How to purchase a used vehicle with confidence

I have a lot of experience buying used vehicles for my personal use and I also have a fair amount of experience performing repairs on those vehicles. I am not sure this is something to be envied, but it does make me something of an expert on the subject. I have a good track record with selecting low-cost, reliable cars and trucks, so I figure I might as well share my approach in the hopes that someone else may benefit from it.

If vehicle function and reliability (not appearance), are your goal, please start with a score of 0 and use the following procedure.

With the vehicle safely parked and the engine turned off, pop the hood and perform the following inspections:

  1. Remove the oil dipstick and examine the engine oil. Rub some of the oil on your fingertips. If you see radiator fluid (antifreeze) mixed in with the engine oil, DO NOT PURCHASE the vehicle. Otherwise, if the oil is at the recommended level on the dipstick and looks normal, add +1.
    Antifreeze in the oil pan means that the engine block is damaged and major repairs are in order.
  2. If equipped with a radiator overfill container and the warning label says that it is okay to remove the cap even when the engine is hot, then go ahead and pop the cap on the radiator overfill container. (Note that I am NOT referring to the radiator cap itself, which should never be removed if the engine is hot.) Rub some radiator fluid on your fingers. If you see evidence of engine oil mixed in with the fluid, DO NOT PURCHASE the vehicle. Otherwise, if the antifreeze liquid looks normal, add +1.
  3. On vehicles with automatic transmission, remove the transmission oil dipstick. Rub a small amount of transmission oil on your fingertips. Smell it and examine it visually. If you see metal pieces or shavings mixed with the oil, or if the oil has a strong burnt odor, DO NOT PURCHASE the vehicle.
    Metal shavings in the transmission oil indicate worn transmission components.
    Otherwise, if the oil is a bright red color and looks clean, add +1.
  4. Push down rapidly and strongly on the front left bumper and release.You want to see if the bumper returns immediately to its resting position and stays there, or if it bounces up and down repeatedly. Do the test on all four corners of the car. If it bounces no more than one or two times, add +1.
    Repeated bouncing means the shocks are worn and need to be replaced.
  5. Check the following fluid levels: brakes, power steering, antifreeze (use the overfill container or the radiator itself only if the engine is cold). If all fluid levels are within spec, add +1.
  6. Visual inspect the glass (windshield, windows, mirrors.) All in good condition? Add +1.

With the vehicle safely parked and the engine running at idle, pop the hood and perform the following visual inspections:

  1. Look underneath the vehicle for 30 seconds. If you see any visible dripping of oil, DO NOT PURCHASE the vehicle.
  2. Look at the engine (be extremely careful with moving parts such as belts and fans - do not get too close, careful with jewlery, necklaces, loose shirts, etc). If you see visible smoke coming from the engine area, DO NOT PURCHASE the vehicle.
    Smoke can be an indication of a cracked engine block - a costly repair.
  3. From a safe distance, visually inspect the radiator hoses (or as many of them as you can safely see). Add +1 if no leaks.
  4. If there is visible smoke coming out the exhaust pipe, DO NOT PURCHASE.
  5. Test the turn signals, brake lights, headlights, interior dome and dash lights and radio. If all function correctly, add +1.

Test drive the vehicle, making note of the following:

  1. The vehicle should start smoothly on the first or second turn of the ignition. Add +1.
  2. Pump the brakes. They should firm up. Add +1.
  3. Test drive it on city streets. There should be no unusual noises or handling issues. Add +1.
  4. Test drive on the highway. There should be no unusual noises or handling issues. Add +1.
  5. For automatic transmissions, the gear shifting should be smooth. If it slips or is hard to shift, DO NOT PURCHASE the vehicle.
    A slipping transmission is a dying transmission.
  6. Make sure the odometer and speedometer work. Add +1.

Peform the following tests if you have a safe place (like an empty parking lot) and if it is within your driving capabilities:

  1. Drive 15-25 mpg and use the steering wheel to weave the car from left to right, back and forth several times, as if you were weaving between cones in driving class. The vehicle should handle smoothly. The steering wheel should not be loose. Add +1.
  2. Drive slowly and then apply the brakes firmly to come to an brisk stop. The brakes should feel firm. The car should stop in a reasonable amount of space without the tires slipping. The vehicle should not bounce up and down repeatedly after stopping. Add +1.

Additional things:

  • If the original mileage is under 80,000, add +1.
  • Engine rebuilt within the past 6 years. +4
    For proof that the motor was rebuilt, ask the owner for receipts. If none are available, visually examine the engine. When an engine is rebuilt it is usually power washed and should be very clean top to bottom.
    A professionally rebuilt engine is a huge win. It means a major component won't have any big problems for years to come. Greatly improves the reliability factor.
  • Transmission rebuilt within the past 6 years. +4
    A professionally rebuilt engine is a huge win. It means a major component won't have any big problems for years to come. Greatly improves the reliability factor.
  • Ask the owner if there is anything on the vehicle that does not work. If he says everything works fine, add +1.
  • If the vehicle has ever blown a head gasket or had cooling issues (radiator), DO NOT PURCHASE. There is a good chance major damage has occurred.
  • Be wary of a vehicle on which cooling system components (radiator, water pump) have been replaced recently. Subtract -2.
    If the owner recently had cooling system repairs, there's a good chance the vehicle overheated. Overheating is one of the most damaging things that can happen to an engine. Prolonged overheating causes damage to gaskets, seals, and cylinders.


Add up the score. If higher than 12, then it's okay to purchase. You can feel reasonably confident you aren't facing major repairs in the foreseeable future.

Note that minor repairs are common in used vehicles and should not deter you from buying. Examples of typical minor repairs include replacing the following parts: alternator, starter, radiator hoses, belts, vacuum booster, brake pads, oil filters.