And they say the 4.0 Jeep is bulletproof!

[nylyon-(Admin) 7,247]

Last winter, during one of those super cold days, I started up the Cherokee (because the diesel had gelled) and took a kid to cheer practice.  On the way home I heard a really loud and bad knock.  I parked the Jeep and really didn't get motivated during the summer to fix it.  Well, this weekend I got it torn apart and this is what I found!

 

 

I've ordered up 6 new plugs, the rest of the engine looks really, really good.  No sludge, everything is clean, can tell it was maintained.  Turns out that the 4.0 is NOT as bulletproof as you would be led to believe since this is a relatively common problem.

[Ed Kennell 38,007]

No damage to the cylinder ?   Maybe it is bullet proof.

[Ken B 3,164]

There is ALWAYS a few...  Its a bummer that it had to happen to you. I have owned at least 4 4.0 Jeeps and they have all done very well for me. My current 2002 Jeep Grand Cherokee has 179,000 miles on it. I have taken great care of it so it still looks like, runs new too!

[Geno 1,929]

I've seen quite a few like that in the shop over the years, that's why the ones I've owned I've tried to stick with the 318.  Now that engine is tough. 

[chazm 413]

Karl.. how many miles on it, I got a 94 with 250000 on it. just looking for a time frame mine might cry for help

[nylyon-(Admin) 7,247]

The cylinder is fine, no scratches at all and still has the hone marks in it.  The Jeep has about 120,000 miles on it and has been well maintained mechanically.  From what I am reading, this is a 1998 - 2002 issue mainly.  I bought it about 8 years ago and it's had all the common issues (track bar, shocks, intake gasket whistle, radiator, heater core etc).  I had hoped that it would be more robust, but as the common ailments arise, the aftermarket fixes them permanently. I spoke with a guy who had a 2001 Grand which had the same thing.  He replaced the engine with a junkyard one and that one did the same thing after 10K. 

 

It's a good Cherokee but not the kind that the off-road crowd like because it has the weaker axle's, select trac and such.  But for a street driven Jeep it's perfect because the select-trac has full time 4wd which is perfect for this time of year with leaf slippery roads and the heated leather to keep the touchy warm in the winter. 

 

I had contemplated replacing it with something else, but it'll cost less to repair and who knows what I would inherit from someone else.

[KyBlue 655]

You'll get it lined out and be better than the factory could have done.

[nylyon-(Admin) 7,247]

Well all the parts are ordered and I took next week off from work to finish everything up.  When that's all done, I start work on the 312-8.  I couldn't in good conscience work on a tractor while the Jeep was out of commission!

[stevasaurus 22,700]

You going to replace all the pistons Karl??    Good call on the Jeep before the Horse. 

Edited October 28, 2014 by stevasaurus

[nylyon-(Admin) 7,247]

I was originally going to replace just one, but I'm really getting too old to jerk with this stuff, so they're all getting replaced.  The rod bearing looked NEW, I've never seen one in such nice condition.  I think that it's going to last a long time with 6 new pistons.

[19richie66 17,498]

My daughters 2000 jeep has 230,000 on it. No smoke but does leak oil. It has a leaking valve cover and hopefully thats the last I have to do to it for a while. I just put a fuel pump in it, radiator, hi flo water pump I had left from mine I never used, and a crank sensor, oh and a new coil pack, ecm, injector o-rings and fuel rail supply pipe, belt, headliner. Lol. Not much left to replace. She went to a friends to stay for a week and was supposed to leave her jeep at home so i could do the valve cover gasket but no..... She left it at her friends in thier barn. Rat decided to chew on her wiring harness at the #4 injector. Wires touched when she got back and drove it home. Shorted the ecm injector driver for that cylinder. Bought one used that was plug and play, HA HA. She has the security key option. Put old ecm back into the jeep and off to the dealer we go. $142 later it was programmed. While it was sitting in the mechanics bay(which was a friend of mine), the coil pack shorted. Off to napa for a coil I could afford. Drives it for a week and dies in school parking lot. Replaced the crank sensor while all her friends watch. 3 days later it starts leaking at the radiator tank seam. New radiator in and 2 days later, stalls at the gas station. I get it going and drive it home. Shuts off twice. Get it going and haul butt down the road and the hood flies up. Bends the bottom edge. But I did find the missing plastic piece for the injector wires i was looking for. It was jammed in the bottom of the hood lip. They are both black so you couldnt see it. Stalls 1/2 mile from the house and wouldnt do nothing. Towed it home with the C-81. Fought it for three days. Found a broken wire going to the coil pack behind the head. And I wonder why I dont get any tractor stuff done?

Edited October 28, 2014 by 19richie66

[Racinbob 11,035]

I'm seeing a problem here Richie. You didn't post a picture of your C-81 towing it home

[nylyon-(Admin) 7,247]

Well -- Spent the day today cleaning up the head, deck then installed the rings on the pistons, new bearings and popped them in the cylinders. Got the head on and torqued, and re-installed the push rods and rockers. 

 

Hoping that I finish it up tomorrow and can cross it off my list of things to do.  Looking forward to getting it OUT of the garage, so the new car can spend the winter in there instead of the old one!

[stevebo-(Moderator) 8,330]

Lots of work over at your place on that Jeep. Hope it continues to go well...

[Coadster32 793]

Surprised that no other damage happened considering the picture. I agree and good call on replacing all of them while it's apart.

 

I'm sure others would help you out,..but everyone up your way is over @ Steve's building a barn.

[AMC RULES 37,126]

  Refer to post #2. 

[squonk 41,016]

My daughters 2000 jeep has 230,000 on it. No smoke but does leak oil. It has a leaking valve cover and hopefully thats the last I have to do to it for a while. I just put a fuel pump in it, radiator, hi flo water pump I had left from mine I never used, and a crank sensor, oh and a new coil pack, ecm, injector o-rings and fuel rail supply pipe, belt, headliner. Lol. Not much left to replace. She went to a friends to stay for a week and was supposed to leave her jeep at home so i could do the valve cover gasket but no..... She left it at her friends in thier barn. Rat decided to chew on her wiring harness at the #4 injector. Wires touched when she got back and drove it home. Shorted the ecm injector driver for that cylinder. Bought one used that was plug and play, HA HA. She has the security key option. Put old ecm back into the jeep and off to the dealer we go. $142 later it was programmed. While it was sitting in the mechanics bay(which was a friend of mine), the coil pack shorted. Off to napa for a coil I could afford. Drives it for a week and dies in school parking lot. Replaced the crank sensor while all her friends watch. 3 days later it starts leaking at the radiator tank seam. New radiator in and 2 days later, stalls at the gas station. I get it going and drive it home. Shuts off twice. Get it going and haul butt down the road and the hood flies up. Bends the bottom edge. But I did find the missing plastic piece for the injector wires i was looking for. It was jammed in the bottom of the hood lip. They are both black so you couldnt see it. Stalls 1/2 mile from the house and wouldnt do nothing. Towed it home with the C-81. Fought it for three days. Found a broken wire going to the coil pack behind the head. And I wonder why I dont get any tractor stuff done?

And people wonder why I gave up working on cars. I was working at a Chevy place in late 80's to the early nineties and they acquired. AMC Jeep. Renault They were bad enough but then came the Eagle Medallion and Premier. Talk about junk!  

[nylyon-(Admin) 7,247]

I've been taking a slow approach to this.  Each day I set a goal and anything above that is great.  Yesterday unfortunately, I only did what I set out to do.  Today's goal is button up the underside (oil pan, starter etc). I have to wait for the big brown truck to come as I have a new fan clutch coming.

 

Has anyone else had bad luck with aftermarket fan clutches?  I replaced this one a couple years ago, and the thing never disengaged, at around the same time I replaced the one on my 300ZX and that one never ENGAGED!  OEM is so expensive, but I am hoping that it's at least going to WORK!  Well finishing the coffee, then off to the parts store (hopefully for the last time on this thing)

[Geno 1,929]

I've been having trouble with aftermarket parts for about 5 years, some longer than that.  Each parts house has differing quality of some parts also.  It seems over the past few years between the choices here of Advance, Autozone, Carquest, NAPA, and O'Reilly that O'Reilly generally seems to have the least troublesome parts.  I haven't had any problems out of their fan clutches.  

[Ibuprofen 2]

My 96 Cherokee had 160k and some change on it when I traded it in. My mother had it before me and the only thing we ever had to replace was a water pump and a fan belt. The catalytic converter sounded awful at start up (rattle) though. Ironically enough we got a recall on the cat a few months after we traded it in. It was slow and didn't ride very well but it was dependable

[nylyon-(Admin) 7,247]

Well, pushed hard and got it finished up.  I didn't replace the plugs, and it has a hard miss on #3.  P0303 so new plugs tomorrow.  I don't think it can be anything else since I didn't touch the injectors.

[Geno 1,929]

Did you unplug the injectors? 

[nylyon-(Admin) 7,247]

Yes, I did unplug them.  I reseated #3, same thing.  Too tired to mess with it today, tomorrow I'l put in 6 new plugs.

[squonk 41,016]

Make sure there there isn't a missing or cracked vac hose on # 3's intake runner. That will lean that cly. right out.

[Ken B 3,164]

My 96 Cherokee had 160k and some change on it when I traded it in. My mother had it before me and the only thing we ever had to replace was a water pump and a fan belt. The catalytic converter sounded awful at start up (rattle) though. Ironically enough we got a recall on the cat a few months after we traded it in. It was slow and didn't ride very well but it was dependable

I had 240,000 on my 91 Cherokee Sport when I decided that it was time to let it go. It was used to tow my 20 ft. camper, my boats and tractors for many yrs. and it NEVER let me down.. I always swore I'd drive it right into the ground but I gave up on it before it did on me. The biggest thing for me was after a long day of boating (sometimes 3 hrs away) it was getting to be much to uncomfortable for my aching back. It had little things wrong with it but the biggest thing was the rear main was leaking pretty good. Not a real biggie too fix but not on my priority list. I put it up for sale for 1000 bucks but it seemed the only people interested in it was recently divorced women with little to know money! I couldn't sell it to them in good faith, I was really hoping some Jeep Junkie would buy it. When that never happened I decided to junk it. I drove it to Novella's junk yard and he gave me 650 bucks for it! I will say mine wasn't slow, the 4.0 H.O. would get up and boogie and would actually smoke the tire's...

Well, pushed hard and got it finished up.  I didn't replace the plugs, and it has a hard miss on #3.  P0303 so new plugs tomorrow.  I don't think it can be anything else since I didn't touch the injectors.

Nice job Karl.. You'll get it sorted out!