Main Page | Recent changes | View source | Page history

Printable version | Disclaimers | Privacy policy

Not logged in
Log in | Help

Pre-Purchase Examination

From OCAU Wiki

Things to look for when buying a second-hand car (copied from this thread):

  • Rust under anything that can trap water.
  • Washed engines to cover oil leaks.
  • Wound back odometer made noticeable by a worn interior - eg worn gearknob, brake/clutch/accelerator pedals.
  • Uneven paint, or overspray on rubbers.
  • Test drive at 120km/h to check if the car wobbles.
  • Before driving, remove radiator cap and check for oily residue. This is a sign that there is most likely an oil leak in the engine.
  • Air conditioning - drive hard with air conditioning on and make sure the cooling system works properly.
  • Find someone with the same car if possible and get them to have a drive of the car to compare handling performance.
  • Make sure gearbox is not noisy and selects gears properly.
  • If the oil looks like a caramel milkshake - to quote Steve "Stay the fuck away from that car!"
  • Cheap stuff like retreads to indicate how the car was looked after.
  • Have someone watch the exhaust pipe when the car is first started. If it blows a bit of blue smoke, then there's an oil leak. Also check for excessive water coming out as this can show a head gasket or head crack.
  • If there's no book for the car, be even more wary. Lack of a book could mean that they're hiding something - lack of services, or even something large done in a service which they don't want you knowing about.
  • Have a good walk around the car and see if all the side panelling and bumpers are correctly aligned and level. If there appears to be even a very slight misalignment in the panelling, it suggests the car may have been involved in an accident. (Eg: on VR/VS Commodores, a gap of about 5mm or more is visible between the top of the rear tail light and the boot lid lip. This is from the rear chasis rails bending as a result of rear impact.) Open the bonnet and check the front chassis rails for any bends etc, they should be perfectly straight.
  • Cover a magnet in cloth and walk around the car, gently running it along the sides and especially the corners, keep an eye out for any places were the magnet stops 'grabbing' at the car. What you're checking for is body filler in case there's been an accident.
  • Make sure you check the car out in a clear sunny day, because it is easier to spot problems in 'hard to see' places. However checking on a wet day can show any leaks in the seals (front/rear windscreens, doors, tailgate, boot lid etc). It can also show you if any water is getting into any electrics. If the car has a musty smell or smells strongly of air freshener (some people use vinigar) then this can be a sign of a cover up of the 'wet smell'. If you check it on a wet day or not long after a wet day, feel under the doors to see if they are wet. If so then water is getting in between the window and the seal. This can rust the door out.
  • Take a friend with you, the more eyes the better. Get a friend to be the 'silent type'. Always have them stand away from you so that the seller cant keep you both distracted. Get the other person to look at everything (even if they dont know what they are looking at) and occasionally look unhappy with something, then look at the seller to see what kind of reaction you get. If the seller looks worried then there is more than likely something being hidden.
  • See if it idles properly (especially when its a small car with air conditioning). Put the air con on max and leave the engine running without stepping on the accdelerator. On top of that put the headlights and high beams on along with pressing the brake. This puts the engine and electrical system under a higher load. Check to see if it stalls (or comes close to it). The engine should strain a little but not to much. Also with all the electrics on the headlights may dim a little. If they dim to much then it shows that there is not enough current in the system which can show either bad wiring or possibly (and more than likely) the alternator is on its way out.
  • Check the engine and chassis numbers against what the registration papers have on them. Contact the appropriate Transport Department for your state and have the rego number checked out.
  • Check what you can see of the chassis rail in the engine bay. It might of been pranged and repaired nice on the outside but strechmarks or dents on the rails give you a clue.
  • Use a tape measure from the front wheel to the rear wheel centers and check the measurements against the factory specifications. If you can not find those specs, measure each side and check the difference in distances. Anymore than about 1-2mm(??) and you will end up with 'crabbing', which is when the rear of the car steps out when driving (the car is driving straight but the rear is shifted to the left/right). This will cause a lot of tyre wear among other things.
  • Check under the car for dents to see if its been bush bashing and hit a few rocks.
  • With the car running, take off the crankcase breather hose (goes from rocker cover to air inlet pipe). The car should breathe ie. light blow and suck. If there is no suck this hints that motor is worn (handy because this happens before it starts smoking). Note some motors naturally blow more than suck but as a general rule you should feel a tiny suction at least.
  • For front-wheel drive cars, check the CV joints by turn steering full lock and accelerating lightly in reverse. Bad CV joints will make a knocking sound.
  • See how dirty the air filter is. Ifs its a littel dirty then this is no cause for alarm. If its putrid then it shows lack of maintenance.
  • Check condition of the radiator. Check for corrosion or bent fins. To many bent fins reduces the radiators ability to transfer heat.
  • Check coolant level of radiator. Check for any brown discolouration. This is normal in older cars but to much shows higher levels of corrosion. Newer cars mostly use alloy in the heads and engine block. Alloy does not rust hence there should be minimal 'browning' of the water.
  • Run the car without the radiator cap and see if any air bubbles appears. This will tell you if the exhaust is leaking into coolant system, if it does then it usaully indicates a blown HG or head corrosion. Also note if the water starts to over flow. Especially in newer cars if it doesnt then this shows a lack of cooling system pressure. Check for leaks around and under the engine.
  • Remove the sump plug and see if theres any metal shavings stuck to it. The amount of metal shavings or particles is an indication of age and wear and tear. NOTE: To do this the sumnp needs to be drained and hence is not really an ideal pre-purchase inspection idea. However it is a good thing to check when its getting serviced.
  • Do a visual inspection of the universal joints of the tail shaft(s) and steering as these can be costly to replace. Check for excess wear also for excess slack.
  • Check that the hatch/bonnet/boot opens and will stay up.
  • Do a fairly heavy brake test. What you are looking for is a responsive braking system. Repeat this test staionary when on a hill. Let the car roll for 30cm then apply the brakes and then repeat. If you can get a "bunny hopping" effect then this is good. Check how far the pedal travels. If it travels to far then this can show a leak or air in the lines (especially with engine off). If there is a 'squishy' sound then braking (easier to hear with engine off) then this is most likely air in the line. Whilst air does generally work its way out it will decrease braking performance. After running the car turn the engine off and press the brake hard several times. The pedal should harden after a couple of pushes. If not (or it takes more than 2 or 3 hard pushes) then this can indicate a worn brake master cylinder.
  • When taking off slowly keep notice in case theres a very minor jolt. Watch for the same thing when stopping. This generally indicates worn universal joints in the tail shaft(s). Jolting between gears in an automatic can show low fluid levels of that the bands need tightening.
  • Check to see that there is no slop in the steering. Either do this when driving or when stopped. Turn the steering wheel and see if the wheels move at the same time. Slop in the steering would suggest steering shaft universal joint wear.
  • Make sure it runs alright under different speeds/revs. Dont be afraid to sink the boot in and give it a little bit of a hard time.
  • After taking it for a test drive, stick your head under the car and see if you can smell any burning oil or other bad smell. This will tell you if its leaking oil.
  • If its a 4WD car, make sure you engage 4WD to make sure the transfer case and the front diff are ok (making sure you lock the hub locks first. Naturally AWD do not have hub locks.). Check for leaks around the swivel hubs (big round bit the hubs 'swivel' on) also check if its a milky colour. Most swivel hubs will leak a little and can attract dust and oil especially if it has been used off road a fair bit.
  • If it's a manual, take it for a drive to a steep hill and get as far as you can up the hill in fourth/fifth gear. If the clutch is worn it will slip and the engine will start to rev without picking up speed, if the clutch isn't worn the car will try to stall. If its hard to get into gear (esp when down gearing) this can show worn a worn synchro mesh (or more than one if it does it for more than one gear).
  • Check the wheel bearings on the front. Jack the car up and with your hands either side of the wheel move it around and feel if there is any play in them primarily if you hold top and bottom and move on the horizontal axis. Some movement in the vertical axis is normal. What you are looking for is a clunking. Cars with power steering will show some play but if there is a clunky feel then the bearing could be on their way.
  • A good indication that there are oil leaks is a THICK build up of dirt/grime, dust/dirt loves sticking to oil. Also a good indication that shockers are worn if theres a large amount of dust/grime around them. Push each corner of the car and see how many times it bounces. If it seems to bounce for a long time then it needs new shocker absorbers.
  • Take the back wheels off and check for fluid leaking from the cylinders (assuming drum brakes). This is an automatic Road Worthy Certification failure.
  • Whilst driving in the rain can mask sqeeks, it is also useful for checking for water leaks. Though a drive in the dry will often show more potential problems.
  • Check the floors for rust.
  • Try and find common areas of rust for the type of car you are looking at. That way you know where to look. Generally rust prone areas are bottom of doors, around the front and back windows, right up in the back of the front guards where the tyres throw up dirt that gets wet and never drys. Also check spare wheel well for water pooling up or rust thus indicating a leaking boot seal.
  • Check the spare tyre, and check that each axle has the same tread. If the tread is different on each axle it may indicate a tightarse who buys 3 tyres at a time or they may have had an irreparable flat somehow. If the 2 front match each other and the 2 rear match each other then thats usually fine (if for example the 2 fronts are different tread then this is considered unroadworthy). Many people have a preference for front tyres as opposed to rear. If in doubt then ask why this was done. Check for uneven wear, on the front tyres if they are wearing more on the either edge then this can indicate a need for camber adjustment (front end alignment will fix this). If there is more wear on the middle, then the tyres have been constantly over inflated. If the wear is on both outer edges then the tyres could have been constantly under inflated or they were originally only worn on one side and have been rotated.
  • If the seatbelts, the orange buttons in the buckles and the orange speedo needle are faded you know it has spent a lot of time in the sun and possibly storms.
  • Check for hail damage. This can be hard to see sometimes. Tell-tale sign is usually on the chrome bits around the windows. Dings show up more in the shiny trim.
  • If a car is generally parked under a tree the paint is usually shithouse and has that oxidised look about it.
  • On the older auto cars, check the auto fluid colour, should be a light red, if its a burnt red (with a funny smell) it indicates that it needs flushing. On older cars this can also point to a dodgy transmission if it's never been flushed.
  • Check that the digits on the odometer more or less line up. If they are crooked, then that's usually due to a rollback.
  • While test driving, check that the odometer and trip counter are working and ticking over. If they arent then the kilometres shown on the odometer aren't correct.
  • If possible try and inspect more than one of the same model. If in doubt of something take a picture of it and compare to another of the same model.

More Links

[Main Page]
OCAU Forums
PC Database

Main Page
Recent changes
Random page
All pages

View source
Discuss this page
Page history
What links here
Related changes

Special pages