Good Morning Cherokee Community,


I'm looking for some guidance from people who are familiar with the 2000-2001 Jeep Cherokee XJ's.


Background Context

I purchased a 2000 Jeep Cherokee XJ 4.0L AT in July this year for $500. It currently has 222K miles on it. A fair amount of rocker rust but solid bones. I bought it as my third vehicle in hopes of putting 200-300 miles on it annually to move an old 16ft Glastron boat back and forth from the landing, (Less than 10 miles from my house) and occasionally drive it in the nasty Wisconsin winters. The previous owner had newer shocks, brakes, tires, and basic maintenance records going back almost 100k miles.


Since I purchased it I've changed the Oil (Mobil 1 High Mileage 10W-30 synthetic, which is what the previous owner put in it for 100k miles) and oil filter. Replaced the coolant, replaced the transfer case fluid (Dex/Mercon 3, not 4 thank you other forum thread), 6 new sparkplugs (Champion Double Platinum), replaced the battery, drained the transmission fluid (Not a flush) replaced the trans filter.


Current "Issues"

• When I got underneath the trans pan it was leaking, slightly not bad. As I backed out the 10mm bolts holding it in two on the driver's side were previously stripped and held into place with worksman gasket and the pan was warped. I am going to tap the threads and just replace the pan rather than messing with it further.
  
• The motor has got a "tick" especially when cold and because I know people will ask, yes it gets louder as the RPM's climb. Once it's up to temp the noise is marginally better.I used the old mechanic's trick of putting a nice long wrench on the motor and I'm fairly certain it's not coming from the top end. I will likely pull the valve cover and investigate further. My concern is this, after the oil change I climbed back under it to work on the trans pan and there was a small amount of oil on the bottom of the pan that wasn't coming from the pan gasket and or plug. Any thoughts to common issues, I know the motor has some serious mileage but is there any preventative maintenance that I could do to help that doesn't involve digging into the bottom end?
  
• As I mentioned above, I plan to use the thing to move a "Somewhat light" boat around. I want to change the diff fluids front and back. I've read conflicting threads on what to use for fluid and wanted to see what I should check while I have the covers off? Any recommendations would be super helpful!
  
• Lastly, related to the motor lets talk OIL PRESSURE! When the thing is cold and the "tick" is more noticeable the oil pressure gauge sits somewhere between 50-60. As the Jeep warms up it maintains that nicely when moving, however when stopped at idle it drops roughly to 30 and will occasionally dip right around 20.(Only time it did this was when I drove it home from 3 hours away, normally sits around 30). From other threads, would you suspect that's the sending unit or is that a sign of something that might point me towards solving the "tick" issue? Again any feedback would be massively appreciated
  
• I'd love to hear any recommendations of "things" I should check to keep this ol'POS running for a little while longer. If I can get another year or two out of it putting minimal miles on it annually I'd be thrilled. Happy to post pictures if needed or give any additional information. I'm by no means familiar with the XJ platform but I have plenty of mechanical experience to work on it. If there are solid recommendations for preventative maintenance I would love to hear them. I've got about $1000 in the thing and if I get a couple more years out of it, well, a man couldn't ask for much more!
  

Glad to be apart of the forum please don't hesitate to ask further questions, I'll respond promptly!


All the best,

The Clueless Jeep XJ

 

Definitely change the diff fluids if you are towing stuff. For typical driving the 75w90 (or 80w90) gear oil is suggested, but if you are towing, the 75w140 is the suggested rear diff oil.

You're oil pressure sounds great. It's supposed to be higher when cold and come down when warm. Anything above 13psi at hot idle is within spec for the 4.0L. Typically you want to see it get up to around the middle of the gauge when the RPMs go up and the engine is hot.

For your oil leak -- these engines are known for leaks, search this forum for many many threads on identifying and fixing said oil leaks. Typical culprits are the rear main seal, the valve cover gasket and oil filter adaptor o-rings.

You're doing the right thing by changing the fluids. Next I would make sure your cooling system can withstanding the towing you want to do.

 

Yeah, oil pressure sounds perfect. Min spec is like 13 psi when at "hot idle".

Playbass's advice is sound. Beyond that:

• Check whether the head is original 0331 or replaced. The 00-01 had a nasty casting defect that if the head is orig you'll want to keep an eye on. The oil leak fixing should start from the top down.. valve cover gasket, adapter o-rings first... only then should you consider tearing into it for a RMS and new pan gasket.
• Check your u-joints - rear and front driveshafts and the axle shafts.
• Clean up all your grounds and cables and make sure you've got clean and tight connections. A lot of electrical wonkiness will result if that stuff is not in good shape. There's a ground in the trunk behind the driver's side trim panel that many folks forget about.
• Get yourself a copy of the FSM. You can find a PDF download at cruiser54.com or xjjeeps.com (lots of other cool documentation resources at these sites as well as the FSM.)

You say that you only want a couple of years and a few hundred or thousands of miles... be warned... once you start really driving the thing you'll find yourself driving it a whole lot more than you anticipated.

 

There are literally zero inherent design flaws of the 4L straight 6. The only issue in it's 20 year manufacturing run was poor head castings for the 00' & 01' model years. Your 00' head has likely been cracked for a long time. You might want to send out an oil sample to Blackstone Laboratories to verify and make sure the motor always has clean oil.

 

Playbass,

Thank you! I heavily appreciate the prompt response. Follow up question for you, I live in Wisconsin, Winter is brutal and I may try to drive the Jeep on the really rough days. Is there any downside to running 75w140 in the rear diff? If I will be using it in the summer to tow and then in the winter to get through the snow, what would you personally recommend? Keep in mind there are three lakes I'll be towing the boat over too, all of which are less than 25 mile round trips.

Thank you again, look forward to hearing your recommendation!

Sincerely,
The Clueless Jeep XJ

 

PatHenry,

Thank you as well for the prompt response!

The head is original, 0331, and has not been replaced. Given it's running still and I only paid $500 for the whole Jeep I will likely not replace it. I did take a look at options for replacement and I'll avoid sticking that amount of money in it unless I need too. I've got a valve cover gasket sitting in the garage which will be next on my list after fixing the trans pan. My suspicion on the oil leak is the rear main seal based on how little is leaking out and where it's leaking out. How much of a pain in the rear is it to replace? Additionally, this is the first I'm hearing of the adapter o-rings, if by chance you could link in a couple of good threads coving these that would be a huge huge help!

I checked the U-Joints, front & rear driveshafts, and they checkout. A little bit of play but nothing I would consider all that problematic. I have not taken a look at the axel shafts, any recommendations on what to look for there?

I'm good on electrical gremlins, one of the first things I did was clean up and tighten electrical connections when I replaced the battery. I did not know about the ground in the trunk so I will make sure to take a quick look at that and make sure it's tight! Great recommendation and info!

I have a factory service manual that came with the Jeep (Which was a nice perk) I appreciate the link and I downloaded the digital FSM!

I've had friends with XJ's in the past and I do love driving them only thing is I love my other two vehicles. I daily drive a newer Inifiniti Q50S throughout the year and the weekend toy is a 50k mile 93 Acura NSX (Childhood dream car). I'm sure I'll try to drive the Jeep more in the winter months if the weather is bad but we'll have to see about another 100k miles !

Thanks again for the response!
The Clueless Jeep XJ

 

I wouldn't expect there to be any problems with running 75w140 in it during the winter. I know some people on this forum run that weight in their daily drivers. FWIW, I believe the XJ manual says to run 75w140 if you doing any towing whatsoever, so that's where I'm getting that info.

 

Here is a thread about replacing the oil filter adaptor o-rings: https://www.cherokeeforum.com/f2/cha...r-seal-252816/

Some people just remove the OFA completely.

 

Playbass,

Thank you for the assistance! It helps me a bunch!

All the best,
The Clueless Jeep XJ

 

You can get a TUPY 0331 head from a newer grand cherokee . A TUPY 0331 head is a better head that doesn't crack like the head that came on 2000 . You should check to see if someone has changed it already .

 

Use a strong flashlight and look down the oil filler hole in the valve cover and you should see this picture if it's a TUPY head. They came installed on 02 and after model 4.0s. Junkyard WJs are a good place to look for them. They usually cost around $50 near me. Watch for the coolant level dropping considerably every few days. That's a good indication a 0331 head is cracked. Mine started making lots of steam out the tailpipe, but never got into the oil.

The second picture shows all the wiring behind the spare tire holder. The other side basically only has the wiring for the passenger's tail light.

One other thing, the valve cover can leak down the back of the head and never show on top. Oil then runs to the lowest spot which is the RMS area.

 

Your oil leak could be rear main. As for the Mobil 1 (and this is just from my own personal experience and I am not a salesman or anything) I used it for many, many years in my Cherokee. I always noticed I had a louder ticking while running it. I switched over to Castrol edge 10w-30 synth and noticed it quieted down a lot. A lot of guys run thicker oil too I think that’s designed more for Diesel engines. Something to maybe try out for you next oil change.

 

I'm still trying to figure out why the OP calls a $500 XJ a POS that seems to run and drive well and has typical issues of any 200k+ mile vehicle.

 

Huge thanks to everyone who has weighed in on this!

Here's An Update

I've got the trans pan back on after tapping the two threads that were stripped out, new gasket, trans filter, and fluids topped. Additionally, I've got the rear-diff fluids changed out with 75W145, as I will be hopefully towing with the vehicle. I checked out the grounds in the rear and have everything nice and tight. I've put roughly 150 miles on the Jeep since doing this and it appears to be running with minimal issue.

Next On The To Do List

• I've got a replacement valve cover gasket, and I plan to get that changed out and inspect what Dave1123 pointed out below.
• I plan to pull apart the aftermarket head unit that the previous owner put in. I'm guessing the remote wire (or potentially all of the wires) were not properly wired. I suspect this because if I turn on the stereo when the Jeep's running and then turn off the Jeep it proceeds to come back on moments later. Likely a bad remote connection. I've done 100s of these as I used to work at an audio shop in high school
• I may try Thunder Thighs suggestion when I change the oil next and use Castrol. The tick is certainly noticeable when the Jeep's cold and until I get up over 35-40 mph you can hear it clearly. I'm sure it's still ticking at those speeds but I just can't hear it. (I'd be open to any additional suggestions for getting this to "Cheaply" quiet down)

Outside of that I can't complain, it's not overheating, oil pressure is staying where it needs to be and I hope to drive it as the winter comes. I'd like to thank everyone again that weighed in on this, it's a huge help and I'm always open to hearing other problem areas that I should check out!

Thanks again,

The Clueless Jeep XJ

 

Good Morning,

So I've put over 1500 miles on the Jeep over the past few months and things appear to be running good outside of a few minor "issues."

I could use some help diagnosing this and I'm more than open to any suggestions. I walk down and start the Jeep before I drive it in the mornings, often letting it warm up for 5-10 minutes before driving. The only odd thing that happens and has started to get more noticeable is that the idle fluctuates when the heater is running and the Jeep is sitting. Yes, even when driving. It's not much, just a couple hundred RPM at idle jumping from 600-700 to 800-900 RPM for 15 seconds or so and then drops back down. Any ideas about what that could be?

Additionally, the tick is getting louder I replaced the valve cover gasket about 250 miles ago, while I had it apart I checked all of the rockers, springs, and rods to make sure nothing was out of place. The noise must be coming from somewhere else. Any idea about this? That doesn't involve taking the bottom end apart?

Any feedback would be much appreciated!

Thank you,
The Clueless Jeep XJ