Hello,

To give you some background, I live in New York and have always wanted a Jeep Cherokee (I owned a Grand Cherokee back in college when I lived in West Virginia).

I decided to purchase a used 2000 Jeep Cherokee Classic off of Craigslist last month with around 100k miles on it. Soon after purchasing it, the check engine light came on and I began to notice a "rough idle". Not being mechanically inclined, I took it to a nearby mechanic.

The mechanic had my Jeep for nearly 3 weeks and was stumped. He tried a lot of stuff, and fixed a few peripheral problems, but could not solve the major issue (the check engine light throws a signal saying there was an issue with cylinder #3, which is causing a shaky idle).

Because I couldn't get the car inspected with the check engine light, I took it to another mechanic. This mechanic had the car for almost two weeks! They also fixed a few minor things, but could not fix the overarching issue.

While the first mechanic basically gave up, the second mechanic sort of identified the issue. He said that cylinder #3 has really low pressure (70 pounds of compression when heated, and something like 110 after putting oil on it).

The owner of the second mechanic shop said that I should drive the Jeep for a year and then get rid of it. The mechanic that actually worked on my Jeep pulled me aside and said "I would get rid of this Jeep as soon as you can, and I would *not* drive it the 500 miles back home to WV for the holidays".

Now, I am not very good with cars, so I am shy on details, but considering you all on this forum are experts, I would like your input.

Please let me know if you think I should keep this vehicle (and pay to have it fixed), if I should get rid of it now, or if I can drive it for a year before getting rid of it.

Thanks again for your time and your input!

- Ian


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2000 Jeep Cherokee Classic

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Tasks completed by mechanic #1:

1. replaced a/c compressor
2. recharged a/c system with freon - oil edge
3. clean computer pins at harness
4. diagnose check engine light code P0303 3.0
5. remove and replace #3 fuel injector
6. replace ignition coil pack to test for #3 misfire - no change - removed
7. p/w lock out - individual windows wont operate from source
8. clean the throttle body
9. remove valve cover to check the rockers for full movement
10. replaced temporarily the throttle body & the idle control motor

New parts that were purchased:

1. new a/c compressor
2. new spark plug
3. new fuel injector
4. lock out switch

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Tasks completed by mechanic #2:

1. search wiring harness for shorts
2. probe sensor for voltage drop
3. smoke test entire vacuum system for its integrity

New parts that were purchased:

1. replaced computer

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Outstanding issues:

1. #3 compression 70lbs when heated

 

You bring in a misfire, and he replaces the AC compressor? WTF?

Do some reading here

 

I'll give ya $50 for it, right now....
LMK

 

Rebuild the motor or replace. Get a used motor

 

Thanks for the link, there's some good reading out there.

As for the replacing the AC compressor, evidently it wasn't turning correctly, thus causing the belt to rub which would eventually lead to it snapping (leaving me stranded).

The bit that has me frustrated is that the first mechanic basically shrugged and gave up (after 3 weeks of trying), the second mechanic registered my jeep but in the same breath advised me to get rid of the thing ASAP. If the #3 cylinder has low compression, and adding oil to it boosted the lbs from 70 to 110 or so, you'd think they'd want to look into replacing the rings. Probably not worth their time, thus making it easier to just send me on my way.

My old college roommate was a mechanic at a Jeep garage for a lot of years, so I'm hoping to drive it the 500 miles back home so that he can take a look at it.

As for the $50 offer, that's tempting, but I think I'm going to have to sleep on it...

 

I think you're right, peckerwood. Sad, but true...

Do you think it makes sense for me to drive it the 500 miles back home to my trusted mechanic? Or am I going to end up stranded on the side of the road somewhere on I-68?

 

How does the engine coolant look and does the vehicle consume any?

 

I dont think you'd end up stranded on the side of the road. It just isn't making enough compression in the number 3 cylinder to burn the air/fuel charge. It will just essentially run on 5 cylinders.

 

You won't be stranded. Like said above it will run just on 5 cylinders. The fact that it has good compression when oil is on top of the piston means that the piston rings are bad so it just wont seal. It will probably burn a little more oil and will deff run rough but based on what you said it should get you around. There is a small chance that the piston rod could break but not anymore likely than driving a good 4.0 with 100k on the clock. Drive it like you stole it untill you can reolace the engine.

 

Is coolant disappearing? Is the engine oil muddy or milky colored?

These are the only things that matter right now. Also you might want to tell people to stay away from mechanic #1, that guy took you for a ride BIG TIME.

 

As a quick update, I asked my friend Matt to take a look at my Jeep. He's owned several Cherokees and was a mechanic at a Jeep dealership for many years, so he really knows his stuff.

After inspecting my Jeep, he says that the issue isn't mechanical, but instead it's electrical. To start, he swapped his computer out of his Cherokee and put it into mine. This resolved part of the issue, but we're not totally out of the woods yet. When you reset the computer, the vehicle drives just fine for 50 miles, until the adaptive learning kicks in. Then, there seems to be some sort of issue with with the Jeep "learns", because the check engine light comes on and it throws an error that says there's an issue with cylinder #3 (it also throws errors with different cylinder numbers too).

My friend thinks there's an issue with the PCM plate or maybe the crank sensor.

He's going to take a closer looks this week, hopefully there's a clue there that can help get to the bottom of things...

 

Is coolant disappearing? Is the engine oil muddy or milky colored?

PCM swap isn't going to solve any cracked heads.

 

WOW! This has been asked 3 time without any response. He wants help but wont give any info back. TO the OP, This question is very important since your year came with the 0331 head and is known to crack.

 

I had the same problem with a 2001 I just bought. I got the head replaced since it was cracked (not cheap). Drove it for about 75 miles and check engine light came on again. Going back to mechanic tomorrow. Any suggestions please let me know. Thanks

 

Hey everyone,

Very sorry for not directly replying to the questions posed in this thread. I answered them in my head, but forgot to actually include the necessary info in my reply!

You all are correct, the 99-01 Cherokee engines are definitely prone to head cracking. My buddy's in fact cracked and he had to swap it out with good head.


My friend and I already looked into this idea already. My oil is normal and my coolant level is good. I'm also thinking that a cracked head wouldn't cause the electrical issue that I'm seeing. That being said, it would be at the 3 cylinder, so I can totally see why this could be a potential cause.


I'll reply later with some additional information to ponder. Again, thanks to everyone for scratching your heads on this one with me.