Buying a used car
The used car test drive checklist
What should you look for on a used car test drive?
Drive a route you choose that includes rough pavement, a highway on-ramp at full throttle, a steady cruise near 60 mph, a firm stop from 45 mph, and full-lock turns in a parking lot. Keep the radio off and listen for clunks, driveline vibration, harsh shifts, and brake pulsation.
Plan the route before you turn the key
A ten minute loop around a quiet block confirms almost nothing. A useful test drive needs four different conditions, and on Long Island all four are easy to find within a few miles of one another: a broken residential surface, a stretch of stop and go on a road like Wantagh Avenue or Sunrise Highway, a full-throttle merge onto a parkway, and an empty parking lot for slow-speed maneuvering.
Ask for at least twenty-five minutes. Transmissions that shift correctly cold can shift poorly once the fluid is hot, cooling systems reveal themselves only after the thermostat has opened and closed a few times, and an air conditioning system that seems fine for two minutes can lose its bite after ten. A short drive systematically favors the car.
Tell the seller the route in advance rather than negotiating it in traffic. A seller who is comfortable with the vehicle will not object. A seller who steers you away from the highway portion has told you something before you leave the driveway. Agreeing it beforehand also removes the awkward mid-drive request, which a seller can decline without seeming to, leaving you circling a familiar block at 30 mph.
A route that actually tests the car
- Cold start with the hood open, listening for the first thirty seconds of idle
- Rough residential pavement at 25 to 35 mph, windows down, listening for clunks
- Stop and go traffic for at least five minutes, watching the temperature gauge
- A full-throttle on-ramp merge, feeling for hesitation, flare, or a harsh shift
- Steady 60 to 65 mph for several minutes, hands light on the wheel, feeling for vibration
- A firm stop from about 45 mph on a clear stretch, feeling for pulsation or pull
- Full-lock turns both directions in a parking lot, listening for clicking or groaning
- A final two minutes at idle with the air conditioning on maximum before shutdown
The first ninety seconds tell you more than the next ten minutes
Before starting, turn the key to the accessory position and watch the instrument cluster. Every warning lamp should illuminate and then extinguish once the engine runs. A check engine lamp that never illuminates at all can mean the bulb has been removed, which is worth noticing on a car that has to pass a New York emissions inspection.
On the cold start, listen for the cranking speed, for a brief rattle from a timing chain or a hydraulic lifter, and for exhaust noise that is louder than it should be. A puff of blue smoke that clears in seconds suggests valve stem seals; white smoke that persists and smells sweet suggests coolant. Both are findings, not necessarily deal breakers, but both need pricing.
With the vehicle stationary and in gear, note whether it creeps normally, whether the brake pedal sinks slowly under steady pressure, and whether the steering wheel sits centered when the wheels are straight. A pedal that sinks points to a master cylinder or a leak. An off-center wheel points to an alignment that was never corrected, sometimes after a curb strike.
What broken pavement reveals about the suspension
Suspension wear is nearly silent on smooth asphalt and obvious on a frost-heaved side street. Drive with the windows down at 25 to 35 mph over the worst surface you can find legally. A single sharp clunk from one corner when the wheel drops into a dip usually points to a sway bar end link, which is a modest repair. A duller repeated knock often means control arm bushings or a strut mount.
Pay attention to what the car does after a bump rather than during it. A healthy shock absorber allows one compression and one rebound. If the body continues to move up and down after a single dip, the dampers are worn, and worn dampers wear tires in the cupped pattern you may already have felt on the tread.
Long Island roads make this test easy to run and important to run. Winter freeze and thaw cycles combined with heavy parkway traffic produce exactly the kind of surface that finds tired suspension components, and a car that has spent its life here has been living on that surface. Ask where the car was usually driven as well, because a vehicle that spent years on these surfaces has already taken the punishment your test drive is simulating.
The merge and the cruise: transmission, driveline, and balance
Take an on-ramp at full throttle. An automatic transmission should downshift promptly and hold the gear without slipping. Watch for a flare, where engine speed rises briefly between gears while the car does not accelerate, and for a shift that arrives as a jolt rather than a swell. Either can mean fluid that has never been changed or clutch pack wear, and the difference in repair cost between those is very large.
At a steady 60 to 65 mph, rest your hands lightly on the wheel and pay attention to where any vibration comes from. Vibration felt through the steering wheel usually originates at the front wheels, commonly imbalance or a bent rim from a pothole. Vibration felt through the seat is more often rear wheels, driveshaft, or tire belt separation. Note the speed at which it appears and whether it changes when you lift off the throttle.
Then hold a light, steady throttle and listen. A droning hum that rises and falls with vehicle speed but not engine speed is a wheel bearing until proven otherwise, and it will often change pitch when you sway gently within your lane. That test is easiest on a lightly trafficked stretch, not in a parkway rush.
Braking and low-speed steering tests
Find a clear, straight stretch and make one firm stop from about 45 mph. Pulsation felt in the pedal means rotor thickness variation, which is a rotor and pad job. A pull to one side means a sticking caliper, a collapsed flexible hose, or uneven pad deposits. A long, soft pedal travel means air, a leak, or fluid that has absorbed moisture over years, which is common on a car that has never had a brake fluid service.
In an empty parking lot, turn the wheel to full lock in each direction and drive slowly in a circle. A rhythmic clicking that speeds up with wheel speed on a front-wheel-drive car is a worn outer constant velocity joint. A groan or shudder through the wheel points to a power steering issue or a binding strut bearing.
Finish by reversing in a straight line and braking gently. Some brake and suspension noises appear only in reverse, and a rear brake that grinds only in reverse is a clue worth having before purchase rather than after. Reverse also loads the suspension bushings in the opposite direction, so a worn control arm bushing that stayed quiet going forward will sometimes give a single knock as the slack is taken up. Do this at walking pace in an empty lot rather than on a street.
What to do in the first five minutes after you park
Leave the engine running and let it idle for two minutes with the air conditioning on maximum. Cooling fans should cycle audibly, the temperature gauge should stay where it settled, and the idle should not hunt or dip when the compressor engages. Then shut it down and open the hood while everything is hot. Watch the tachometer as the compressor cycles, because an idle that dips noticeably each time it engages suggests the engine is working harder than it should to hold it.
Look for wetness at the front and rear of the valve cover, along the oil pan seam, and around the water pump. Smell for burning oil, which reaches a hot exhaust and produces a distinct acrid odor, and for hot coolant, which is sweet. Then look at the ground under the car for two or three minutes; fresh drips show up quickly on dry pavement.
Finally, check the wheels with the back of your hand held near each one. A wheel that is markedly hotter than the other on the same axle after gentle driving suggests a dragging brake caliper. That is a repair with a price, and it is far better identified in a parking lot than on a bill three weeks later.
Useful answers
More questions about buying a used car
How long should a used car test drive be?
At least twenty to twenty-five minutes, including highway speed. Shorter drives keep the engine, transmission, and air conditioning below the temperatures where many faults appear. If a dealership or seller allows an extended drive, a longer route that includes your normal commute conditions is more informative still.
Can I take a used car on the highway during a test drive?
Most sellers allow it, and any test drive that omits sustained highway speed leaves driveline vibration, wheel bearings, and transmission lockup behavior untested. Ask before you set out so the route is agreed. Insurance arrangements vary between dealerships and private sellers, so confirm coverage first.
What does a vibration at 60 mph mean on a used car?
Most often wheel imbalance or a bent rim, both common after pothole impacts. It can also be a separated tire belt, a worn driveline component, or a warped brake rotor if it appears mainly under braking. Note whether you feel it in the wheel or the seat, which narrows it to the front or rear.
Should I test drive a car cold or warm?
Cold, then warm. A cold start reveals startup smoke, cranking speed, and initial idle quality that disappear within minutes. Then drive long enough for full operating temperature, because hot transmission fluid, a heat-soaked cooling system, and a loaded air conditioning system each expose different faults.
What if the check engine light comes on during the test drive?
Stop the negotiation and get the code read before going further. A lit lamp will also fail the emissions portion of a New York State inspection. Some causes are inexpensive, such as an evaporative system leak from a loose fuel cap, and some are not, so the code determines what happens next.
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