Jeep Cherokee Grand Cherokee Engine and Performance Problems



  • mike2fredmike2fred Member Posts: 1
    I have an ongoing ignition issue no spark in 1 and 6 I replaced the coil pack and the pcm I had the pcm flashed at the dealer and checked the cam posistion sensor and crank posistion sensor omhed all wires and injector pulse is good .Any Ideas?
  • eagle18411eagle18411 Member Posts: 1
    I have a 2001 Jeep Grand Cherokee Limited (4.7) with 75000 miles on it. Anytime I accelerate over 10 miles an hour a high pitch squeak strats. Multiple letting the air o0ut of a balloon slowly by ten and thats what it sounds like. Sounds alot like a belt but it only does it over 10mph and all the belts are good. I took the tire and brakes off lifted it up and ran it off the ground. The noise was still there. I got close enough to narrow the noise down to the front axle on the passenger side. I have had no mechanically problems with this vehicle at all. Any suggestions what this could be?
  • brian69brian69 Member Posts: 1
  • 99limited99limited Member Posts: 5
    I'am sure most of you have heard this before. I have a 1999 Grand Cherokee V-8 that has plenty of power but rotten gas mileage. With the cost of gas I'am willing to sacrifice some power to get better fuel economy. Has any one had any success with any of the chips that are available and does a non restrictive air filter help
  • agallmanagallman Member Posts: 6
    I have a 2001 Grand Cherokee Laredo and started hearing a very high-pitched sound that occurs when I decel (let off the gas) at speeds above 15 mph. When I press the gas pedal and accelerate, it disappears. It also disappears when I slow down below 10-15 mph or when sitting idle. It's not metal against metal (such as rotors/brakes) or anything like that. Sounds like a really 10x steam kettle.
    Any suggestions?
  • fedup11fedup11 Member Posts: 1
    I have been checking out this forum and can find several people that are having similar problems with their jeep but not quite the same as us. We have a 97 Grand Cherokee Lerado, the problem we have is this. Each day when you first get in it you can drive normal for about 2-3 miles. Then all of a sudden the rpm's will go up and down, the motor acts like it wants to shut off. It runs like crap for about 1/2 -1 mile at a very slow speed. Once you get past this you are fine for the rest of the day, it won't happen again and the jeep runs great.....until the next day. We started by replacing the crank position sensor, followed that with the front oxigen sensor, replaced the plugs & wires, replaced the coolant sensor and finally replaced the pickup coil sensor in the distributer (along with caps and rotors). We even removed the cables from the battery for a time thinking that maybe that would re-set the computer memory somehow. It's still doing it! We thought it might be temperature related since it just happens the first time you get in it for the day, but why (if it's freezing out) would it not do it after it sat for 8 hours during a normal days work? The engine has to be cold then too. We are totally confused as to why this happens only once a day.
    On another note: we do have problems with out auto-on lights, they flicker as you go down the road. If we turn it to manual position we can override that but then the light on the light switch itself will still go on and off. We're thinking we just need to replace the switch for that, is that right? The two couldn't be related, could they? Any suggestions?
  • xscoutxscout Member Posts: 141
    I can't say my problem with my 1997 Grand Cherokee was exactly like yours, but it was similar. Car would start OK in the morning and then later as I was driving down the road it would start to run like you describe. In between episodes, car would run perfect. This would usually occur most every day but not always. Sometimes it would do this for short periods on and off all the way to work and sometimes it would just get stuck in this mode for most of the trip. I was always able to restart it if it shut down, usually with ease, sometimes not. And it could occur more than once in the day. I ended up replacing the PCM after doing the position sensor route to no avail. Check your connections on Your PCM to make sure they are clean and tight. If you do have to do the PCM, it will run you about $250 for a rebuilt with warranty if you do the switch out yourself. Make sure it is pre-programed, they may need your VIN# when you order it. It is a very easy job.
  • 5213252132 Member Posts: 62
    I got the same problem (and the same Jeep), well, I wouldn't call it a problem since it did it when it was new. It sounds like the front differential is making that sound. Do you have 4WD?
  • turbanskiturbanski Member Posts: 85
    Has anyone seen performance comparisons between the new for 2008 4.7 V8 and the Hemi option? The 4.7 V8 for 2008 is a completely new design rated at 305 HP vs the Hemi's 335HP. The engines torque ratings are not that far apart either. I have a new JGC with the 4.7. It is not broken in yet and it is very quick, quiet and smooth. I have to be careful in local traffic when taking off from a traffic light I quickly find myself at 40+ MPH with very little effort. It would be interesting to see a performance comparison. Thanks.
  • aguarinoaguarino Member Posts: 13
    I need to find the location of the oil pressure sensor on a 2000 Jeep Grang Cherokee. I have a high (4.0) reading with the ignition on. I turn off the ignition and it will drop to 0. Upon turning the ignition on (without the motor started) it will jump to 80 pp. What is going on???? Where is the sensor located??
  • tuggajbtuggajb Member Posts: 646
    mounted right above oil filter
  • skateaskatea Member Posts: 1

    I have a grand cherokee 1998, 4.0 L. When I am driving the engine shuts down and I just restart and it does ok for a while. The Dealer changed the distributor cap and roter, cleaned the injectors and throttle body and it is still the same if I drive and the RPM goes above 2000 for awhile, the engine shuts off and it starts again but why does it do that? Please help.
  • jeepnjohnjeepnjohn Member Posts: 2
    My first post here.

    My 98 Cherokee has developed a problem when running along not under load (flat open highway) it will miss sputter off and on. This does not seem to be affected by temp and is intermittant. Gas mileage has been affected as well. It has just rolled over 100K mi's and has had no other issues.

    Thanks, John
  • andrea6928andrea6928 Member Posts: 1

    I drive a 2001 Jeep Cherokee, automatic transmission, 4.0L. My check engine light has been coming on and off for the past year. In all instances except the very first, the light came on while idling.

    January 2007: Light comes on upon starting the car. Code read catalyst efficiency below threshold. Cat was clean, so I replaced the O2 sensors.
    9/24/2007: I had a vacuum leak repaired and the light was turned off.
    10/4/2007: The mechanic adjusted "something" for no charge, and the light went off.
    11/21/2007: Light came on, but I went out of town and didn't have it serviced until 12/1/2007. Code read catalyst efficiency below threshold. My O2 sensors and cat looked fine, so the mechanic didn't think I needed to replace them. Mechanic turned light off.
    12/9/2007: Light came on, but I didn't have a chance to bring it in. It was off upon starting the car on 12/12/2007.
    12/14/2007: Light came on, but was off upon starting the car on 12/18/2007. That same day, while idling, it came on again and was on until about 12/28.
    1/18/2007: Light comes on again, and has been on since then, except for a brief 10 minute period between the time I started my car this morning, and when I idled at a traffic light.

    Does ANYONE have any idea what's going on? I've been to the mechanic more times than I can care to count. The code always reads catalyst inefficiency, but my sensors and cat are all clean.

    Thanks so much for any insight you can give.
  • jeepnjohnjeepnjohn Member Posts: 2
    I'm glad you found the problem that has been ailing by heep for a few months now. Question- Where is the upstream o2 sensor?
  • mtrhead73mtrhead73 Member Posts: 1
    We just bought an 08' GC 3.0 diesel, only has about 400km on it. I am noticing that at highway speeds of 110km/h (about 70 mph) the engine is at 2500 rpm. This seems too high, we are in "D", don't have tow/haul on, it almost seems like it hasn't kicked in to overdrive. Even after an hour drive same thing. The temp is -10C, so it's not too cold.
    This is our first GC, not sure if this is normal or not.
    Can anyone help us out, is something wrong???
  • turbanskiturbanski Member Posts: 85
    There's not too many diesels out there. They don't even sell them in New York State probably due to emission standards. If it is of any help to you my 08 JGC with the 4.7 V8 indicates approximately 2,000 RPM @ 70 MPH.
  • jim203jim203 Member Posts: 1
    Can anyone help. I replaced the waterpump on my jeep and when I went to start it, I heard a grinding noise when I turned on the ignition. It sounded like the fan blade had hit the plastic cowl. I immediately checked back under the hood and everything looked fine. I tried turning it over again and didn't hear the grinding noise, but the car wouldn't start. By reading numerous blogs and forums I attempted to find the problem. I checked the coil wire and I am not getting spark. I tried the tricks with the alarm system, no luck. I ran a diagnostic check reading the blinking lights and got a 54 which showed crank position sensor. I had it towed to a mechanic and he changed the cps which didn't help. Now he wants to try changing the crank position sensor to the tune of $300, with no guarantee of it fixing the problem. Could I have done something in the changing of the water pump to cause this. Thanks for your help.
  • leo01leo01 Member Posts: 3
    I have a 2000 grand cherokee and the radiator fan won't stop running even when the car is off. replaced relay , temp sensor and thermostat. Any ideas
  • xscoutxscout Member Posts: 141
    How long does it run? It is designed to run by temperature, not by wether the car is running or not. It is normal for it to run for a short while after the car is turned off. Of course if it is draining your battery that a defect.
  • chevergecheverge Member Posts: 1
    hello, I have a 2001 jeep grand Cherokee limited wheel drive with a 4.7. I recently had a bent exhaust valve in #7 cylinder. The guide to one of the secondary chains broke and i jumped time. I took it apart, had a valve job done to that head , then put it back together with a new gasket kit. I also put new plugs in it. It runs like crap, like its running on 7 cylinders. I did a compression test and all 4 cylinders on that side have close to 150. the check engine light is on sometimes bu not much and when i took it to auto zone to get the code it came up bad O2 sensor on #1 Bank and that it was running lean. I'm not sure which bank is the #1. It wont idle on its own hardly ever, and lacks power tremendously. I checked the coil packs by unbolting them, putting a plug in them and holding them by the valve cover to see if it arcs, and they all are. It seems to be running very rich now, as it smokes a little black smoke sometimes. I think it is a fuel or fire problem, but not sure where to begin. Could the O2 sensor make it run that bad? Thanks Dave
  • thedlydrvrthedlydrvr Member Posts: 5
    i have a 94 jeep cherokee sport that is overheating at idle. it has a new thermostat, flushed cooling system, new hoses. The pressure was tested and its good. however the jeep has 2 fans. one is connected to the pully and one is electric for the A/C. When i have the ac on it doesnt overheat as quickly. does anyone know what could be wrong with it. it runs great considering it has 175K.
  • dixiecrawlerdixiecrawler Member Posts: 89
    The electric fan isn't just for the A/C, and it sounds as if the electric fan isn't working at all. It is run by a coolant temp. sensor which, of course, turns it on at a specific temp. While idling, listen for it to come on, especially once the engine is warmed up. If it never comes on, that sensor would be the first thing to check. If the sensor isn't the problem, it has to be the fan itself.
  • onedoublelonedoublel Member Posts: 2
    My 2000 JGC will blow hot air from the AC after driving for over 45 minutes or so. Usually after stopping and the engine cools, when I start up again the AC will blow cold then after a while start to blow hot again. Any ideas?
  • tuggajbtuggajb Member Posts: 646
    poss the thermo clutch on the engine fan has gone bad when cold fan dosn't turn as fast when hot fan turns faster to chack run engine to temp sut off take hand and turn fan should be hard to turn if not change clutch
  • tuggajbtuggajb Member Posts: 646
    sounds as if ac coil is frezzing up pos low on ac fluid have them check that
  • billo7billo7 Member Posts: 1
    i have a grand cherekee .

    the thign is vibrating at 70 miles per hour.

    anyone know what may it may be

    thnaks :sick:
  • thedlydrvrthedlydrvr Member Posts: 5
    where is the sensor? I will have it changed out if thats the case.
  • thedlydrvrthedlydrvr Member Posts: 5
    can you educate me about the fans? Mine has two. The main fan connected to the belt! is that suppose to engage? Mine isnt. its at one speed. I noticed that my dads toyota fan engages when you first start it. Is mine suppose to do that. also my electric fan engages only when the a/c pump is on.(defrost or A/C) How do i find which one is screwed up and where are these sensors at?
  • dixiecrawlerdixiecrawler Member Posts: 89
    Sounds like you're low on freon. Have it checked.
  • dixiecrawlerdixiecrawler Member Posts: 89
    Sounds like your fan clutch may be bad. The main fan (mechanical, belt driven) should be turning whenever the engine is running. Replace that and let me know if that solves your problem and if you have any more questions.
  • thedlydrvrthedlydrvr Member Posts: 5
    today i let the jeep warm up to the point of over heating. (please note that the fan is spinning when the engine is on.) then i turned off the engine and checked the fans resistance. its has very little resistance. i dont think thats normal. Its a temperature based fan, If its cold it should spin freely. if its hot it should have resistance. AM I RIGHT? If so i will replace the clutch fan.
  • tuggajbtuggajb Member Posts: 646
    your right!!!!!!!!!
  • dixiecrawlerdixiecrawler Member Posts: 89
    It could be caused by several things, but the most common problem would be tire balance and alignment. If it's been a while since you've had this done, rotate and balance your tires and have the frontend aligned. Before you do this, make sure that your tires aren't just worn slap out and need to be replaced. If you have good tires on your truck, the earlier mentioned service might take care of your problem. Let me know if this helps.
  • thedlydrvrthedlydrvr Member Posts: 5
    ok. im still overheating. flushed radiator, new thermostat, new fan clutch, new electric fan sensor switch. anyone have any ideas? tell me how it could be the water pump. does anyone know how to check the pumps pressure?

    This is whats happening. It warms up. if its at idle it will gradually overheat. when i drive the temp will suddenly drop below 210 at normal operating tempature. whats going on?
  • colemankcolemank Member Posts: 1
    I don't have a GC but have had similar issues with a Cherokee , Dakota and Ram PU . It was the Goodyear tires. They just wouldn't ballance. On all I switched to Michelin and the problem was gone. I won't get a vehicle with Goodyears ever again. I am currently looking at a GC Diesel and the dealer is going to switch the tires before I even pick it up. Just a thought.
  • leo01leo01 Member Posts: 3
    Thanks found the problem a bought a relay from auto zone that was bad took it back and bought one from the dealer. It's been three weeks and it works fine.
  • leo01leo01 Member Posts: 3
    I have a 2005 jeep grand cherokee and must of the ac and heater control panel is dark. I took it out but everything is enclosed in the panel, can I open it or the panel has to be replaced.thanks for the help
  • vdragonflyvdragonfly Member Posts: 3
    Ok I need your help guys, (my husband is no help at all) I have a 94 Jeep Grand Cherokee 6 cylinder. The problem is the jeep won't start plain and simple right? No, the jeep started by taking longer and longer for the fuel pump to kick in, 5 seconds, 15 seconds, 5 minutes, 10 minutes, then nothing. Had a diagno0stic run and we didn't get any error codes, so we replaced the crank shaft position sensor and it started and ran fine for one whole week, then back to the no start buisness, fuel pump is not kicking in...has to be the fuel pump right? $350 later we have a new fuel pump installed and still no start, no pump kicking in, Now I have a jeep in my garage that doesn't move and still no idea what the problem is, IT"S IN GREAT SHAPE!! I would hat eto have to junk it because we can't figure out what's wrong..PLEASE help me :mad:
  • kcfsjeepinkcfsjeepin Member Posts: 1
    Well I'm an 18 year old girl who knows NOTHING about cars. I have a '99 Jeep Cheeroke Sport that "chugs" on me ocassionally, sometimes stalls entirely. It usually "chugs" within the first few minutes; so before it warms up. It back fires through the intake, sometimes it helps to pump the gas pedal. I have replaced the coil, throttle position sensor, and the mass air flow sensor, and it continues to "chug." I've taken it to a dealer who was utterly clueless about the issue. Dealer wanted to replace all "primary ignition components," but would not guarentee that this would solve the problem and this would be at my expense. When I told them this was unacceptable, they told me to wait until it gets worse i.e. causes an accident!! By the way, this was a FIVE STAR dealer in METRO-DETROIT. Can anyone help? I'm just about on walk mode and cannot be seen in a mini-van :)
  • tidestertidester Member Posts: 10,059
    There are a lot of possible causes for those problems. How about starting with something really simple - like trying a tankful or two of gasoline from another gas station? This is basically a shot in the dark but I'm wondering whether winter blended gasoline may be affecting your engine's performance. Let us know what happens if you decide to try!

    tidester, host
    SUVs and Smart Shopper
  • 5213252132 Member Posts: 62
    I personally don't think it has something to do with the ignition system. We had a 1998 Ford Windstar that did the same thing. It turned out that it was the fuel pump. How many miles does the Jeep have? The normal mileage for a fuel pump is about 200,000 miles. By the way, the price to replace the fuel pump is $400.00 :cry: . That's the reason we traded it in for a 2001 Grand Cherokee.
  • sswsmksswsmk Member Posts: 1
    I have a 99 cherokee classic with a 4.0 and it is having some problems. It does not do it all the time but it sputters and misses really bad. sometimes it just idles really rough. It has only died once and i barely got it to start back. Its throwing about four codes saying O2 sensor too lean and rich, bank one and two. Someone said it was the O2 sensors for sure, but i didnt think that they went out that easily. I also thought it could be a vacuum line, so i checked and didnt find anything wrong, missing line, broke line, etc. Can anyone please help?
  • viper_25_usviper_25_us Member Posts: 1
    first thing that comes to mind is a faulty sensor....but my jeep also did the same thing(91 cherokee sport) i tried everything and still no fix.then i bought a brand new radatior and the problem was gone and never had it sence 4 years strong and running great
  • guertinguertin Member Posts: 39
    Hi everyone.
    I'm new to this forum (I'm most active in the GC SRT8). So, please forgive me if I don't fully understand the general Grand Cherokee. $400 for a fuel pump? I just installed one in my 1979 Olds for $35! It took me about an hour (mostly to clean the gasket area). Perhaps the Jeep is much more difficult to put in?
  • rochon230rochon230 Member Posts: 3
    I have 2000 JGC with a V8 and 122K miles on it. When you put the jeep in park, and even driving down the road, the engine surges up and down. We have taken this to two repair shops with no relief. Does anyone know what this problem is, and is this a dealer only repair?
  • tuggajbtuggajb Member Posts: 646
    have you changed the tps yet?
  • rochon230rochon230 Member Posts: 3
    What is the tps?
  • tuggajbtuggajb Member Posts: 646
    throttle position sensor sences how hard toy mash the gas sends info to computer to tell it to inject more gas if bad computer sends surges to injectors looking for where throttle is at
  • rochon230rochon230 Member Posts: 3
    O.K., I am with you so far. Is this something a mechanic can fix, or is this a Jeep dealer only fix. Is this something that is bolt on, or does this need some adjusting?

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