Your Guide to "EXTREMELY common problems with an XJ (and how to fix them)" - Jeep Cherokee Forum (2023)

I'm sure this thread will sink into the depths soon enough, but I want to at least try to do something to cure the problem of repeatedly asked questions. Yes, I know that would require people reading the thread, but I think I've titled it clearly enough for anyone who comes to these forums to think "hmm, I should read that thread! Might be useful info in it!"

Please help me collect symptoms, causes, and solutions so we can HOPEFULLY make a solid database of these issues.

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Symptom: Thumping or thud noise when taking off from a stop

Description: "When I take off from a stop, my drivetrain makes a 'thump' or feels like a bowling ball rolled into the lift gate".

Cause: The slip yoke requires grease, and is sticking, causing the "thump" when taking off from a stop.

Fix: Unclasp the rubber boot over the slip yoke and slide it out of the way, then slather some axle grease all over the slip yoke. Work it into the splines really good. Put the rubber boot back and reattach the clasp. The clunking should go away immediately on the next drive.

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Symptom: Only the driver's door window switches seem to work

Description: All windows operate fine, but ONLY through the switch on the driver's door, and pressing the window lock out switch has no effect.

Cause: The "Window Lock-Out" switch has shorted out. This is usually due to a broken wire, but can sometimes be related to the switch itself.

Fix: Take off the door panel and the interior trim to the left of the pedals. Follow the wires from the window switch to where they pass through the door and into the cab of the vehicle. Look for breaks in the wires - this is extremely common. You can either
A) Repair/replace the wire, or
B) Jumper the wire connector with a paper clip or other U-shaped piece of metal, to connect the two wires together. Search for "Window Lock Bypass" on the forums for a guide.

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Symptom: One or more of my power windows only roll down/up or do not work at all.

Description: Sometimes a window will only roll down and not up, or up and not down, or not work at all.

Cause: If the window does not move at all, it's most likely the window regulator that has failed. If the window rolls up but not down or vise-versa, it's more likely a broke wire.

While each door has it's own window control, the master switch on the driver's door still has main control and overrides the rest of them. So if the wire leading from that switch through the driver's door is broken (again, extremely common), it will cause issues with the related window.

To test this, remove the door panel on the affected door. Look for the wires that lead from the window switch on that door to the window motor - there is a connector somewhere in the middle of it.

Disconnect that connector, and take two pieces of wire, the ends of each stripped. Make an X shape with those two pieces of wire, and insert the ends into the connectors, essentially CROSSING the wires.

If the window now moves in the OPPOSITE direction of how it moved before (i.e. it rolled down but not up, NOW it rolls up but not down), then the window regulator is fine, and it's DEFINITELY a broken wire.

Fix: Find and repair the broken wire, or replace window regulator if it ends up being back.

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Symptom: My Jeep won't start in park/will only start in neutral/won't start unless I wiggle the shifter!

Description: You turn the key and nothing happens. Or it tries to crank for a split second, then stops immediately. You think to yourself "dead battery", but the battery turns out to be fine. You bump the shifter/put it in neutral, and the next time you turn the key, it starts just like normal.

Cause: The Neutral Safety Switch is likely dirty/corroded. The NSS prevents the starter from engaging when the shifter is in any position other than Park or Neutral, but they often get dirty and corroded, which causes the contacts in the switch to not read which position the shifter is in, therefore not allowing the starter to engage.

Fix: Remove the NSS and replace it with a new one, OR go the much, much cheaper route and take it apart to clean it. Search for "neutral safety switch cleaning" to find a guide on this.

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Symptom: There is an INCREDIBLE squeaking coming from the cargo/back seat area and I can't figure it out!

Description: When going over bumps, uneven terrain, or even just from the vibration of the motor running, sometimes you hear a very high pitched and extremely annoying squeaking.

Cause: Two main things usually cause this: the latches for the upper section of the rear seat, and the lift gate latch.

Fix: Grease. Lube up the seat latches pretty good, lube up the lift gate latch pretty good. Passengers won't have to worry about getting grease on them as they would only be back there when the seat is latched anyway.

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Symptom: One or both of my door speakers do not work!

Description: My stereo works fine, but no sound is coming from one or both of my door speakers.

Cause: Broken wire leading to the speaker. As you've already seen twice in this thread, broken wires in the door jambs are VERY common and usually the #1 source of electrical issues in XJ's. The constant opening and closing of the doors bends the wires back and forth, and Chrysler used really cheap grade wires, so eventually they break apart.

Fix: Find and repair the break in the wire, or run a new section of wire through the door.

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(Contributed by Salad)
Symptom: One or more of: Poor gas mileage, hissing/gurgling sound when under acceleration, raw exhaust or fuel smell from the vehicle

Description: "A month ago my mileage started getting worse but I drive a flying box so I didn't care too much, but now when I put my foot down I hear a watery noise and a hissing. Last night in the drive through I smelled gas while I was sitting still!"

Cause: The factory exhaust manifold is prone to cracking where the collector pipes merge to meet the flange for the downpipe to the first O2 sensor. This causes a leak of raw exhaust and intake of fresh air, fooling the computer into dumping more gas in.

Fix: The exhaust manifold should be welded (which may not last long) or replaced (recommended). This requires removal of the power steering pump, air box, and intake manifold. This may be a good time to upgrade to an aftermarket exhaust header which can provide for greater operating efficiency over stock, as well many are designed to resist cracking.

These writeups can be used as guides:
http://www.jeepingsingles.net/tech/manifold.asp
http://www.jeepforum.com/forum/f12/4...-quide-279496/

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Symptom: Engine idles poorly or is hard to start when hot, but clears up after a few minutes and acts completely normal.

Description: "It's 90 degrees outside and I just got off the highway to get gas. I got to talking with someone else about XJ's and when I got back in mine 10 minutes or so later, it wouldn't start/it started and idled VERY poorly, like it was missing on a couple cylinders. After a few minutes it started and ran like normal."

Cause: The later year 4.0 engines tend to have this problem a lot. Due to the design of the exhaust and intake manifolds, the fuel injectors can get very, very hot, and the fuel inside them will boil and turn to vapor. This often happens after a long(ish) drive on a hot day. You park your Jeep at the store, and with the engine off, there is no air flow to keep things cool. The under-hood temp climbs, and the hot spots tend to be the fuel injectors for whatever reason - specifically, Injector #3 gets the worst of it. Then when you get back in about 10 minutes later, when the temperature has risen as high as it's going to get, you get the rough idle/no start symptoms. Eventually the vaporized fuel will be pushed through the injectors and fresh fuel will be injected, and the engine will run like normal.

Another possible factor that contributes to this issue is when the plastic housing of the injectors has cracked, exposing the metal inside of the injector directly to the heat. If your injectors are old, the plastic has likely cracked, and they are not more susceptible to heat. Replacing the old injectors with new/upgraded ones will HELP with this issue, but not solve it entirely.

Fix: Chrysler released two Technical Service Bulletins on this issue. One suggests a reprogramming of the ECU to engage the electric fan at lower temperatures in an effort to keep the under-hood temp down, but this generally proves to be ineffective as the problem occurs with an engine-off heat soak.

The other TSB recommends the installation of "heat sleeves", little pieces of fire proof shielding that slip around each of the injectors. The part can be ordered through any Chrysler dealership, or you can use basically any type of heat shielding to deflect heat away from the fuel injectors.

Other ways of relieving the heat under the hood are:
-Installing hood vents
-Leaving the hood open after a long drive on a hot day (not recommended unless you aren't afraid of theft/vandalism)
-Installing a timer for your E-fan that will let it run for several minutes after the engine shuts down, or adding an ambient air temperature sensor that will run the fan until that temperature has decreased (might cause problems)
-Replacing the exhaust manifold with a header as steel cools faster than cast iron
-Turning the A/C off a few minutes before you reach your destination to take a load off of the engine

Let's keep this going!