2l? What special tools do you need to rebuild it? How long should it take?

I don't know if I can convince my dad to let me rebuild it, but if I prove I know how (and I have some idea) I may be able to.

Last off, if I do rebuild it are there any good mods for it? I want it to be just as fuel efficient as before, if not better. I also found rebuild kit at
http://www.rpmmachine.com/shop/index...t_detail&p=115
are they any good?


Last edited by bmlarson12; 05-07-2012 at 06:32 PM..
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Unread 05-07-2012, 06:31 PM   #2
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I also know it has been maintained because my dad bought it new... 15 years ago...
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Unread 05-07-2012, 08:31 PM   #3
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anything??
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Unread 05-07-2012, 11:16 PM   #4
ratmonkey
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Special tools:
calipers and micrometers and the ability to use them
Torque wrenches in ftlb up to 150ftlb and an inlb wrench to 150inlb.
Plastigage and the ability to use it.
Factory service manual or a builders manual for the dodge 5.2.
Engine stand
Engine hoist
COMPLETE set of hand tools, wrenches, sockets, pry bars, screw drivers,torx and Allen keys, etc...
Piston ring compressor.
Block machining service (always have it at least honed with a torque plate installed.)
Lifting devices, straps, chains, rtc. A load leveler for the engine hoist helps a lot.
A torch set comes in very handy dealing with exhaust.

Things to do while it's out.
Must do:
Hughes engines or aps aluminum plenum pan.
replace the flat spot in the y-pipe with a straight piece of pipe.(10ish horsepower free)
full tune up with new coil too
Replace heads with engine quest iron ram heads. The stock are cracked 100% of the time. Heads should either be machined and rebuilt it replaced in an overhaul, magnum heads are best replaced. The eq heads are only about 300/side anyways.
Oil pump, go high volume, they're cheap
Timing set
Should do.
New lifters, cam, pushrods, rockers
Distributor if any play in the shaft
Water pump

A rebuild can be done in a few days to a week from start to finish of actual wrench time. But, you need to have the block sent to a machine shop for bore inspection before ordering parts, as you may need the cylinders cleaned up at .005-.060", and that effects your ring and/or piston choice.
Have the shop install cam bearings and the freeze plugs for you, cam bearing install requires a special tool and a steady hand.
You'll need to inspect the crank for signs of wear and scoring. This determines your crank and rod bearing selection, but the plastigage us the final word on bearing size. You may go through a couple sets to find the right one
If the crank is scored, buy a new one.
After final assembly you WILL need to take it to a dealer to have the distributor synchronization set correctly. You can not do it at home.
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Unread 05-07-2012, 11:20 PM   #5
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You'll probably have 1750+ in parts and labor into it doing everything you can yourself. A remanufactured short block isn't much more, but doesn't address the heads or plenum pan, and those are major issues with this engine.
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Unread 05-08-2012, 12:10 AM   #6
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couldnt have said it better...may be easier to bu a reman to swap in if you dont have much experience wrenching...IMO a complete teardown and rebuild isnt something you want to take on as your first major project unless you have someone who has experience to guide you through it. although while you have it apart swap to 703 injectors and port the intake along with what rat monkey said.

@ratmonkey what do you mean by distributor synchronization, sorry never heard the term before
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Unread 05-08-2012, 01:46 AM   #7
ratmonkey
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Quote:
Originally Posted by RedneckZJ View Post
couldnt have said it better...may be easier to bu a reman to swap in if you dont have much experience wrenching...IMO a complete teardown and rebuild isnt something you want to take on as your first major project unless you have someone who has experience to guide you through it. although while you have it apart swap to 703 injectors and port the intake along with what rat monkey said.

@ratmonkey what do you mean by distributor synchronization, sorry never heard the term before
The camshaft sensor is responsible for injector pulse timing. The ONLY way to set that is with the Chrysler drbiii tool. spark timing is not set with the distributor and can not be adjusted that way.
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Unread 05-08-2012, 11:04 AM   #8
RedneckZJ
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ah ok never heard that
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You drive a tj, we drive a zj. We have more power while you get more shower. We get the v8 while you get there too late. You have 2 doors well, we have 2 more. Ours costs a grand while yours has a price we cant stand.
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Unread 05-08-2012, 01:47 PM   #9
bmlarson12
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I found out that I may be able to take it to my uncle's farm to rebuild it. He also builds race cars, so he is very experienced. I know the crankshaft will need work or replacement, but I think that part won't be too bad if the machine shop does crankshaft work. My uncle also has all of the tools needed to work on most engines, I am wandering about the distributor. How does that work?

Does anybody have suggestions for any relatively small upgrades?

I also saw there is an air intake manifold called "HUGHES / EDELBROCK FI AIRGAP KIT" that several people said gives you more power and tends to be more fuel efficient. I don't know if it is much better or not but it has no plenum gasket to go out. Would it be worth adding headers (or are there any headers that are not over $600)?
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Unread 05-08-2012, 07:35 PM   #10
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If you do a completely custom exhaust, there are still one or two sets of headers out there to use. Summit street rod center dump, like i have and hedman tight tubes. the summit runs about 250$ for ceramic coated. Then you need to build a custom y-pipe.

I also have the air gap. It's nice with freer flowering heads and those headers, but the low end torque is less than with the kegger manifold that comes stock...that manifold works much better on higher displacement motors than the 5.2.

If you get that manifold, eq 2.02" heads, the Hughes towing cam, and headers. It'll be a different vehicle...but add another 1100-1300$ to my guess at your rebuild costs.
If i were getting that deep into things I'd just buy a 5.9 short block and build it instead, might even get one that doesn't require a bottom end build.and it usually costs Less than 400$ for a good short block assembly
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Unread 05-10-2012, 06:21 PM   #11
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I would still like to stick with this engine. I guess I might just not get headers yet. I still want to see about getting the intake because I have heard that a lot of people have more power and better mileage with it. So is the towing cam a lot better for lower end torque? Do you know any places that would have any used or remanufactured parts? Also, should the valve springs be replaced too?
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Unread 05-10-2012, 08:18 PM   #12
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The air gap doesn't give those gear results in 5.2's. The power band is shifted to above 2500rpm, instead if 1250-1500 like stock. Mileage gains were not seen on this motor.
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Unread 05-11-2012, 05:43 PM   #13
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How would it work to only change to the towing cam? Is it good for low end torque, or just all throughout the rpm range? I don't really understand what makes each camshaft better for different applications based on the numbers.

Last edited by bmlarson12; 05-11-2012 at 08:38 PM..
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Unread 02-08-2013, 08:28 PM   #14
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I have a 1996 5.2 with a very bent connecting rod and the bottom of piston is broken. Now I wont know about the bores until I get it out but looking up from the bottom of motor the bores look clean. Where can I find a rebuild kit that has the connecting rods with it or do I have to buy seperate? OR where can I find a short block that comes with connecting rods? I looked at mabbco and couple other places for short blocks but none of them say anything about coming with connecting rods.
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Unread 02-08-2013, 10:06 PM   #15
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Quote:
Originally Posted by 72SS View Post
where can I find a short block that comes with connecting rods? I looked at mabbco and couple other places for short blocks but none of them say anything about coming with connecting rods.
a short block is the entire bottom end of the engine. any short block will include connecting rods. the short block includes:
engine block itself
pistons
connecting rods
crankshaft
camshaft
timing set


and probably some other stuff im forgetting. but yes, they all come with connecting rods.
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