The full list of what we find inspecting used cars — every common fault with real examples from our reports, and how the odds of getting a good car change with age, mileage and price. Based on 5,025 pre-purchase inspections.
"Good" means a condition score of 60+/100. Each line is the share of inspected cars that made that bar. Click or drag across a chart to filter the fault list below to that age, mileage or price.
Sorted by how often we flag each item. The percentages are the share of all inspected cars; the examples are actual findings from our reports.
Engine oil leaks are not cheap to fix, but, in most cases, they can't affect the car's reliability. An exception is a head gasket oil leak, which may indicate more serious issues in the future.
Typical findings: timing chain cover oil leak · valve cover gasket oil leak · oil pan leak
The overall condition and remaining tread of the tires, including uneven or excessive wear. Worn or mismatched tires are an immediate cost, and an unusual wear pattern often reveals an alignment or suspension problem underneath.
Typical findings: front tires are different · rear tires are different · tires need replacement
The main factor that shows a general condition of the engine: intake, fuel, ignition systems. Ideally, it should be around 0% which means that all system work as expected. Acceptable fluctuation +/-5%. Bigger values indicate that ECU had to increase or decrease fuel injection due to some issues in order to keep the optimum air-fuel ratio.
Typical findings: -7.0% · 8.5% · 7.0%
In most cases, cooling system issues are not expensive to fix, but ignoring them can cause engine overheating, leading to major problems like a blown head gasket or even damaged piston rings.
Typical findings: low coolant level · coolant level below the minimum · low coolant level (possible coolant leak)
A check that the exterior and interior lights work — headlights, brake lights, turn signals, reverse and plate lights. A dead bulb is trivial, but a circuit that does not work can point to wiring or module faults and is an instant registration or safety issue.
Typical findings: license plate lights don't work · right license plate bulb doesn't work · left license plate light doesn't work
The rubber bushings that locate the suspension arms and subframe. Cracked, torn or perished bushings cause clunks, vague handling and uneven tire wear; replacement ranges from cheap to labor-intensive depending on location.
Typical findings: front rubber bushings are cracked · front rubber bushings are cracked (no replacement needed so far) · front rubber bushings are torn
Leaks of power-steering fluid, typically from the pump, hoses or rack seals. A low system leads to heavy or noisy steering and, left unchecked, to pump or rack damage.
Typical findings: steering rack leak · power steering pump leak · steering rack leak (left seal)
Leaks of transmission fluid, usually from the pan gasket, seals or cooler lines. Running low from an untreated leak is a common cause of harsh shifting and, eventually, expensive transmission failure.
Typical findings: oil pan leak · oil pan leak (minor) · oil residue on the bottom of transmission housing
The dampers that control body movement over bumps. Leaking, worn or weak shocks lengthen stopping distances, hurt stability and wear tires unevenly, and are usually replaced in pairs.
Typical findings: front right shock absorber is leaking · front left shock absorber is leaking · rear right shock absorber is leaking
A scan of the engine control modules for stored and active trouble codes. Active codes point to a fault the car is detecting right now; they often explain a check-engine light and should be understood before you buy.
Typical findings: Active error code: P0420 (catalyst system efficiency below threshold) · Active error code: P1604 (startability malfunction) · Saved (not active) error code: P0420 (catalyst system, bank 1 - efficiency below threshold
Abnormal noises indicate serious and hard to fix problems with valvetrain, bearings, chain, cylinder-piston group. It's essential to determine and localize these noises.
Typical findings: one of the pulleys makes a noise · belt tensioner makes noise · fuel pump makes excessive noise (may need replacement soon)
A visual check of the suspension ball joints and mounting points for play, split protective boots or corrosion. Worn joints cause knocking and imprecise steering and, once a boot has failed, tend to deteriorate quickly.
Typical findings: torn boots on front sway bar links · torn boots on the front sway bar links · torn boot on the front right sway bar link
Oil condition and level are crucial for engine reliability. If the oil is too dirty or, far worse, too low, irreversible damage may already have occurred.
Typical findings: dirty, level ok · dirty, level is below the minimum · clean, level is low
A Tire Pressure Monitoring System (TPMS) is an electronic system in vehicles that monitors the air pressure inside the tires and alerts the driver if the pressure is too low or, in some cases, too high. It enhances safety, fuel efficiency, and tire longevity by ensuring tires are properly inflated.
Typical findings: Active error code: C2121, C2122, C2124, C2125 - cannot receive a data from transmitters · Active error code: C2124 (cannot receive a data from the transmitter ID4) · Active error code: C0077 (low tire pressure)
The condition of the brake discs (rotors). Deep scoring, ridges, thinning or heavy rust pitting reduce braking and usually mean the discs need machining or replacement along with the pads.
Typical findings: front brake rotors are warped (vibration on braking) · front brake rotors are slightly warped (some vibration on braking) · vibration when braking (warped rotors)
A recent repair is often not ideal when buying a car. Sellers may prioritize cost over quality parts and labor, potentially affecting the car's long-term reliability.
Typical findings: loose clamp on the intake boot after the air filter housing · the battery is not fixed in place · the engine was rebuilt
Leaks from the differential, transfer case or axle seals. Losing oil from these units accelerates wear and, if run dry, can cause expensive failure.
Typical findings: rear differential oil leak · transfer case oil leak · oil residue on the rear differential (minor, no repair needed so far)
Whether the car tracks straight or pulls to one side. A pull can come from something as simple as uneven tire pressure or alignment, or from worn suspension and steering parts or a dragging brake.
Typical findings: steering wheel is not centered · pulls to the right, needs alignment · steering wheel is not centered (needs wheel alignment)
The air conditioning's ability to cool. Weak cooling usually means low refrigerant (often from a leak), a failing compressor or a blocked condenser — repairs that range from cheap to significant.
Typical findings: doesn't work · low efficiency · does not work
Knocks, creaks or rattles from the suspension over bumps. These usually point to worn bushings, ball joints, links or shock mounts and are worth pinning down before buying.
Typical findings: rattling on bumps · rattling on bumps - needs to check sway bar links · rattling on bumps - needs to check front ball joints
The free play at the steering wheel before the wheels respond. Excessive play points to wear in the steering rack, joints or linkage and makes the car feel vague and imprecise.
Typical findings: present · present (small) · present (big)
Vibration felt through the car while driving, often traced to the driveshaft, CV joints or worn universal joints. Persistent vibration should be diagnosed, as it tends to worsen and can damage related parts.
Typical findings: vibration after 60mph - unbalanced tires or bent rims · vibration after 50mph - unbalanced tires or bent rims · vibration after 60mph (unbalanced tires or bent rims)
The rubber boots that seal the CV joints on the driveshafts. A torn boot flings out grease and lets in dirt, ruining the joint — cheap to fix early, costly once the joint is damaged.
Typical findings: left inner CV-joint boot is losing grease · inner CV-joint boots are losing grease · right inner CV-joint is losing grease
The instrument cluster and its warning lights. Missing gauges, dead pixels, or warning lamps that stay on (or were disabled) can hide real faults and should be explained.
Typical findings: audio system doesn't work · volume control knob doesn't work · yellowish central display
The windshield washer pump, jets and reservoir. Usually a minor fix, but a washer that does not work is both a safety and an inspection item.
Typical findings: doesn't work · rear washer doesn't work · doesn't work (water leak)
The operation of the electric windows. Slow, noisy or dead windows usually mean a worn regulator or motor — a common and moderately priced repair.
Typical findings: rear right power window doesn't work · driver's power window doesn't work · rear left power window doesn't work
A scan of the climate-control modules for fault codes. Codes can point to blend-door actuators, sensors or the compressor clutch that affect heating and cooling.
Typical findings: Active error code: B2631 (sun load sensor) · Active error code: B1421 (solar sensor circuit - passenger side), B1424 (solar sensor circ · Active error code: B1421 (solar sensor circuit - passenger side)
How cleanly the transmission engages and shifts. Slipping, flaring, harsh bangs or delayed engagement are early signs of internal wear and can foreshadow a costly rebuild.
Typical findings: jerks when shifting · engine revs are fluctuating during acceleration on 2-nd and following gears - possible iss · slightly jerks when shifting
How much friction material is left on the brake pads. Pads worn near their limit are a near-term expense and, if left, score the discs and reduce braking.
Typical findings: front brake pads will need replacement soon · rear brake pads will need replacement soon · rear brake pads need replacement
The condition and adjustment of the seats, including powered movement and heating where fitted. Wear beyond the car's age can hint at higher real mileage, and power-seat faults can be costly.
Typical findings: driver's seat is loose · driver's lumbar support adjustment doesn't work · driver's seat lumbar support adjustment doesn't work
The central locking and individual door latches, including remote operation. Intermittent locking often points to a worn actuator or broken wiring in the door harness.
Typical findings: trunk lid release button doesn't work (on the trunk) · power locks don't work · driver's door power lock doesn't work
The electric adjustment — and folding or heating where fitted — of the door mirrors. Faults are usually a switch, motor or wiring problem.
Typical findings: don't work · right power mirror doesn't work · right power mirror doesn't move left/right
The remote key fob buttons and remote locking. A weak or failed fob may just need a battery, but a missing spare key is a real cost to replace and program.
Typical findings: doesn't work · one of two key fobs doesn't work · battery needs replacement
The condition of the accessory drive belt and, where visible, the timing belt. Cracked, glazed or frayed belts are inexpensive to replace but can leave you stranded — and a failed timing belt can cause major engine damage — so their state and replacement history matter.
Typical findings: cracked · belt needs replacement · cracked - needs replacement
Whether air reaches the selected vents at the right temperature. Faults usually trace to a stuck blend or mode door — often a failed actuator — behind the dashboard.
Typical findings: doesn't work · doesn't work (blows only through dash vent) · always blows through dash air vents
The color and level of the power-steering fluid. Dark or contaminated fluid suggests wear inside the pump or rack, while a low level usually means a leak.
Typical findings: clean, level is below the minimum · clean, level is low · dirty, level ok
Vibrations are commons sign of uneven combustions among engine cylinders. It may also indicate unbalanced crankshaft, flywheel or torn engine mounts.
Typical findings: vibration at idle · vibration at idle (needs to check engine mounts) · vibration at idle - needs to check engine mounts
A scan of the airbag and supplemental-restraint system for fault codes. An illuminated SRS light or stored code can mean an airbag, seat-belt pretensioner or crash sensor is disabled — a safety-critical item that must be resolved.
Typical findings: no connection, warning light is on · Active error code: 09-03 (faulty driver's seat belt buckle switch) - the system doesn't wo · Active error code: B0020-13 (open or increased resistance in the left side airbag inflator
Typical findings: top engine mount is torn · top engine mount is cracked · front engine mount is torn
The blower and cooling-fan bearings. A whirring or rumbling fan bearing is a wear item that will eventually seize and stop airflow.
Typical findings: worn out (makes noise and vibrates) · worn out (makes noise) · makes noise (worn out)
Typical findings: Active error code: P1009-00 (humidity sensor module) · Active error code: B3109 (keyless entry transmitter 1 battery) · Active error code: B3883-04 (license plate lamp circuit open)
The wiper motor, linkage and blades. Streaking, juddering or a slow or mis-parking wiper affects visibility and ranges from a cheap blade to a motor or linkage repair.
Typical findings: wiper blades need replacement · rear wiper blade needs replacement · doesn't work
The rubber boots that protect the steering rack ends and tie-rod joints. A split boot lets grit and water in and leads to rapid wear of the joint it was protecting.
Typical findings: right steering rack boot is torn · steering rack boots are torn · left steering rack boot is torn
Typical findings: leaks · aftermarket, loud · leaks (in the middle)
Oil sludge, deposits inside the engine suggests poor maintenance and may cause piston rings to seize, leading to excessive oil consumption.
Typical findings: present (irregular oil changing) · present · Evidence of small sludge build up inside the valve cover
The color, smell and level of the transmission fluid. Dark, burnt-smelling or low fluid indicates overheating or neglect and often precedes shifting problems.
Typical findings: dirty, level ok · clean, level is below the minimum · clean, level below minimum
The heater's ability to warm the cabin. Weak heat can be as simple as low coolant or a stuck blend door, or as involved as a blocked heater core.
Typical findings: doesn't work · low efficiency · doesn't work on the driver's side
The bearings that let each wheel spin freely. A worn bearing produces a droning or grinding noise that rises with speed and, if ignored, can seize the wheel.
Typical findings: one of the rear wheel bearings makes a noise · one of the rear wheel bearings makes a noise (minor, no repair needed so far) · front right wheel bearing is worn out (makes noise)
A scan of the transmission control module for stored and active fault codes. Codes here can indicate solenoid, sensor or clutch-pack problems that affect how the gearbox shifts.
Typical findings: Active error code: P17F1 (CVT judder) · Saved (not active) error code: P0877 (transmission fluid pressure switch 4 circuit low vol · Saved (not active) error code: P0868 (fluid pressure low)
← Back to Used car insights · based on 5,025 inspections · updated Jul 12, 2026
