I just bought a 2000 sport 4x4 with the 4.0/automatic combo, it's got 150k miles and has spent it's whole life in Phoenix AZ. The rig is completely stock and runs, rides, looks and drives fantastic. But here's the thing, no service records came with it. I plan on keeping it for a long time so I want to go through it and do the proper maintenance for the age/mileage. So beyond an oil change and filter, air filter, plugs and wires what should I do? I'm completely new to Jeeps and the XJ line, what services need to be performed? Thx in advance =)

 

The hot weather is just around the corner so in addition to the maintenance u mentioned, I'd suggest a complete cooling system overhaul/replacement. All the parts, including a new rad, about $250, u doing the labor and in an afternoon. With the old rad out, it's really easy to replace the water pump, t-stat and housing, the fan clutch, etc. The XJ rad is kinda dinky so the entire cooling system needs to be top notch condition in the summer/hot months.

Don't forget the other fluids.....tranny, diffs, t-case, etc.

I'd make one other suggestion for anyone with a DD that's no longer covered by factory warranty.....raise the hood 2-3 times each week, take a look, check things/fluids, etc., only takes 1-2 minutes.

 

^^^ x2. Could not agree more

 

X2! a cooling overhaul was the first thing i did when i got my 2001 and i will suggest the samething to you.. later model jeep have very tedious cooling sys. it must run at a 100% or you run the risk of your head cracking..

and by doing the maintenance you have mentioned ( and everyone elst ) your jeep should last long time

 

I have a question about changing the fluids... I do not recall where I heard this but I have heard that if you have not changed the fluid in the transmission and/or diffs than changing it may actually be worse? Can this be true in some cases?

 

if you change the fluid in your tranny it can cause leaks i know that my jeep 99 takes synthetic oil in the tranny and if you have not changed the oil for a long time it will get thick and worn out so if you use synthetic it will find any and every hole to leak out of. that may be what you heard but if your going to change the oil the trans or any gear box you should take the covers of and replace all gaskets and if they have a filter that too.

 

my jeep came with no service records aswell. 225k miles when i bought it.

i did the standard tune up and changed everything liquid in it. even the ps fluid and brake fluid. don't forget those 2.

also ended up changing thermostat and water pump after the pump went out about 5k after buying the jeep.

on the tranny subject- when i got mine the fluid was in need of being changed, but it didnt look too bad. it was still fairly red. all i did was pulled the plug and drained out the 3.5 or so quarts that came out of the pan. then for the next 3 weeks i drained and refilled every week. now i plan to drain the trans with every oil change. my fluid does not look brand new, but it is deffinatly a nice red color and shifts great. been using castrol ATF+4 and no leaks to speak of.

 

Probably more myth than anything......not changing old fluids just doesn't make sense to me , so we changed 'em all, including the power steering fluid and brake fluid. A new filter for the auto tranny comes with a new pan gasket.....filter and gasket about $30, diff cover gasket about $5.

 

Okay, I thought it was a bit odd, but you guys have some pretty good answers. When the weather gets nicer I plan on doing a lot to my xj. I'm not much of a mechanic, just a college kid with my dad's tool bench. From the sounds of it I can do most of fluid changing myself, is the differential something I can do myself? Never heard of changing that fluid.

 

Awesome! Thx for the input guys! I LOVE this board

 

X's 3! Good bit of info right there.
And being that your 2000 possibly has the 0331 head keeping it cooled is a very very important element to your engine making it another 150k

 

I've never heard of any fluid that DID NOT need to be changed.....not on the XJ anyhow.

On diff covers, loosen all the bolts and leave top 2 bolts in, carefully pry bottom of cover away from the case (don't scratch/dent/bend cover or case). After gear oil has drained, remove cover, wipe as much old oil out as possible. Cover/case mating surfaces must be sterile clean. Apply thin RTV film to case, gasket to case, thin RTV film to cover, install cover and re-fill with new gear oil.

 

With a 2000, you don't have plug wires as you have the coil pack distributorless ignition. The NGK spark plugs is a very good choice for that ignition system. Ensure gap is .035

Fluids, fluids, fluids. They are the lifeblood of your vehicle. Change all of them, with no exception. Not only does this make sense for a new-to-you vehicle, it also establishes a baseline for future maintenance.

And about that 0331 head. An overheat almost guarantees cracking between cylinders 3-4, where there is a casting defect. So cooling system maintenance is extremely critical. Tolerate no leaks, replace 11 year old hoses and old radiator caps. A fresh 195 degree thermostat (Jeep or Stant SuperStat) is a good idea, as there is no way of knowing how old the stat is in there. So get a new one in there.

And keep a very close eye on the coolant reservoir every time you look under the hood, because the #1 symptom of a cracked 0331 cylinder head is "unexplained coolant loss".

 

Great info guys! I just bought a 99 Sport w/156k and had the same questions.