Here are some thoughts:
1) Newish isn't "bestish". As the old Rover V8 line came to an end, worn manufacturing parts really screwed up tolerances. Later model 4.6s (especially) and 4.0s are notorious for slipped liners causing expensive $5k Top-Hat engine replacements. Allegedly, it got so bad that as blocks were tested all of the good 4.6s were set aside for Rangies, while the Disco ones got "marginal". There is plenty of online evidence to backup issues with 2003/4 D2 blocks being nightmares. You almost never hear about slipped liners on earlier D1s and Classics, and early D2s it seems less common (but head gaskets are still an issue.)
2) Records, Records, Records. The headgasket design and cooling system are issues. At this age, it's best to just budget $800 and go through the cooling system. New everything, from fan-clutch to radiator, and all the hoses. BUY THE TD5 (turbo-diesel) Thermostat! It's a 180 T-stat and will help save your block from the dreaded (and sometimes inevitable) liner slip. Buy an ultraguage. The temp guage on the D2 does not work. It only moves AFTER you have a problem. As soon as I plugged mine in, I discovered a bad thermostat sticking which was getting my temps to dangerous levels...without me knowing. Dumped in a TD5 T-stat, and I rarely go above 200F, including 4-wheeling in Moab heat. The heater still works too, so don't worry about that.
3) Proper Oil. This is a flat-tapped motor. 15W40 Rotella Diesel Oil and/or Delo 400 are recommended. The Rotella 5w40 synthetic is expensive but also very good. Notice that the temp. range for 15W40 doesn't go below 32F. If you are in a cold climate, you will need to swap to a 5w30 "SJ" spec (this is an older specification, I've found that Napa non-synthetic to match it) in order to meet the requirements in the owner's manual. Always get the biggest oil filters (they aren't too bad). If you don't believe this can be an issue, look up camshaft and lifter issues on the Rover V8. Remember, the Rover V8 is a Buick V8 from the 60s that Land Rover modified by changing ignition systems and fuel injection over the years. It has an AWESOME torque band for off-roading, but other than that.....it sucks. Like you'd expect from a 50 year old design: Horrible gas mileage, down on power, requires premium fuel, etc. But it is aluminum (weight), and that torque curve is awesome when in 4-lo.
4) CDL. If you intend to Overland, the CDL is an invaluable traction aid. The Center Diff Lock is available on 99s and up to 2000 I believe. All you need is a $300 Ashcroft kit (I did the D1 swap...not recommended, spend double on the cable), a few hours in your garage, and you have the CDL. If you get '01-'03 you will need to spend thousands on a T-case swap. If you get an '04, you'll have the T-case from the factory...........but start budgeting for that $5k top-hat engine replacement instead...
5) Front Drive Shaft. The sealed bearings on the front double Cardon shaft are nice....in theory. In practice, the cats are so close it over-heats the grease and the U-joints dry up and sieze. If not caught in time, they typically fail on the interstate (high speed) and the shaft swings like a club taking the front half of your tranny with it, and possibly denting your floorplan. You need to get it rebuild with serviceable joints INCLUDING THE CENTERING BALL (I know Great Basin Rovers has serviceable parts, that's where I got mine). You'll need a special needle fitting to put grease in the centering ball and then you are on your own to grease the shaft every 5k or so miles. Then you should be fine. Or you can spend more more money on a sealed shaft and just pre-emptivly replace it every 70k miles. Your pick. The stock shaft seems to be good between 70-140k miles. In other words, after 70k you are rolling the dice...
6) Rear flex-disc. Not that critical, but still a semi-pricey part. The rear flex-disc on the driveshaft can develop cracking and eventually fail. If you look under your vehicle often, you should be able to catch this one in time (mine is cracking right now). Just be aware.
7) Check your low-range shifter. Most have never been used and can freeze. They can even break if you are unfortunate and apply too much force. When you put in the CDL makes sure you remove the interlock solenoid. It has a tendency to fail and you are stuck in whatever gear it was in (including neutral), until you tear apart your dash to get to it. Extremely difficult (and dangerous if in neutral) to do on the trail.
8) 3-Amigos. Your traction Control system (3-lights generally indicate a problem: ABS, Engine Light, and BRAKE). The best way to keep up on this system? Spin the tires and engage the traction control ocassionally! It appears that city driven cars that never activate the TC have the valve body go bad and stuff. They can be rebuild, but again it's cost and $$. You do NOT want to permenantly disable traction control. Why? It protects your weak drive-shafts. A locked Disco 2 on stock shafts tend to shear axles. HD axles are available for $$ for those building rock crawler rigs. You can get 90% of the performance at a much reduced cost by going with True-trac geared limited slips and keeping your traction control in place. This tends to protect the axles from over-load and if an axle does break, it won't destroy the diff. The stock Traction Control will generally protect the axles from shearing. Generally, the mode of failure is the spider gears (if you disable the TC, spider shearing chances are increased). A locked disco will just chew through axles until you upgrade to HD. I'm waiting for my spider gears to shred, then I'll get True-Tracs.
Ok.....so I make it sound like the D2 is kind of a POS. Well, it's not like it appeared on the 10-worst car lists of all time for no reason! They are
Sounds like the D2 is junk just waiting to break. In a way...yeah. Something is always broke, but it will rarely leave you stranded. If you MAINTAIN your vehicle, it will last a long time. I bought mine with records for $5k, used in Moab, and it's still the most reliable used car I've ever bought. If you don't want to pay attention and maintain it, you might was something else. If you love the car, it has loads of character, is actually really good off-road, it's a solid overland platform, and the notorious engine is perfect for this kind of duty. And the D2's can be had for very little money these days!!
If you want a bit more reliability, save your $$ for a Jag powered LR3!! (Later model after the diff issues were worked out).
