Dang good advice people, thanks John!
Does the dealer have any service records, history reports, inspection reports? I'd take it to a Ford dealer (as in, a different one if you're buying it from a Ford dealer) for a mechanical inspection. Most wont charge much if anything in the hopes to sell you work. At the most, it'll be less than $100 for sure. I remember that I never charged custumers for used-vehicle inspections when I was at the Lincoln-Mercury dealer, so long as nothing was done to the car aside from a routiene visual inspection and possible a test drive. Usually, if the car needed work and they ended up buying the car, they'd bring it back to me to get it fixed, or have the seller pay me to fix it, lol.
As for you personally inspecting the Taurus at the lot, these are the general steps I take when previwing a possible used car for purchase. Dont let the sale person rush you, its your buisness thats being earned, not his. If he protests to your inspection, walk away. He's either hiding somthing or doesnt care about you or your buisness. Either way, screw 'em, LMAO.
I appologize if this may seem too basic to you, but frankly I dont know the extent of your automotive knowledge so if thats the case, bear with me. This is taylored to a Ford Taurus but is mostly applicable to any used car. I've gone from not openening the hood on a used car to down right getting my clothes dirty crawling underneath to inspect it. Trust me, its worth the time and effort to ensure you dont end up with someone elses problem car.
Before running the car (as in, when its cold and hasnt been recently ran), walk all the way around it and check for paint not matching. If the car was partially repainted, some of it will be glossy and new-like while the rest may look more dull and faded. If you find a spot where you suspect body work has been done, inquire to the seller and take a look underneath the car in that area. Look for signs of welding or other recent work. Having some minor body damage repaired isnt bad thing always, a healthy majority of used cars have had some level of body work done at some point, most undetected by their new owners and usually, it wont effect the performance or look of the car. While your out side and walking around the car, inspect all four tires. Are they the same brand, size, etc? Do they have fairly even wear patterns? If all are the same size, brand, etc but one is MUCH more worn than the others, or in a different pattern/area, this suggests possible alignment problems. Peak at the exhaust, is it heavily rusted? Speaking of which, is the car itself rusty anywhere? Even if you live in a non-rust prone area, check for it, because some people transport good-but-rusty-underneath cars away to non-rust prone areas to sell them for more to people who dont know to look. One person I knew bought a late 80s Nissan 4x4 in the south west, turns out it was a Canadian truck and had extensive rust damage to its fame, to the point that it was unrepairable. He spent $2K+ on a $200 truck.
Without having started the car at this point, pop the hood. Check all fluids, including coolant, power steering, brake (usually not neccissary to take the cap off as the resivor should be clear and have "MIN" and "MAX" lines on the side), and engine oil. It is not neccessary at this point to check the trans fluid, as this should be done with the car running and at normal operating temp. Inspect the engine bay for loose wires, wet spots (suggesting leaks), disconected hoses or wires, etc. Inspect the air filter. Inquire about the fuel filter, plugs, wires and the oil change intervals. If the engine oil is a little low and/or dark, dont worry too much, its just due for an oil change and most any 10+ year old car will use some oil during the 3,000 miles beween changes. If the oil is extreamly black and/or smells really burnt, becareful. Also, if its milkshake-like, this is a sign of a blown head gasket, a costly repair.
Moving on: Look at the belt (on the left side of the engine), does it have cracks? If so, dont worry, its easily replacable. If it is pretty cracked and worn, ask the dealer if they are willing to do it or if they will pay for it to be changed elsewhere. If the car has been sitting in one spot for a while, check undeneath for drips. Get down low and look up into the engine bay from the bottom. The bottom of the engine is most likely covered in grime, grease, oil, etc, and this is normal, but look for signs of major leaks. Look at the oil pan and trans pans, are there drips? If so, are they bad or just minor? Its not unlikely that the car leaks some oil, but it shouldnt be excessive and any trans leaks require immidiate attention. You DO NOT want to get the trans low on fluid. Inquire about how long its been since the last trans flush INCLUDING filter and pan-gasket change.
When you are out side of the car, look for any further signs of damage. Open all of the doors, see if they shut well. Look at the door sills, are they a different color or show signs of recent work (as in welding, etc)? Now you can crank the car, put the drivers side window down, get out and close the door. At this point you could take the oppertunity to inspect the exterior lighting, including the license plate lamps and the small marker lamps towards the outside of the headlamps. They are supposed to light up when the parking lamps are on (and headlamps accordingly).
Listen to the car from all angles, sides, etc. Is the exhaust excessivly loud? Is it loud towards the middle or front of the car (suggesting an exhaust leak)? listen to the idle, is it fairly consistant with pretty much no or very limited surging (revving up and down on its own)? It should run at around 1300 to 1500 RPMs when started cold for a moment. Slowly, the idle will lower down on is own to around 950-1K RPMs. If it doesnt, there may be something going on with the computer, a sensor, or a vaccume leak. Walk all the way around the car with it running. Listen towards the back of the car for a loud, high-pitched humming noise. This is the fuel pump. Excessivly loud fuel pumps usually mean they are old and prone to failure. Also, if it keeps going back up to the higher RPM and lowering (as my '93 does, LOL), watch for this. Reach inside after you've walked around it a few times and pop the trunk. Check the spare. Check the spare tire compartment for water or excessive moisture (some moisture is normal if the car has been sitting, but not so much as to form a puddle). Look for rust. Look for recent weld spots on the bare metal or damage as if its been pushed in and hammered back out (suggesting the car was rear-ended hard). If it smells musty, dont worry too much unelss you detect rust or excessive water.
Now, go get in the car, drivers seat. Turn on the heat, full blast, pannel vents and (if you want) floor selection. By this time, the car should be warm enough to produce heat inside assuming the coolant is full and there isnt any obstructions in the cooling system. I dont care if its 85 degrees, this is important. If the car is taking a very long time to warm up, that means the thermostat is either missing or stuck open and should be replaced. Try to smell as best you can the air coming from the vents inside the car when the heat is on. If it smells old, stail, and/or moldy, its a sign the car has been sitting. If it smells like coolant AND/OR the windshiled keeps fogging up, its a definant sign that the heater core is going out and that can be a costly repair. Check all the accessories. Wipers? On intermitant, wash, and just "ON" or "HIGH". Power options including windows, seat, door locks, and mirrors. Horn? Radio? All interior lighting? The seller should warn you of a non-functioning power options before hand. Are all the gauges working? If the car has 'too-good-to-be-true' low miles, look for missing screws, scratches, scuffs, etc on/around the gauge cluster and surrounding bezel.
By this time, the temp needle should be creaping above the blue line towards the "N O R" in the word "N O R M A L" on the temp gauge. Wait until its at least above the first leter in that word before you attempt to drive the car. Continue testing out every feature, accessory, button, knob, etc. Open the center console, if so equipped, and the glove box. Are any dash lights staying on (aside from DOOR AJAR and/or the seat belt remindor)? Ask if the A/C works. If they say yes, select "COOL" on the temp selector and then turn the dial to "MAX A/C". You should hear a movement under the dash, thats the blendor changing the settings you requested (as in, block off air coming in from outside the vehicle, "MAX A/C" recirculates air inside the cabin instead of drawing it in from the outside). Listen to the engine carefully. You should be able to hear the compressor kick on. At the same time, the RPMS may drop a little and the cooling fan under the hood should engauge. If none or not all of this is happeneing, there is most likely a problem with the A/C. Its either out/low of charge, the compressor has failed, or the HVAC selector isnt working properly. If the compressor keeps cycling on and off frequently, it means the system is low on refrigerant. By this point, the car should be at normal opperating temp and ready to drive. Just wait, there's more before you drive it.
Back to the engine bay. Listen under the hood (as its running) for loud hissing, grinding, or tapping. There may be slight amouts of each, but none of that should be loud. Look carefully for dripping and use your sence of smell. Do you smell burning? If so, try to pinpoint where its coming from. Now that the engine is warm, check the trans fluid. It shouldnt smell burn, it shouldt be dark, and it shouldt be low. It should be bright pink. If not, it may just need a flush. If it smells burnt or is low, recondisor driving it and plan to have it inspected closer by a trained technition (NOT AAMCO).
Close the hood and any other exterior doors and/or deck lid.
Get back in the car, turn the steering wheel from lock-to-lock. Is the powersteering pump excessivly loud (a whining noise coming from the passenger side of the engine bay)? Does the wheel "catch" every so often? Do you hear/feel popping or thumping noises? These could be signs that the pump (or other steering/suspension/drive componants like the tie rods, CV axels, or strut mounts) and/or rack are failing. Both the pump and rack are somewhat common on Taurus' as they age and aquire high mileage. The pump could cost anywhere from $60 to $150 for a reman'ed one, I paid in the low $70s for the one for my '93 at AutoZone and its equipped with a Lifetime Limited warranty.
Now, FINNALY, you are ready to drive it. Drive it normally, but then again put it through its paces. Its not a sports car (as you know having previously owned a Tauurs), but it should handel fairly well, ride pretty smooth without excessive bounce, and not make any clunks, creaks, or other obnoxious noises. Test the brakes. If you feel a vibration when slowing down, the brake rotors are most likely warped (common).
Do some acceleration runs, and not just WOT up to 100 MPH, LOL and not just 0-60 either. More like everyday driving, for example two-lane passing (45-60) and in town acceleration (25-40, etc). Pay attention for trans slips or major hesitation from the powertrain. Hearing pinging noises from the engine and slow up-hill acceleration are signs the engine is in need of a tune up. Feel for any shuddering under hard acceleration. If present, its time for a trans flush/filter/pan-gasket change. Granted, the shifts of this automatic tansaxel are naturally kinda lazy, but there shouldnt be a whole lot of excessive revving and certainly no revving-but-no-going, lol. Try to drive it on a road you can maintain a fair amount of speed on (50 MPH +). Test the cruise control. Feel for vibrations through the steering wheel. This could be a bent rim, failing tire, or more seroius problems in the suspension (unlikly but possible if its been wrecked)
Check the trans fluid immidiatly after you get back from the test drive, without having shut off the car. Becareful, the engine's hot and so may be the trans dip stock. The trans fluid should be full and pink, not dark. It shouldnt smell burnt. After you shut off the car, listen under the hood (and around the car) for abnormal noises. After having sat for less than a minute, restart the car. Did it start normally? Any abnormal noises? Now try doing the engaugement test again with the trans. Its more likely a lot smoother now that the car is warm.
Shut it down and walk around the car again. Any smoke? Any steam? Smell coolant or burning oil/hydrolic fluid? Look under it again to see if there are any drips (having parked it in a different spot than before if possible).
Dont forget to test EVERYTHING even if you dont use it right now (like A/C in early fall, depending on your climate). A guy came into AutoZone yesterday and said he bought his S10 5-6 months ago at a dealer and hadnt used the wipers until that morning, upon which he discovered that they didnt work!
Drive the car as you normally would. If you do 85 MPH on the freeway, do 85 on the freeway during the test drive if possible. (Warning: be carefull about accelerating a car you're not used to up to high speeds. Do it slowly, and listen/feel for vibrations and/or noises. Do not proceed if they are present. You never know, the tire could be on the verge of coming apart, or the suspension may be weak from an accident or excessive wear/tear, etc.)
Dang good advice people, thanks John!