Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Jeep Cherokee Grand Cherokee Engine and Performance Problems



  • 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.

  • 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.
  • 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 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.
  • 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.
  • 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.
  • 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 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
  • 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 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 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 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 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 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 Posts: 4
    Makes sense to me. That'll be my next move.
  • 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
  • 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 Posts: 646
    might have broken valve spring not to hard to change that don't even have to remove head

  • tuggajbtuggajb 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
  • yeah it is a 4.0 straight six h.o.
Sign In or Register to comment.