I just got one the other day (2004 w 129k). Here's what I did/would do if I were you... you don't really need a mechanic.

Before you leave:

-Wear clothes you can get dirty and bring gloves.
-Get a Carfax.
-Read all you can about issues with this car (there are very few, because I looked, mainly transmissions, and transfer case, some electronic issues but again very rare).
-bring a flashlight or two.
-Find out if they have a receipt for the timing belt change that should have occurred ay 60K. If they do not have this, it is a $1000 repair so keep that in mind when you nego.
-Ask about records... for 15k for Montero, it better be damn nice and have some documents.

When you arrive:

-Look the truck over, check all the gaps in all the body panels. They should be consistently spaced. Look at the sheen of the paint, it should be consistent all over. If you know what "orange peel" is, look for that. They rarely repaint without leaving it. Note anything that is inconsistent... a close gap on one side, a panel that is shinier than another, new paint or over spray on a window.

-Open the hood, check all the fluids. Coolant should be clear and usually green (though on this truck it can be orange as well). Trans fluid should be red. Engine oil should be cleanish and not black or burnt smelling. Power steering. Etc. etc. Take the flashlight, and shine it down all around the engine. Look for any leaks, new gaskets, or new parts. Look at the head of every bolt and nut you can see... have they been wrenched lately (note any dust or grit that has been disturbed or if the paint is damaged or if there a new nut on a bolt) anything like that. If something new is there find out why! Check the belts, are they new? or Cracked and have wear from age? I like to have an engine that has not been washed, and is dusty, etc. You can tell a lot more about it. They usually wash them, but only form the top of the engine.

-Now, here's why you have the dirty clothes. First ask them if they can put it up on a lift for you. They will probably make an excuse... but it never hurts to ask. When they say no, pull her up on a curb and get under the truck. It's pretty tall so you can slide under the thing pretty easily. Start at the front. Same routine as the engine... shine the light up and look for anything that might be a leak, or new gasket, of a part that has been replaced. Look for stripped screws or nuts that have been replaced. Is there new undercoat? Why? When was it applied? The ideal ride should have consistent parts (all the same age with the same level of dust and wear), look at fasteners around all the plastic panels. Are there replacements or missing fasteners? Why? Do this all the way from the front to the back of the truck. Trouble can be indicated by zip ties, metal clamps, hell even metal paper clips. If anything is out of place, look carefully around it, you can usually find the reason. If you find a leak, or a new gasket, or liquid gasket that doesn't look like OEM work (sloppy), then find out why it is there. New parts are not the end of the world, just find out why they are there. Look at the bottom of the suspension and skid plates, and the exhaust system. Are there scrapes, and are they beat to bits... then the owner probably had this thing off road A LOT! You can tell a world of info about a car from the underside.

Assuming all that is satisfactory, (new parts can be explained, no funny fixes or leaks) then take it for a drive. The drive will tell you everything too. How is the steering? Sloppy or tight? How is the shifting? Hard or soft? Be sure to go slow and let it shift, and wind it out as hard as you can. Shift into 4wd high and drive for a bit and 4wd low and drive for a bit. Hows the transfer case? Easy shifts or with big clunks? Cut the fan off, cut the radio off and listen... vibrations? Engine noise? Resistance from the trans? If the salesman is babbling tell him to shut up. It should all be right. Anything that didn't feel right probably is not. Don't ever let them tell you - "That valve noise, all Mitsubishi's do it"

Then go back in. Thank them, and start to leave. Then go back and offer $13k.

Then take it home and assume NONE of the right fluids are in it, drain everything and refill properly with THE RIGHT FLUIDS.

Then drive in peace.

No mechanic needed.

 

Wow, thanks for all that information! I'll be able to pretend like I know what I'm doing with that tidbit of information. I especially like the point of looking underneath the truck.

Is it safe for me to drive it in 4hl, what about 4ll? From what I've read, it's possible damage could occur if driven in these modes on pavement? I would take it ultra slow and not drive too long. I just want to make sure those work.

The 4WD system in the 2001 I test drove went haywire it seemed like. I tried 4H and it drove fine. Tried 4hl and it "seemed" like it worked. Then I put it back into 2H and the lights on the dash were blinking and the car would not move. Imagine applying the brakes and gas at the same time; this is what it felt like.

Anyways, I really appreciate the info.

 

Look for something that is a bit more forgiving than pavement as you drive the rig in 2 and all wheel, even a gravel drive or parking lot. Then pull in and try the other modes.
Although, driving in any mode in a straight line on pavement seems safe,
since you're only checking if all modes actually engage and operate.

Hell, if there's a trail around the area...take the thing wheelin', and really check out the system!

 

Well, I bought the Montero!!!

It ran great and shifted smoothly. When the engine is running you can barely notice it is on.

I ended up taking it to a mechanic just to double check things and they couldn't find anything wrong with it. As Skidmark suggested, I was able to look underneath the vehicle and didn't see anything alarming.

Hopefully it lasts a long time.

Thanks for everyone's help on this! I'm sure I'll have other questions now that it has been purchased, but those can wait until I start a new topic.

 

Congratulations!
Post some photos of the new rig when you get a chance.