Jeep Cherokee Grand Cherokee Engine and Performance Problems



  • mimi139mimi139 Member Posts: 9
    I was wondering if anyone had a problem as mine with a 2001 Jeep GC. I drove on the highway a pretty long distance and went to grab something to eat thru a drive thru when my check gage light went off and chime. I looked at the gage for heating and it was almost close to the red overheat area. I shut off the jeep waited about a minute. Started the jeep and pulled along the side of the lot. it almost sounded like water boiling but louder. I waited about 20 minutes and then started the jeep the gage went to appx 240
    and I started to drive home (a few blocks away). I shut the jeep off at two red lights to prevent from over heating. Any idea what can be going on?
  • mullins87mullins87 Member Posts: 959
    It could be nothing more than your thermostat, easy fix. If it overheats only when sitting still or driving slowly, then chances are it's the cooling fan. If it overheats all the time, even when driving at highway speeds, then it's the thermostat or the water pump.
  • mullins87mullins87 Member Posts: 959
    HOLY COW!!!!! This is a new one on me. The only time I've ever heard of something like this happening is pounding the Jeep really hard offroad. So, was the input shaft all chewed up?
  • mimi139mimi139 Member Posts: 9
    The car cooled off about two hours and I decided to go three blocks to the store. Came back and sat in the car with the heat up high the radiator fan did not kick in at all. The gage went up I think it was like 220 and the fan did not kick in. I am thinking it is the relay for the radiator fan, but not sure because that was replaced sometime earlier this year. I educated myself with this forum by reading and surely saved alot of money because a shop told me to have the fan replaced. :blush:
  • mullins87mullins87 Member Posts: 959
    If it is the fan relay, again, then you should be able to drive it at highway speeds without overheating.
  • mimi139mimi139 Member Posts: 9
    thanks :)
  • jeepachejeepache Member Posts: 8
    not at all that is what is so strange..well its over with now cant wait till the next fiasco with it:) Thanks for your insight it always helps
  • joemammmajoemammma Member Posts: 2
    Im so glad I found this msg board cuz I'm having the exact same problem. Last week while driving to work in my 98 Jeep GC, I was at a stoplight and all of a sudden car dies. Try to start and it cranks and cranks, but won't start. Tried this for about an hour w/ no luck. Finally had to call a tow truck and tow to shop. I was relieved to find out it was only a crank something sensor that went out and wasn't that major.

    OK so here's the strange part.....2 days after getting car out of shop, today in fact I start the car and it is idling rough. Thought maybe the engine is just cold, but no, it kept on idling rough and sputtering as I accelerate. Thought it would go away but it's getting worse, to where it's almost knocking and feel like it's about to die. It's worst when I come to a complete stop, then it will idle real rough and almost shake/vibrate the car. I have to put it in neutral and then it will lessen the knocking. Then when I go, its sputtering again only louder each time. All this again after 2 days of the other repairs.

    So I bring car back to shop and he puts it under scope/pc....which say something like " ignition distributor engine module malfunction". My mechanic resets it and test drives it and says it either another sensor under the distributor that regulates air/fuel, or it's just high mileage on the vehicle (180k). So question is what should I do? I feel the shop is responsible cuz it only did this after I got my car out. And I don't think high mileage can turn my engine to the condition it is in now and so rapidly all in one day. Last time I drove car I smelled a burning smell coming from the engine. Afraid to drive it again.

    Thanks for listening and any advice would be appreciated.
  • jeepachejeepache Member Posts: 8
    they replaced the crankshaft sensor ..this devices tells the computer when the engine is at Top Dead Center (TDC). The mechanic cant tell you what sensor is bad?...sounds kind of iffy.
  • mullins87mullins87 Member Posts: 959
    Your mechanic should be able to at least have an idea what's going on, that is if he/she is a competent mechanic. A code scanner can point you in the right direction. Any engine with that many miles on it is subject to exactly your problem. Sensors can go out immediately and without warning. It is possible the Crankshaft Position Sensor was not installed properly, therefore it could have shifted and is sending the computer incorrect information.

    Your problem could be any number of things. I would have the codes pulled, they should point you in some direction. I would have the CPS looked at again, just to make sure it was installed correctly. Other than that, follow where the codes lead you.
  • joemammmajoemammma Member Posts: 2
    The code is P0320 "Ignition/Distributor Engine Speed Input Circuit Malfunction".

    After doing some research I think most likely it is the TPS Sensor or the Crank Sensor installed incorrectly which can effect the Cam Sensor inside the distributor.

    I had no choice but to drop the car back off at the shop on a Sunday and left keys w/ gas station b/c the car is really undriveable. Now only thing is I'm trying to say it's their fault cuz it really is. This never happend before. Any input?
  • myersflyermyersflyer Member Posts: 1
    ok I have a 1985 jeep cherokee with a 2.8 v6 and an automatic trans. Has anyone ever changed this motor and trans to a chevy small block and a 350 tbo trans with a 208 t-case or a 231 t-case and do they make a conversion kit for this or do i have to make all my own mounts.. Thanks for your help
  • taggstaggs Member Posts: 1
    I just totalled my 05 4x4 ram with hemi.. I want to put the hemi and trans in my 96 grand cherokee larado. Anyone attempted this before that could give me some heads up? Thanks, Taggs
  • mullins87mullins87 Member Posts: 959
    It has been done. Someone pointed me to an article about it once, but I can't remember where it was. Do a search and see what comes up. If I remember correctly, the tranny bolted up to a 231 t-case with an adapter plate.
  • wfs340wfs340 Member Posts: 1
    Your problem is the radiator fan relay switch. It cost $61 at NAPA. I just did my 03 Grand Cherokee. You have to take off the front bumber cover and the passanger side headlight assembly to get at it. Boy you'd think they would have a recall on this part. My truck only has 42,000 miles on it. Good luck, Bill
  • trainhorntrainhorn Member Posts: 1
    I have a 2002 Jeep Wrangler with a 2.5 engine. The other day the gauge went to Zero and the check gauges alarm came on. I stopped checked the oil level and engine heat,everything was OK. I was told it was the Sending unit,easy to replace and cost me 50 bucks,but later the same day it did it again. I hate to spend another 50 bucks with out knowing if this will fix it. Any suggestions?
  • korn18779korn18779 Member Posts: 1
    I have a Jeep Grand Cherokee 2002...when I stopped at a light, the check gages light went on and the oil pressure gage was at 0...Put it on P and whenever I stepped on the gas it would go up to normal levels...but would return to zero whenever I stopped...I stopped at a gas station and checked the oil level...although it was fine.. I put 1qt of oil...then drove it for a few more blocks and stopped giving me problems....Any ideas???.
  • jonesy2285jonesy2285 Member Posts: 1
    I've had the exact same problem, any luck figuring it out?
  • flajeep95flajeep95 Member Posts: 4
    Same thing happened to my 95 Cherokee 4.0 but in reverse order. 1st the meatheads said it was something in the distributor..replace it..beep it dies again. 2nd...They did a complete tune up, new plugs wires etc......beep...dies again this time they replaced what the problem was in the 1st place ...The crankshaft positioning sensor ....small thing mounted on top of the bell housing on the drivers side. I'm in the wrong business.
  • 96_orvis96_orvis Member Posts: 1
    I have the same problem on my 96 GC Orvis.. what i did was i change the oil and i change the Oil Filter.. i use the Fram Double Guard Oil Filter from walmart .. and the problem dissapear.........
  • adrenalicadrenalic Member Posts: 1
    there is a red(orange) clip that needs to be released inorder to disconnect the wire from the sensor. Any idea how to do this. it seems impossible from above ( I can't even see it). from below I can see only one side of the red clip. I located a similar clip in another easier location and found that one side of the red clip has a small tooth that needs to be moved to one side and dislodge the clip. but even there, I didn't know how to remove the clip completely without putting too much pressure( which I didn't want to risk breaking it). does that cliup need to be removed completely to unplug the wire from the sensor. any help is appreciated.
  • cholinacholina Member Posts: 1
    Our 2001 JGC Laredo has 119,000 highway miles and had so many problems including the "shaking" at 24K miles (now a class action lawsuit). The "low coolant" light came on, we've put coolant almost every other day, no leak observed, did not have any burning smoke either. The Jeep dealer said cylinder head #3 is bad, they replaced cylinder head, gasket, oil change, new coolant, spark plugs and thermostat for $1,900 (they kept the Jeep for 1 week). The day we got the Jeep bank, the "engine light" came on, brought it back to the dealer that same night, the dealer could not find the problem and just reset the code. 2 days later, engine light came on again and we returned the Jeep, now dealer says it is the catalytic converter which was contaminated with the coolant/oil mixture. Another $1,100. We have 4 cars ad keep tabs of all maintenance & repairs (Toyota, Honda, Nissan and Jeep GC Laredo) and I can say this Jeep is the worst of all. Needless to say, my family ( and kids) will never buy any Jeep again!
  • coderedcodered Member Posts: 43
    hi i too neep help....we have a 96 5.2 with no oil pressure when heats up...tapping from top of motor when hits 0 psi.....replaced oil pump,sending unit this year....found egr valve hose was broke not sure what it will do .....any help would be great.....
  • captinhectorcaptinhector Member Posts: 2
    Same happened to me, only I was doing it in my backyard. My Jeep wouldn't roar to life after I spent a day in the dirt replacing a craptacular stock clutch/flywheel with a HD set. I went to start the beast and nothing happened, so I went and checked everything, then found the leads for the sensor just hanging there. Replaced it and now, 3 years and about 75k mi later with 175k on it total, it still does its job and now it even hauls cattle on the side!
  • coderedcodered Member Posts: 43
    what is this "pig-tail"...i read about????? :lemon:
  • niteskystarzniteskystarz Member Posts: 1
    So how quickly do I need to do something about the gauge....I had the oil changed 10-8-06 and I am not near the mileage for a new change. I checked the oil and everything is fine as far as levels it just a bad gauge? Can I wait, should I wait, there is a lot going on right now and later in January would be better for me...Is there something I can do my self, remember I am not-so-helpless female. All help is appreciated....
  • gaanelgaanel Member Posts: 1
    Where is the sending unit for the oil pressure located on teh 2002 Jeep Grand Cherokee with the 6 cylinder engine?
    Does anyone know why my pressure would suddenly shoot from normal to max pressure? Would it be the unit or the gage?
    Also, someone has said that there are different sending units, some with 1 prong some with 2. What does the 2002 Jeep with 6 cyl take?
  • mrrydermrryder Member Posts: 1
    This problem just started. The colder it is the harder it is to start. Once it warms up it runs great. Any ideas. Has had plugs and wires recently as well as throttle body cleaned. 4.0 Litre engine.A friend told me it could be the PCM. Would like to know diagnostic procedures to check PCM. Thanks
  • jeepachejeepache Member Posts: 8
    First thing I would do is buy the haynes repair manual for your vehicle it is a good guide and has alot of step by steps and troubleshooting guides. My experience leads me to believe you have a fuel problem either low fuel pressure or a faulty fuel pump. I dont recall off the top of my head if that motor has a cold start injector but it would be worth looking into it. Once again first step would get the repair manual it has some good ideas on it.
  • omislieblingomisliebling Member Posts: 1
    It started when the fan blew up and we replaced it with an aftermarket fan for a couple of weeks, then took it to Jeep and had a "jeep fan" installed, shroud and thermostat replaced. In the meantime there is a recall for the exploding fan problem which Chrysler refuses to pay due to Jeep telling them the problem was the aftermarket fan, they just forgot to mention why we put an after market fan in, so Chrysler is not going to reimburse. On a recent 13 hour trip that turned into a 24 hour trip our Jeep overheated and we had it towed to the closes service station where they found nothing wrong with it so we took off again and not all the time but out of the blue the Jeep overheated while we were driving and most times temperature went down when we stopped, even with the engine running. So we took it back to Jeep and they replaced the thermostat. On the way home it overheated again, we pulled over and shut the engine off to let it cool. Once we started it was fine so we took off again and it overheated as long as we were driving but temperature keeps coming down when we come to a stop. So we just replaced the thermostat again and flushed the radiator and it's still not solved. As we took it for a test drive it overheated and the hoses were hard as a rock. After letting it cool down we started to drive home and it was overheating again but when we pulled into the driveway the temperature went down to normal and the hoses were soft. Jeep can't explain the problem and we don't know where to go from here. Hope somebody out there can solve this mistery and maybe also give us a lead on how to get reimbursed for the fan explosion recall Chrysler is refusing to pay.
  • maddysmom1maddysmom1 Member Posts: 1
    Hi hopefully someone can help me out my Jeep is overheating all the time even when driving and sitting at a light. Also my heat keeps coming out cold and warm and its making a weird noise sometimes. The thermostat is saying its in the red but i've only been driving for 2 minutes or so. If anyone out there can help me out i would greatly appreciate it. Thanks a bunch.

  • poconojeeppoconojeep Member Posts: 4
    I'm having the same problem with a 2001 Cherokee that's just shy of 100k. Oil pressure is fine when cold or when I've got my foot on the gas. As soon as I stop, it drops, and if I'm stopped long enough I get a check engine light. Had it at the garage today and they checked the pressure and were getting a low reading at idle, which I guess means it's not an easy fix like a sending unit. Their diagnosis was maybe oil pump, but they couldn't guarantee and were giving me quotes on a new engine. I've seen lots of posts here and elsewhere of Jeep owners with the same problem, but so far no overriding solution. Has anyone found one? I cannot afford a new engine. In fact, right now a Toyota is looking awful tempting.
  • parkerjdparkerjd Member Posts: 1
    This started a couple of weeks ago. I have a 2000 grand cherokee 4wd 6cyl, great truck. My oil pressure gauge reads all the way to the right which is 80. This happens after starting the jeep. The gauge will read 80 with only a slight movement. The jeep still seems to run fine. Does anyone have an idea on how to fix this?
  • csamy2csamy2 Member Posts: 2
    my 2001 grand Cherokee has the same problem. I talked to a mechanic and he told me that it was probably the oil pressure sensor and told me to let it idle in park for 15 mins and if there is no knocking or valve noise that it's the sensor. I did it and there was no noise so now all I have to do is find out where the darn thing is so I can change it.
  • poconojeeppoconojeep Member Posts: 4
    I think the sensor is right near the oil filter, at least I saw something that looked sensor-like when changing my filter yesterday. I'm not sure if my old filter was loose, didn't seem like it when I fought to get it off, but after putting on a new and higher quality one the problem has lessened. My oil pressure is still dropping when I idle, but not low enough to make the check gauges light come on. This seems like way too easy of a fix so I am still holding my breath.
  • pliskinpliskin Member Posts: 5
    Check out the thermostat as well as the cooling fan relay. I had this problem and it cost about $250 to fix, well worth it.
  • pliskinpliskin Member Posts: 5
    My 2001 JGC Laredo is making a high pitched winding noise when my speed reaches 25+. It sometimes starts & stops. I sometimes think it has to do with the weather. But it is loud & anoing. I've checked all front end fluids & don't have any leaks. DOE'S ANYBODY HAVE A CLUE??? To another Jeep Problem????!!!!!
  • tuggajbtuggajb Member Posts: 646
    change sencor first do it yourself sounds as if the are out to get you if no engine noise at idel probly oil pressure is ok only need 15 lbs at idel on straite 6
  • jlamonsnwajlamonsnwa Member Posts: 3
    I have a 93 Jeep Cherokee with about 120K miles. I have done maintenance since the Jeep was new and it is generally in very good condition. 60% of the time the engine starts within a few seconds and runs great, but 40% of the time the Jeep is more difficult to start and then the engine will continue to run very poorly (tends to miss,hesitate,and backfire). Even a few minutes later the Jeep might run fine. I had drained the fuel, replaced all filters, and replaced all the typical ignition parts. Still the same.

    Since then I found if the ignition switch is turned all the way off then back on the problem may clear (even when driving the Jeep). If the engine starts to miss I can turn the ignition switch off and back on and often the engine will start back immediately and run fine.

    I considered changing the ignition switch but I know there is a lot more relays and such which also could be cycling off and on with the ignition switch.

    Does anyone know a test point I can monitor key voltages from the ignition switch. There has never been an engine error code which made me think the ECM is involved.
  • csamy2csamy2 Member Posts: 2
    After trying all the car parts stores in town I finally had to go to the Jeep dealership to get the oil pressure sensor. Had to buy a deep well socket too. Of course it snowed today so my car was covered. I took it to heated building to work on it. It wasent that hard to do after I figured out I had to take the oil filter off first. Now I have 55 psi of oilpressure while driving and it never drops below 40 psi when I let it idle. There was a lot of oil on the wire side of the old sensor so I'm assuming it was cracked. Anyway it's fixed for the time being anyway.
  • ehuffehuff Member Posts: 4
    I have a 2000 Grand Cherokee with the 4.7 engine and 66,000 miles. Recently, for the first time the "check engine" light came on. The engine code indicated I had a misfire in cylinder 3. The coil and plug for that cylinder checked out O.K., but the compression is less than half that of the other cylinders. However, the remaining cylinders have variations of as high as 25 lbs./in. Mechanic tells me that bad cylinder heads are very common on this engine and that they probably need to be replaced. Has anyone else had such a problem?
  • tuggajbtuggajb Member Posts: 646
    have 2000 grand with 4.7 and have 156000 miles with no trouble have to do wet test on cyl that is low after you add oil and retest if reading goes to normal have bad rings if stays low then have head problems if check engine light came on could be computer prob
    the computer is mounted on the fire wall on right side behind the ac aculumater i had croaked connections there from water off aculumater cleaned greased OK now
  • ehuffehuff Member Posts: 4
    Thanks for the reply. Sounds like the problem is in the head(s). I squirted some oil in cyl. 3 the last time I checked the compression. Compression rose only 5 lb. (from 59 to 64). Question seems to be whether can be solved by valve job or if the heads actually have to be replaced. Obviously the latter is MUCH more expensive. However, I've received no other response so it looks like there is no widespread defect regarding the heads. Can't totally discount the computer problem because the check engine light has been off almost all the time for the last several weeks but there definitely IS low compression in cyl. 3 so it seems unlikely the problem is in the computer.
  • tuggajbtuggajb Member Posts: 646
    I would remove valve cover on that side and make sure that lifter was moving the valves on that cyl. could be lifter bad or cam lobe worn. sure would rule all other posablities out before i remove a head am the type that starts on the easey things first work tword the hard parts
  • ehuffehuff Member Posts: 4
    Makes sense to me. That'll be my next move.
  • lundelllundell Member Posts: 6
    hey i have an 91 jeep cherokee sport and it has a clank sound it the engine i think that it is a rod but i am not sure and i was just wonderen if any one else has had this prob that could help me friend said that it happend to a guy he new and he just drove it then about 30 miles later if busted and he had to get a new engine so i was wonderen if it is some thing worth tryin to fix or should i just put a new engine in it when it dies
  • lundelllundell Member Posts: 6
    well the sound is coming from the top end of the engine and it goes with the rpms and i think that it is just one cylinder the sound is like some one is hitting a hammer on the inside of the engine i know i sound like a dumb [non-permissible content removed] but if anyone can help me out with a answer on how to fix it if they have had prob i would appreciate it.....
  • tuggajbtuggajb Member Posts: 646
    might have broken valve spring not to hard to change that don't even have to remove head

  • tuggajbtuggajb Member Posts: 646
    if from top end probly not rod
    remove valve cover and look see if broke valve spring
    what engine you have 4.0
  • lundelllundell Member Posts: 6
    yeah it is a 4.0 straight six h.o.
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