Skip to content

Access keys for nzta.govt.nz

  • h Home
  • m Menu
  • 0 Show list of access keys
  • 2 Skip to content
  • 3 Skip to top

Tips for buying a used car

Inspection tips

  • Take your time and carefully examine everything you want to look at – not just what the seller shows you.

  • Inspect the car on a dry sunny day if possible – it's easier to see the visual clues to the car's real condition. See our safety checklist.

  • The older and cheaper the car, the more likely there will be something wrong, particularly once it's done more than 100,000km. Be especially wary of engine wear and rust.

  • Know what you can fix and the cost of having the work done.

  • Take these inspection aids:

    • checklist of things to look for
    • a magnet to check for hidden rust repairs
    • a torch to look under the bonnet
    • a friend – preferably someone with a bit of car knowledge.

Check the paperwork

Check that the car has a current warrant of fitness – vehicles for sale must have a warrant of fitness less than one month old.

However, you may buy the car 'as is where is'. Under this option you'll need to give the seller a written promise that you'll only drive the car to get a warrant. You may have to pay for repairs to bring the car up to warrant standard.

Ask the seller for any service or repair history.

If you’re buying privately, make sure you let us know straight away. 

More information about buying a vehicle

Get a professional inspection

Always insist on having a full professional inspection before buying any used car. Most garages will perform these inspections. There are also specialist pre-purchase inspection services. After the inspection both you and the seller will receive a report detailing any repairs needed.

The safety checklist

Check the exterior

Rust

Most older vehicles have some rust. Whether it's a problem depends on how much and where it is.

Look for signs of rust on the main structural supports (structural corrosion). This is dangerous. A vehicle with rust in the areas shown in the diagram will likely fail a warrant of fitness inspection and repairs will be costly.

Examples of structural corrosion points

Examples of structural corrosion points

Rust on the car body can also be a problem. Look for bubbling paintwork. It's possible that the use of a filler may be masking the problem. In some cases you can tell if this is the case by running a magnet over the car - it won't stick to the filler. However, the magnet test won't work if the filler contains iron dust.

Also look for rust:

  • on weight-bearing parts and steering wheel mountings

  • under carpets, the bootliner and in the spare tyre area

  • inside the petrol cap door.

Paint

A recent paint job could be an attempt to mask a problem. First, try the magnet test (see rust above). Also look closely for:

  • a rippled finish – this could indicate body work underneath

  • different shades of colour in different parts – check for overspray or different shades under the wheel arches and on the rubber strips around the windows.

Shock absorbers

To test for worn shock absorbers:

  • Stand at a corner of the car, push it up and down to get a rhythmic motion. Then stop. If the car doesn't stop immediately, the shocks are worn. Can't get any movement at all? The shocks definitely need replacing.

  • Repeat this test on all four corners.

  • Next, stand back to view the entire car. Does it sag to either side? To the front or back? Any sagging may result from defective springs or shock absorbers.

Tyres

Check all the tyres, including the spare. Legally, treads must be at least 1.5mm deep across 3/4 of the tread pattern around the entire tyre. However, if there are tread depth indicators the tread depth must be at least 1.5 mm in these areas.

Look for:

  • indications of tread wear on the tread wear indicator (on most tyres) in the tyre's centre groove – this shows up at 1.6mm. If you can see it, the tyre most likely needs replacing

  • uneven tyre wear – this may indicate a steering, suspension or alignment problem. Turn the steering wheel to full lock one way then the other and check the inside of each front tyre.

Panels

Open and shut all the doors, the bonnet and the boot, making sure they are aligned properly and move smoothly. Also check that the windows open and shut easily, and that they will stay open halfway.

Exhaust

An exhaust leak is dangerous – exhaust fumes getting inside your car could cause you to pass out from carbon monoxide poisoning.

To check for leaks in the muffler and exhaust system:

  • look for soft areas, brittle areas or areas where putty is used

  • protecting your hand with a rag, temporarily block the end of the exhaust pipe while the engine is running. The build-up of pressure should blow your hand away from the pipe. No real pressure? The system has a leak that needs repair.

Check the inside

Dashboard

Things to check:

  • Push, pull or twist all dashboard switches and knobs to check they work.

  • Have someone outside the car check that all lights and indicators work, including the brake lights.

  • Try the wipers, the radio, the levers for opening the boot and bonnet.

  • Can you adjust the mirrors?

Also check for old or loose wiring under the dashboard.

Seats and safety belts

Things to check:

  • The driver's seat is comfortable and you can adjust it to fit you. Look for possible damage under seat covers, if fitted.

  • All seats are properly secured to the floor.

  • All seats have safety belts.

  • The safety belts' buckle and retractor mechanisms work.

  • All belts lock up tightly when suddenly pulled.

  • The webbing is not frayed or faded - this can indicate UV damage which weakens the belt. The belt may need replacing.

Leaks

Leaks can indicate wear (especially from rust) and poor care. They can be difficult and expensive to fix.

Look for dampness or water stains on seats and carpets. If possible, lift up the carpets and check underneath, including in the boot area.

Check under the bonnet

Engine

A dirty engine can point to vehicle neglect. But a sparkling clean engine may be the result of a recent steam clean undertaken to mask defects.

Look for:

  • frayed or burnt wiring, oil streaks and poorly attached or damaged hoses

  • petrol leaks around the carburettor and fuel lines (check carefully)

  • black soupy oil – can indicate a worn-out engine

  • oil leaks or other drips under the car.

With the engine going:

  • take off the oil filler cap – if large amounts of gas come out (especially with a blue smoky tinge) the engine is badly worn (don't forget to replace the cap)

  • let the engine idle for a few minutes and have a friend watch the exhaust for blue smoke when you push the accelerator. While a single puff is okay, continuous blue smoke means a badly worn engine. (This test only works on petrol-fuelled cars.)

Radiator

Look for:

  • leaks, rust or water stains

  • leaks in the radiator hose and where the cylinder head meets the engine block.

When the engine is cool, remove the cap to check the water:

  • A little rust colour is okay.

  • A green or blue tint – from coolant or engine conditioner – is okay too.

  • Any oil in the water indicates a major problem.

  • Perfectly clear water won't tell you much – it's probably just been changed.

Don't forget to replace the cap.

Take a test drive

Before you get in the car

Check that the car is insured. You may be liable for damages if you drive an uninsured vehicle.

Pre-drive checks

Once you're in the car, switch on the ignition, but don't start the engine.

Check that:

  • warning lights go on. If they don't, there may be a fault

  • the oil and coolant level lights go off after a few seconds

  • the handbrake light goes off when the brake is released.

Any anti-lock braking system (ABS) or airbags lights (SRS) will have their own testing sequence. Check the vehicle's manual to see what this should be. Watch for any lights that stay on – especially those for brakes or coolant level.

Start the engine, with the engine cold if possible.

Check that:

  • the starter motor turns over quickly and the motor 'catches' quickly

  • there are no odd noises like backfires or a rattling exhaust

  • the oil pressure light goes off after the car has been running for a few seconds

  • there's no blue smoke coming from the exhaust. (See note under engine.)

Driving tests

While you drive:

  • listen for any odd noises that could indicate problems:

    • clanging or clunking noises when starting and stopping could mean problems with engine mountings, exhaust, suspension, transmission or the drive shaft
    • tapping or knocking noises could be from a failing rod bearing, piston or piston pin
    • grinding or whining can mean worn gears or bearings – these are expensive repairs
    • squealing noises when you brake may mean new brake pads or linings are needed.

Carpark tests

Using an empty carpark, drive at low speed on full steering lock in each direction. Rhythmic clunks from the front of the vehicle may indicate the drive shaft joints are badly worn and need replacing.

Be aware of any smells:

  • A burning oil smell may indicate that the engine is worn.

  • Petrol fumes may signal an exhaust leak. Leaks can lead to carbon monoxide getting inside the car and you could potentially pass out behind the wheel.

Test out the vehicle's acceleration:

  • When you put your foot down, does the engine pull smoothly, without any stalls or power loss?

  • When you take your foot off does the engine power down smoothly?

Hill tests

Find a hilly road that is safe for a test drive. How does the car drive up hill? This is a good time to check for blue exhaust smoke (from burning oil). Go down the hill, foot off the accelerator. At the bottom push the accelerator. If the engine is old it may take a while to accelerate and you may see a big puff of smoke from the exhaust.

Test out the vehicle's brakes. Do they:

  • respond quickly to a touch of the pedal?

  • stop the vehicle in a straight line, without pulling to either side?

Brake and gear tests

Find a quiet stretch of road and try an emergency stop, from about 30km/h. Put on the brakes firmly, but don't slam them. The car should slow down quickly and in a straight line (if the car starts to veer to one side, release the brakes and correct the steering).

Test out the vehicle's gears:

  • Can you change the gears easily and smoothly?

  • Try changing down quickly a few times - is there a crunching noise? The gearbox may need work.

  • If the car's an automatic, do the gears change smoothly? Unexpected changes or bumping noises aren't good.

  • Is the transmission oil clear red? A burnt smell indicates problems.

Final tests

Stop the car, and leave the engine running.

Check under the bonnet for:

  • smoke

  • oil or water leaks

  • problems with the cooling or electrical systems.

Find out more about features that protect you in a crash (external link)

Top