Just Empty Every Pocket . . . OR, I need an engine rebuild, anyone know someone good?

[CRCs Reality]

grrrr....

So, my '04 GC with a 4.0, babied from the start with Mobil-1 synth every 3500 miles and every other general 'I care for my engine' work done.. Had been developing the usual 4.0 'tick' over the last few months.. Over the last 2 weeks it's changed from a tick to a full-blown knock.. I've had the Valve cover off and have pretty much eliminated a collapsed lifter, and I've pulled the inspection cover and checked the TC bolts.. Which only leaves (unless I'm missing something) a failing rod bearing..

Now, understand, this is a knock bad enough that I'm scared to drive it at all, neighbors have stopped by after hearing me drive by to ask where I'm having it rebuilt... I'm lucky that we have two cars, and my wife can't drive right now (due to a recent ACL reconstruction of the knee), so I have a car to drive..

What I'm getting at is, I think I'm in for an engine rebuild... Anyone have a local shop they've dealt with for this type of work who they'd recomend? I do most of my Jeep work myself, but as I have no garage, a rebuild is something I'm inclined to 'farm out' and I'd love some suggestions on where to go...

Thanks in advance all

PS - if someone has a good 4.0 they want to part with, I'm willing to listen, I'm fully capable to swap in another motor.. Just don't have the garage to rebuild it.

[2002wranglerX]

The power techs are known for this. Justin had this happen an the motor he put in it blew right after.

[justin'sbig7]

Yes. Long story short There is a connecting rod rod that has a slight bend. The tick starts then goes to a knock as the rod gradually bends more. Then it eventually breaks and knocks a hole in the side of the block. Replace the connectingrods before you have a useless block. I had two do the exact same thing.

[DixieJeeper]

Sorry to hear about the major suckage;

The other thing that GC and XJ's with DIS igntition are know for- (aside from blown head gaskets/cracked heads) are piston skirts cracking. MY XJ had 2 crack, sounds like a tick, then goes to a slight metallic wrap, then eventually to a knock. Not saying you don't have a gonzo rod bearing of course.

If you have a broken or cracked skirt when you check it via cylinder balence test it might even quiet down like it is a bad rod or rod bearing. Only sure fire way to check is drop the pan. Which isn't that bad only 10-15 min... check for chunks in the pan. If there are no chunks then take a light and look up (while wearing some saftey glasses of course) look for sections of skirt broken off.

I was kinda shocked that after a beating early in it's life with me that my 2.5 had broken skirts even too.

Either way sounds like you need a major work but it isn't the end of your GC.

If the GC has been babied, doesn't burn oil, and overall good condition, and has broken skirts, you can just put pistons in. IF the cylinder walls aren't damged or scored.

Pop the head and pan off, take all 6 pistons and rods out, get the upgraded teflon coated skirted rods, have the rods checked and bored, new rod bearings, straight hone the cylinders, and there you go. That is what I did with my 2.5L TJ total cost was about $300 less gaskets.

My best recomendation if you need a rebuild.. contact:

Bob at ICS Machine in Sewickly off Rochester Road NEAR the Sir Pizza (412) 366-1009

He does all my machine work, great quality work, fair prices- tell him Scott from Acura sent you.

He inventories 4.0, 4.2 engines, and rebuilds them and sells them without a core- complete valve cover to oil pan with a 3 year unlimited milage warranty on them. He even can pull and install them for you if need be too- I just sent Dragonslayer from on here I just recommened him to pulled and installed a 4.0 rebuild in his XJ

[The_War_Wagon]

Crate engine from the dealer - 340 V-8 Hemi!

Sorry to hear about your engine going - I'd always thought the I-6 was pretty indestructible.

[Dragonslayer]

Crate engine from the dealer - 340 V-8 Hemi!

Sorry to hear about your engine going - I'd always thought the I-6 was pretty indestructible.

crate V8 from dealer+wiring harness+computer= go buy one that already has it!!!!!!!
The older I-6's are the one's that are "indestructible", the newer one's '99-up have issues and no matter how well they are
taken care of end up failing BIG in the long run.

[gonecheenin]

Can you swap in the older 4.0?

Call Tom the Jeep guy over in Holiday park, he usually has something available that would fix you up.

http://pittsburgh.craigslist.org/pts/2844403345.html

[XJchris98]

The engine guys at DLK in Russellton would be able to help you out. I know they're not the cheapest, but their work is top notch and they know their way around a 4.0L.

http://www.dlkautoparts.com/

[DixieJeeper]

Old 4.0/4.2 are realtively swapable. There are some minor differences. I suppose if you were inclined you COULD swap in an older 4.0 from the junk and slam your manifolds and wiring on.

But you could just rebuild yours with improved parts and not have the headache of a swap. If you used a YJ 4.0 especially and older one would have to ensure you either had all the coolant vaccum switches blocked off or sealed with the old switch, manifolds are different, etc. etc.

The main issues are "powertechs" aren't as sensitive to misfire detection as they could be (they meet the minimum standard for OBD II of course) and I think towards the end of the 4.0 lifespan they cheaped out on some manufacturing processes when they new it was a dying engine platform.

My hypothesis is two fold;
1)the pistons are different from 96-ish/97 although internal specs are the same. I think they went with a cheaper casting which leaves the piston inheirently weaker. Some of early powertechs didn't have teflon coating on the skirt, those that did they weren't as far down on the skirt as the others. Weaker piston/skirt material, with less/no teflon coating means more friction on a weaker material.

2) Now add in that misfire detection isn't the greatest (Im getting long winded as usual so I am not going to go into detail)
2a)and that CMP and CKP sensors tend to fade in and out on without going completely out of spec- just living on the hairy edge of the outer limits t on our rigs and only then ultimately going gonzo.

This all meaning the revolution algorythm of the misfire detection prgram gets eronious data, doesn't set a light/dtc when there is a misfire and you keep motoring on unitl CMP/CKP come back into range or you feel a dead miss that the PCM didn't detect and mitigate.

This all allows a misfire to go undetected straining the weaker pistons, until the skirt cracks, then it splits, then it chunks out, then it goes gonzo.

Thats just my theory.... nothing other than pure talking out of my arse. I came to that plausable explination after talking with a handful of customers and hearing similar stories no light, good verified service history, etc. Coupled with a handfull of my rigs, and engine work on the side- and talking to Bob @ ICS who agrees, and he seems to seen alot of them too go out that way.


Of all the cracked skirt 4.0/2.5s I have brought back to life with replacing cracked skirts with improved pistons and honing or boring if need be; I never had one come back and to the few I keep in touch with have gone 50 60 80K since my engine work without issue.

[shooter207]

Hey, might as well build a stroker. Any decent engine shop can do it and you need some new parts anyway.

There are kits http://jeep4.0performance.4mg.com/stroker.html

Here is a shop that does good work, I don't know if it is too far away though http://www.yellowbook.com/profile/di...853751933.html

Good luck!

[justin'sbig7]

******YOU CANNOT SWAP AN OLDER 4.0L INTO A WJ********

i ran into this as i had 4 old 4.0's laying around. the wj/powertechs have completely different motor mount bosses and block castings. i found this out as i had the blown engine pulled and found that there was completely different accessory mounting bosses as well as the motor mounts that wouldnt work. powertechs can only be replaced with a powertech (at least in the wjs)

[DixieJeeper]

^^^ take his word for it... I never tried.. and just assumed that you might be able to but I don't know why you would. Thanks Justin.

[justin'sbig7]

^^^ take his word for it... I never tried.. and just assumed that you might be able to but I don't know why you would. Thanks Justin.

lol! when i was going through this there was not much to be found on the differences in the blocks via google or anything. i have been accused of being nuts for suggesting theres differences on other sites... i just dont want to see anyone waste their money. easiest and best way to fix is to get a good set of connecting rods and put them in before the block is junk. replacing it with another powertech will just get you another junk set of connecting rods.

[CRCs Reality]

Hey, might as well build a stroker. Any decent engine shop can do it and you need some new parts anyway.

There are kits http://jeep4.0performance.4mg.com/stroker.html

Here is a shop that does good work, I don't know if it is too far away though http://www.yellowbook.com/profile/di...853751933.html

Good luck!

LOL, I'd love to do the stroker build, but as it is I'm scraping to come up with the cash to take care of this.. And from what I've understood, the stroker requires additional mods (oversize injectors, fuel pressure regulator, etc) that I won't have the time to deal with.. I'm inclined to either have it rebuilt, or buy one already rebuilt (ATK, Titan, etc) and have it installed.. The cost seems similar either way..

I'm leaning towards having someone local rebuild it for me (probably the shop DixieJeeper suggested, thanks by the way) just so if something is wrong I have someone local to talk to about it..

[Dragonslayer]

I asked Bob about building a stroker for mine and he said it would be about another $800-$900 additional.
If I had it I would've.

[DixieJeeper]

Hey CRCs Reality:

I think you called ICS today and spoke to Mike after speaking to Bob- they told you 2 week turn around time on your GC engine to pull, rebuild, and reinstall.

Bob just called me- he wanted to cut your turn around time down- since you said your wifes rig is down too? So he went digging and found a good grand cherokee 4.0 core in his wharehouse. If you give him a call and give him a go ahead- he said he can have that core rebuilt, pull your motor, and install in 1 week turn around. He didn't have you number so he can't call you back, so he called me to get ahold of you.

Scott

[CRCs Reality]

Thanks DixieJeeper, yeah I talked to Bob for a while this morning and then Mike a little later.. I sure got the impression he know's his Jeep 4.0 motors, LOL..
I called him back and he's starting tomorrow on a motor for me, I'll arrange a flatbed tow to his shop and he'll take care of my poor WJ.. Seems like a really nice guy (over the phone anyway)

Timing being everything my wife's Altima (our only car while the WJ is dead) decided last night that it no longer likes 1st or reverse gears..... it's been a great month so far

Anything else goes wrong and I'll be looking to sell off my first-born to finance the rest...

[DixieJeeper]

Glad he got ahold of you- hes got a full service shop and does beyond top notch stuff- lot of racing builds too... the shop is sort of unimpressive from teh street but he has EVERYTING inside... i hope the Nissan is ok.

[scramblur]

Kind of depressing to read this. We also have an 04 GC that we bought new. Also Mobil 1, all service, etc, etc. About to turn over 90k. It still sounds fine but this makes me wonder if its time to trade it off.

[CRCs Reality]

Glad he got ahold of you- hes got a full service shop and does beyond top notch stuff- lot of racing builds too... the shop is sort of unimpressive from teh street but he has EVERYTING inside... i hope the Nissan is ok.

Yeah, I dropped the WJ off with him today and he walked me around his shop.. You're not kidding, he has everything.. And he took some time to talk about the issues with that year 4.0 and how to avoid them with better rebuild parts.. Good guy.

The Nissan, However, appears to need a full rebuild of the transmission
Expensive month...

[gonecheenin]

Hard to believe you can't count on the latest gen 4.0, especially with all the good ones we've had! Heck, I'm STILL beating the daylights outta the 250,000-ish mile 4.0 in BigZees old YJ with zero issues!!!

[DixieJeeper]

.....The Nissan, However, appears to need a full rebuild of the transmission
Expensive month...

Well I would reccomend to you Gillece Trans any of their locations- but have used Gillece in Cranberry. They are what I would say on the higher side of fair- but they trans dyno every rebuild... and do really good work. They aren't the fastest as they are always busy.

[CRCs Reality]

Hey Scott (DixieJeeper) . . . Thanks for the hook-up with Bob at ICS.

The problem...


ICS did a great job, and I got my WJ back today . . . . Stupid piston skirt

I can't say enough about the great job he did, he's a good guy.

[Azzy]

whats with the crappy piston skits in the newer 4.0s. Im starting to wonder about the wife's 01.... wonder which will happen first, will the head blow or the pistons fall apart?

[DixieJeeper]

Glad you got it back without issues.

The piston skirt issues is a common porblem... see my post from above regarding my theory and the machine shops owners take on it too.