97 Cherokee 4.0 Rough Idling

[hillbillyman06]

Hello All! I am new here so give me a little break if I miss something.

Ok I know this is probably an on going question on here but I don't want to dump a whole lot of money in this thing...ah I guess I can afford it since the guy I bought it off from told me it had a blown motor in it, I got it home and put a new battery in it held it to the floor and she fired right up after sitting for more than a year.

So at first I figured TPS, nope cause now it fires up without putting it to the floor. Changed Plugs,wires,cap,rotor and found that one of the injectors was bad so I replaced that. It still sounds like it is only running on 5 cylinders and I am getting alot of black stuff coming out of the tailpipe.

o2 sensor? Converter? any Ideas?

Thanks in advance for the help.

Also got an Awesome 04 GCL w/V8 4.7L

 

[wstall77]

My 96 did that when the O2 sen went bad. I wound up replacing both instead of trying pinpoint it to 1. My mpg's were cut in half too... don't guess you really know bout yours...I have always been told that if you tap the converter with a hammer and it sounds like it has rocks in it, that its bad. But thats just what i heard. I also have a haynes manual that shows how to check all the sensors.. If you don't its well worth the 15 bucks. Just my 2 cents. hope this helps

 

[hillbillyman06]

Thanks for the info..I got a manual the other day and was under it looking at the front sensor and noticed that were the pipe connects to the manifold it is crushed over half way..so I am going to take that off and get it fixed and see if that will straighten it out a little bit, also replacing the O2 sensor at the same time.

 

[wstall77]

Is the exhaust crushed right at the flange where the manifold meets the pipe???? Mine is the same way!!!! thats odd. I have no idea how it was possible to be crushed there but it is!! If correcting this problem helps any at all please let me know. Mine has some unresolved misfire issues that are bugging me!

 

[hillbillyman06]

I looked at a 94 and it is the same way, so I guess that is how they were made...Odd, you would think that would create a problem..

 

[Jeepr]

They are all crushed up there. I always thought it was weird too.. I dunno??

 

[hillbillyman06]

Well thought I would post an update on this.....GOT a blown head casket..didn't notice it until last night changing the valve cover casket because it was leaking...and low and behold there it was all over the rocker arms ole nasty milky oil. Oh what fun this is going to be.

 

[90Xjay]

have you torn into it yet?

 

[hillbillyman06]

yeah..got it down to the head..waiting on gaskets (for over a week now). Might have to change auto parts stores. I will post an update probably monday.

 

[90Xjay]

oh man, no one had your gaskets in stock:x

 

[hillbillyman06]

Pretty big update here....Got the head off and noticed something pretty bad besides the blown headcasket...2 bad pistons and I mean bad...ended up pulling the whole damn motor and pulled out number 3 piston it has a dime size hole blown right thru the side of it...Just going to look around for another motor now...I am really amazed at these 4.0L motors..that thing ran great when you got it above 2200 rpms and another thing I would like to add it was running mostly on water instead of oil...pretty amazing it would still run...one word for it....TOUGH!!

Anyone know of any good deals on motors in PA area??

and 90 where abouts you live in TX? I lived in Lufkin for 5 years...and loved it!

 

[90Xjay]

Pretty big update here....Got the head off and noticed something pretty bad besides the blown headcasket...2 bad pistons and I mean bad...ended up pulling the whole damn motor and pulled out number 3 piston it has a dime size hole blown right thru the side of it...Just going to look around for another motor now...I am really amazed at these 4.0L motors..that thing ran great when you got it above 2200 rpms and another thing I would like to add it was running mostly on water instead of oil...pretty amazing it would still run...one word for it....TOUGH!!

Anyone know of any good deals on motors in PA area??

and 90 where abouts you live in TX? I lived in Lufkin for 5 years...and loved it!

Man, sorry to hear about your motor...
I hope you find a deal or get yours rebuilt at a good price.

I'm about 2 hours west of Fort Worth on I-20, Taylor County.

 

[heminut]

My guess would be at least 2 broken pistons.try doing a compression test before disasembly and if 2 ajacent cylinders are low,maybe its just a head gasket.If original oil still in pan,take it to kendall labs in bradford Pa . as they are very good at analization and sometimes even tell you what parts broke.

 

[wstall77]

I bought my jeep cause of a friend in high school! He was so damn hard on that poor thing but you couldn't kill it! 350K and still running! I think its a 94. I live in TN and you can get a motor at a salvage yard here for about $500.00, with about 100k. I had my motor rebuilt/modified for $1500 and it was well worth it!! Good luck.8)

 

[hillbillyman06]

Got a new motor (70,000 on it)...it is on the road and running great..Sold it to my Sis in law because she rolled her Dodge awhile back....and needed reliable transportation so what better than a Jeep!

 

[wstall77]

congrats!!!!!!!!!!!!!!! So i guess you are in the market for another jeep!!!

 

[hillbillyman06]

well I already have a 04 Grand Cherokee, but if I can land a deal like on the last one...I will definately buy it.

 

[1989hog]

You may want to get a Compresion tester also , they are very easy to use, cheap to buy and can narrow your problems down alot. Gives you a good starting point.

 

[1989hog]

not to mention it gets you to take out the spark plugs out and they alone tell you alot of how your motor is runnin