Used Car Pre-Purchase Inspection: 10 Things to Check

Used Car Pre-Purchase Inspection: 10 Things to Check

Updated March 2019

You have to be careful when buying a used car. Things aren’t always as good as they seem, so it’s always recommended to get a mechanic to inspect the pre-owned car you’re hoping to buy.

Often called a pre-purchase inspection, many mechanics may differ on what they check and in what order, but their feedback is invaluable. Here are ten of the usual trouble spots that most mechanics will take a look at – and ones that you should make sure they do. And on top of all that, make sure that the used car you’re getting has a clear history through its paperwork and a clean title. If it has been in an accident, that might not be a deal breaker, but it is something you need to know.

Some things that the mechanic will inspect will make sense, but not everything is clear. Here’s a guide to know what your mechanic is checking (or should be checking), and why.

10: Body – Dents – Rust


Almost every car has some minor imperfections that will occur during its usual lifespan. Mechanics don’t really look for those, but instead are checking out panels that don’t line up properly, hinting at an accident or cheap repair. Paint that isn’t exactly perfect can also hint at some similar problems.

Of course, the most important thing to check on a car’s body is rust. Bulges or blisters in the paint are troubling. Mechanics will check the body, underbody and frame for rust issues.

There’s also the worry of a car that looks too good. A shiny new coat of paint, could be a method of masking rust lurking beneath.

See Also: Buyers Guide: Five Rust Inhibitors to Choose From

9. Suspension – Tires

tire-pressure-checkAnother quick thing to check is the suspension and tires. Pushing down on each corner of the car should give the mechanic plenty of information about the state the shocks are in. If it bounces once, and returns to its normal position, then it should be fine, otherwise the shocks might be shot. A test drive will help cement any suspicions about the suspension.

Tires are another important factor. Ensure they’re not leaking air, and that the spare is in good shape too. Mechanics will check them for uneven wear which will hint at alignment problems.

See Also: Top 10 Tire Pressure Gauges

8. Lights

Headlight-foggyThe obvious here is to ensure that the lights are not faded or the lenses aren’t broken. Some people might use different bulbs which can cause electrical problems, or cause heating issues. The mechanic will be able to point these out, and check the overall condition of headlight assemblies to ensure they haven’t been replaced due to a crash.

The lights can also hint at a car’s overall electrical health too if they’re dimming or flickering oddly. To get a perfect grade, all brake lights, headlights, highbeams, turn signals and interior lights have to be working properly.

See Also: Top 10 Best Headlight Restoration Kits

7. Instrument Gauges

CNo warning lights should be illuminated on the car’s instrument cluster, the car’s odometer should be working and the speedometer and tach should be reporting the correct measurements. This is something that is easy to gloss over, but could be an expensive repair if needed.

See Also: What does the light on my dash mean?

6. HVACcar air conditioner

Assuming the car has air-conditioning, it’s important to make sure it works, and works well. A mechanic will not only ensure that cold air is coming from the vents, but that the fan operates on all speeds, and that the air conditioning compressor is not too noisy. Similar checks should be performed on the heater.

5. Radiator – Hoses

Check-Radiator-Hoses-IntroThe radiator is an important place to start under the hood. If the coolant is low, or rusty looking, then it might hint at some neglect from its previous owner. Mechanics will also check the radiator fins to ensure they’re not flimsy and crumbly. Water hoses are also inspected closely to see whether they need to be replaced.

See Also: Does Head Gasket Sealer Work?

4. Oil

CAAs-Spring-Auto-Maintenance-Checklist-620x350Before dipping a dipstick anywhere, a mechanic will check for oil on the ground. If there’s some under the car, then there’s a likely oil leak. Oil levels needs to be checked and if the oil looks milky, dark or smells burnt, then you’re looking at some serious engine problems – or at the minimum an owner who didn’t change the oil often enough.

See Also: Should you use Synthetic Oil?

3. Engine – Knocking and Compression

compressionWhen the mechanic fires up the engine, he’s checking to see if it idles smoothly, and then if there’s any rattling or knocking while the engine warms up. These can hint at several problems including sensor issues, or worse, engine problems.

Knocking could also hint at poor care from the past owner, perhaps using the wrong fuel type, or abusing the engine.

A compression test is an important and easy way to see if there’s anything wrong. Using a small tool inserted into where the spark plug normally goes, one crank of the engine will reveal if the pressure in the cylinder is ideal. If it’s not, then forget everything else. This car isn’t for you.

2. Exhaust

Diesel-ExhaustWhen the car is fired up, smoke might come from the exhaust pipe. If smoke comes out of the back of the car, the reality is that the car is trying to tell you that something isn’t right. Blue, black or white smoke means that there are problems afoot – or should we say a-soot?

SEE ALSO: What Does the Smoke from My Exhaust Mean?

1. Brakes – Transmission

Disc_brake_worn-out_rotorWhen it comes to ensuring you are buying a safe car, the brakes are one of the most important things to check. Does the hand-brake or parking brake hold the car on a hill? When it comes to the test drive, the mechanic will find a safe straight piece of road to test out the brakes. The brake test will determine that the brakes have a solid feel and the car brakes in a straight line. Also be sure to listen carefully for squealing or grinding noises.

See Also: Top 8 Best Brake Rotor Replacements

GearThe mechanic will be getting a feel for the transmission during the test drive. The car should shift smoothly. Automatics shouldn’t have any delay in gear selection, and manuals shouldn’t crunch or grind when going into gear.