Originally posted by: FallenHero
Rattling, accleration problems, any hesitation on shifting gears if automatic. The car gurus can name more I am sure
Yep, those are big ones. Also, check the tires...if there's a lot of wear on the outside edges of the front tires, he's either been taking a lot of hard corners, or has terrible alignment. If the front tires are much more worn than the rears, and you see little black streaks on the wheel wells, he's been doing burnouts. If there are spots on the rear where the tread is gone, but most of it is OK, he's been fake-drifting by pulling the handbrake around corners.
Listen to the engine. Listen to it at idle, and at higher RPMs, and under load. Lots of times you can hear problems, like ticking at idle, a "marbles-in-a-can" sound under load, buzziness, whatever. Be sure the engine is COLD when you show up to drive it. If it's already warm, it COULD be that the guy was trying to be nice and warm it up for you, or it could be that they're trying to hide something (engines always run better when warm). After taking it out and driving it (be sure to drive it HARD for at least part of the test drive...if there are problems, they may not show up if you take it easy), park it, and check for leaks. Putting white paper down under the car can help. Look at the engine, too. If it's clean, that's good. If it's dirty, be careful, it might not have been well taken care of, or it might have a leak. If it's SPARKLING, either the guy takes really good care of his cars, or just got it steam cleaned (now why would they do that...).
Go over some bumps. Listen for noises from the shocks. Make sure it "feels" right, not too bouncy, not too stiff, good dampening. Take a few hard turns, a few soft turns, a full-lock turn in each direction while accelerating, turn the wheel lock-to-lock at a standstill. You shouldn't hear any moaning sounds, any ticking from the CV joints, anything suspicious.
Check all fluids. Oil will probably be a clean black, unless it's been VERY recently changed (why would they...) If there are particles, RUN AWAY. If there's any oil in the coolant or vice versa, RUN AWAY. If the dipstick is dry...need I say more? Check the other fluids--coolant, tranny, power steering, brake, etc--to make sure they're topped off and look "right." ("wrong" tends to be pretty obvious).
Test the brakes. Going 30-40, slowly brake to a stop. Get back up to speed, slam on the brakes. Drive the car hard, with a lot of fast stops, and see if you get any shuddering in the steering wheel or in your seat (warped rotors). The pedal should be firm, and when you hold the brakes at a given pressure it shouldn't sink down from that point.
Look at the exhaust. Smoking? Blue smoke (oil), black smoke (gas), or white smoke (water)? Car exhaust should be almost invisible, except on a cold day.