Used Car Inspection Checklist

• Insist the car is cold. Ask the seller not to start it before you arrive. A warm engine hides hard starting, blue startup smoke and noisy lifters.
• Go in daylight and not in the rain. Water hides paintwork, filler and mismatched panels remarkably well.
• Run the VIN first. Check for open recalls and pull a vehicle history report before you spend an hour driving to see it.
• Bring the kit: flashlight, magnet wrapped in cloth, tire tread gauge, paper towel, OBD-II scanner and a friend.
• Know the market price for that exact trim, mileage and region so you are not negotiating blind — see how to negotiate a car price.

Do this part in daylight, on level ground, with the car dry and cold. A wet car hides paint defects, a warm hood hides a coolant leak, and a dealer lot at dusk hides both. If the seller can only meet you at night, meet them again in the morning.

1. 1

   Sight down each side of the car

   Crouch at one corner and look along the flank toward the other end. Ripples, waves and reflections that bend where they should be straight mean panel work.

2. 2

   Check every panel gap

   Gaps should be even and consistent side to side. A hood gap wider on one side, or a trunk lid that sits proud, points at a collision that pushed the structure.

3. 3

   Compare paint texture and color in sunlight

   Repainted panels often show a slightly different orange-peel texture or a subtle color shift. Overspray on rubber trim and door seals is a giveaway.

4. 4

   Measure tread depth on all four tires

   Below 4/32 inch means new tires soon, which is $600 to $1,000 on many vehicles. Uneven wear across the tread points at alignment or worn suspension — see wheel alignment cost.

5. 5

   Check the DOT date codes

   The last four digits of the DOT code are the week and year of manufacture. Tires over six years old are due regardless of tread, and four mismatched brands mean the car has been maintained by whatever was cheapest.

6. 6

   Look through the wheel at the rotors

   A deep lip at the outer edge and thin pads mean a brake job is close — budget from brake pad replacement cost.

You are not diagnosing anything here. You are looking for evidence of neglect and evidence of things being hidden.

Engine oil

Pull the dipstick onto a paper towel. Honey to dark brown is fine. Black and gritty means overdue changes. Milky or foamy means coolant in the oil — walk away.

Coolant

Should be clean and brightly colored in the reservoir. Rusty brown or an oily film on top is a serious warning. See coolant flush.

Transmission fluid

Where a dipstick exists, fluid should be red or pink and smell neutral. Dark brown fluid that smells burnt means the clutch packs have been overheating.

Belts and hoses

Squeeze the upper radiator hose when cold — it should be firm, not mushy or crunchy. Cracks on the ribbed side of the serpentine belt mean it is due.

Battery

Check the date sticker and look for white or blue corrosion on the terminals. Most batteries last three to five years.

Underside

Wet, shiny surfaces on the oil pan, transmission and differential mean active leaks. A light film of grime is normal on an older car; drips are not.

Twenty minutes minimum, with the radio off and the windows down for part of it. Include a highway on-ramp, a rough road, and an empty lot for slow-speed maneuvers.

1. 1Cold start. Listen for rattling in the first three seconds, and look in the mirror for blue or white smoke.
2. 2Brake hard once from about 45 mph on an empty road. Shudder through the wheel means rotors — see car shakes when braking. Pulling to one side means a caliper or alignment.
3. 3Hands off briefly on a flat, straight road. A steady drift means the car pulls to one side.
4. 4Full-throttle on the on-ramp. Watch for slipping between gears, flaring rpm, or a delay when the transmission downshifts.
5. 5Tight circles at walking pace with the windows down. Clicking means CV joints — see clicking noise when turning.
6. 6Rough road at 25 mph. Clunks over bumps point at sway bar links, struts or bushings.
7. 7Run the AC on max and the heat on max. AC that is not cold can be a $200 recharge or a $1,500 compressor.
8. 8Test every switch. Windows, locks, mirrors, sunroof, seat heaters, every speaker, the rear defroster and both key fobs.

These two steps catch what a walkaround cannot, and together they cost about the price of one set of tires.

Plug in your scanner with the engine off. Note stored codes, pending codes, and readiness monitors. Monitors showing not ready on a car that has clearly been driven means the codes were cleared recently — most likely this morning, most likely on purpose.

Most inspection findings are negotiating points. These are not. Each one either costs more than the car is worth to put right or tells you the seller is not being straight with you, and there is always another car.

• Milky oil or oil in the coolant. Head gasket or worse.
• A branded title — salvage, rebuilt, flood or lemon — unless you are buying at a steep discount with eyes open and no plan to resell.
• Odometer or service history that does not line up with the wear on the pedals, seat and steering wheel.
• Musty smell, silt under the carpet, or corrosion on the seat rails and under-dash connectors. Flood damage causes electrical faults for years.
• No title in the seller's name, or a title with a lienholder still listed and no payoff letter.
• A transmission that slips, flares or bangs into gear. The gap between a fluid service and a rebuild is roughly a factor of twenty in cost.