Nobody wants a lemon. Whether you are in the market for a dependable used car, or a classic to restore, it is important to thoroughly inspect a car before making a purchase.

Condition of Mechanical Components

Before looking for a used car, assess your needs. Your intentions for the car will determine what quality of condition you should look for, and what you are willing to sacrifice. For instance, if you hate working on cars or don’t know how, you’ll want a car that is mechanically sound. On the other hand, if you are handy with a wrench or looking for a project, a car needing repairs may save you some money. Before you start shopping for a car, decide how much work you are willing to put into it – and stick to your decision. You’ll save yourself from having regrets later on.

Engine

The condition of a car’s engine is one of the first and most important things to look at.

Preventative maintenance is important. Timely oil changes and the quality of oil used are important contributors to a healthy engine, so be sure to ask the seller to see records of oil changes, if available. Also, many newer cars have belt-driven engines, instead of chain-driven engines. Know what the car has, and ask for records of timing belt replacement. Most timing belts must be replaced every 60,000 – 80,000 miles to prevent worn belts from stretching or breaking. Having the timing belt replaced can be expensive, but the repairs on an engine with a broken belt are guaranteed to be many times more expensive, so it is important to know when the belt was last replaced.

Unless you are very adventurous, buying a car that needs a lot of engine work is probably not a feasible option. There are a number of things to look for in order to determine the condition of a car’s engine. An engine that is covered with lots of black, sticky-looking dirt may have a serious oil leak. Black or bluish smoke coming from the tailpipe indicates that the engine is burning oil, most likely from worn piston rings, a problem which allows oil to slip by the piston and into the combustion chamber. White smoke coming from the tailpipe means that the engine is burning coolant, and is generally an indication of a blown head gasket. It is also a good idea to pay attention to how the engine sounds: a rhythmic ticking coming from the top side of the engine may indicate that the valve clearances need to be readjusted, while a knocking sound coming from deeper inside the engine can be a sign of serious internal damage.

(A note on rotary engines: Rotary engines operate on the same basic principle as the four-stroke engines in most passenger cars; however, because they are set up differently, they have different problems and different symptoms. Rotary engines commonly have problems with oil passages and seals, so it is important to look for signs of oil burning before purchasing a car with a rotary engine. Also, be aware that rotary engines are not high mileage engines; it is not uncommon to find these cars with the engines replaced or rebuilt after about 100,000 miles.)

Drive Train

A car’s drive train is another important factor in choosing a classic or used car. When test driving the car, listen for grinding or whining noises coming from the transmission. Ensure that automatic transmissions shift properly and at the right moment. With a standard transmission, the best way to check for a worn or slipping clutch is to attempt to accelerate in fifth gear at about 2000 RPM; if the engine accelerates quickly but the speed of the car is unaffected, the clutch plate will need to be replaced, which can be a major undertaking. Also, be sure that the clutch pedal feels as though it is adjusted correctly. In rear wheel drive cars, a worn differential (located in the rear of the car) will make clunking or grinding sounds in a right- or left-hand turn, and worn U joints (located in the middle and the rear of the car) will clunk or vibrate when under load, such as when you take your foot off the accelerator and allow the engine drag to slow the car; in front wheel drive cars, worn CV joints (located in the front of a car) will make clunking or grinding sounds. It is a good idea to ask when the transmission was last serviced; generally, automatic transmissions should have the fluid and filter replaced at least once a year, and manual transmissions should have the oil changed at least every two years.

Braking System

One of the next biggest areas of regular maintenance is the braking system. Front brakes will need to be replaced much more frequently than rear brakes. Most cars have disc brakes on the front wheels and drum brakes on the rear, since the front brakes handle approximately 75% of the force it takes to slow or stop the car. However, many newer cars have disc brakes on all four wheels, just as some older cars have drum brakes on all four wheels.

When inspecting the brakes, look for abnormal wear, such as deep or jagged grooves in the disc or drum surface, or pads/shoes that are unevenly worn on each side. Also, check the hydraulic lines for evidence of leaks. It may be helpful to ask the seller for records of break maintenance.

Fuel Delivery and Emissions Systems

Whether a car is carbureted or fuel injected, problems with the fuel delivery system can be a nightmare. Watch for strong-smelling exhaust, which can indicate a rich air-fuel mixture; a smell of raw gasoline around the engine bay may mean a bad carbon canister, a dirty canister filter, or a leak in the vacuum lines that operate the canister. Although the sniff test can detect most serious problems, an emissions test is generally a good way to highlight more subtle problems with the fuel delivery and emissions systems. A fouled oxygen sensor, a malfunctioning EGR valve, and a bad catalytic converter, among other things, can cause poor readings on an emissions test. Additionally, ask the seller for records of any maintenance, including carburetor tune up or replacement, fuel pump replacement, and fuel filter replacement.

Cooling System

A well-maintained cooling system will be less likely to have problems, so again, ask the seller for information regarding maintenance. Antifreeze needs to be changed every couple of years, and most systems will benefit from regular flushing. In hotter regions, people often run cars with water instead of an antifreeze mixture, but these cars will have more corrosion in the cooling system. When test-driving the car, keep a close eye on the water temperature gauge, to be sure that the car runs at a steady temperature. After driving the car, be sure that the radiator has heated evenly; cold spots on the radiator may indicate blocked tubes, which will need to be rodded out at a radiator shop. Also, check the hoses, making sure they feel firm; overly stiff hoses are liable to split, and spongy or bulging rubber warn of weak spots that could burst at any moment. Make sure that the bearing on the water pump is not noisy, that the drive belt has about a ½” of deflection when you press down on it, and that the cooling fan is working. Also, check for obvious leaks around the system.

Ignition and Charging Systems

A quick visual inspection can satisfy most doubts about the ignition system. Trace all of the spark plug wires and ensure that they are free of corrosion and fit tightly on the ends of the spark plugs. If the engine has a rough, loping sound to it, you can check for arcing by running the car in a darkened garage. If tiny arcs are visible along the plug wires, the current is not reaching the spark plug, and the plug wires need to be replaced. Check the battery and cables for abnormal amounts corrosion. If you own a voltage meter, you can test the battery and the alternator. When the car is off, the battery should read between 12 and 13 volts; while the car is running, if the alternator is working properly the reading should be around 14 volts, and should remain steady at different engine speeds. Also, check that the key fits snugly and turns smoothly in the ignition lock cylinder, and that the car starts without much effort.

Suspension System

The most frequently replaced components of a car’s suspension system are the shock absorbers or struts. (Many trucks and older cars have shocks, while newer passenger cars tend to have struts. The main difference is that struts usually bolt directly to the car at the top, while shocks are attached to ball joints at both ends. Both shocks and struts do essentially the same job.) To check the condition of the shocks, use your weight to bounce the back end of the car up and down several times. When you stop bouncing, the car should settle after only one or two more bounces on its own. Use the same method to check the front shocks. You can also visually inspect the shocks or struts for signs of leaking hydraulic fluid. If the car bounces more than a couple of times once you let go, or if there are signs of leakage, the shocks or struts will need to be replaced.

Another thing to look for is evidence of a bad alignment. If the tires show abnormal wear, it is best to have the alignment checked, to be sure that the culprit isn’t worn suspension components.

Condition of Exterior

For those seeking a cheap-yet-reliable set of wheels, the condition of the exterior of a car may not be as important as its mechanical condition. However, for those who want to restore a classic, the condition of the exterior may be the most important factor in buying a car, as exterior parts for older cars are becoming increasingly harder to find.

Tires

The condition of the tires is important for the amount of life you will get out of them, but also because certain wear can tell you about the condition of the car’s suspension system. Look at the tires closely; excessive wear and balding on just one side of the tread indicates a problem with the alignment. However, not all abnormal tire wear may indicate problems with the suspension. Excessive wear on both sides of the tread can mean prolonged under-inflation of the tires; excessive wear down the middle of the tread can indicate prolonged over-inflation. The best way to be sure is to have the alignment checked if you notice any abnormal wear in the tires; some shops will do this as a courtesy, while others will charge you a nominal fee that will be deducted from the price of a re-alignment if you decide to have it done there.

Body

When it comes to inspecting the body of the car, your needs will depend heavily on your intentions for the car. If you are looking primarily for a car that is mechanically sound, body damage might not detract from a car that runs well, and may even help you get it for a better price. However, if you are looking for a classic to restore, a sound body may be more important to you. Other than the obvious exterior damage, such as dents and rust, look for subtle ripples or curves that don’t flow with the lines of the car; this may indicate damage that has been repaired in the past. If are looking for a car that does not need to be repainted, be sure to inspect the paint thoroughly, looking for signs of a cheap paint job (cracking, peeling, fading, and the rough finish known as “orange peel”).

Rust: The Car Cancer

When it comes to the structural integrity of a car, rust is perhaps the most serious issue. Rust can work from the inside out, coming as a complete surprise; to avoid being disappointed with a car that you thought was structurally sound, be sure to closely inspect it for rust. Look for bubbling in the paint, a sign that the metal underneath is rusting. Also check the undercarriage. Rubberized undercoating can protect a car from the corroding effects of road salt and weather, but it can also temporarily disguise a case of cancer, so be suspicious of undercoating that looks too fresh.

Interior

The condition of the interior is perhaps the least important factor in choosing a car, but it is still important to know what it is that you are purchasing. Those wanting reliability over looks can be easily satisfied with a pair of seat covers over worn upholstery, floor mats over dirty carpet, or other cosmetic cover-ups. However, for the collector, condition of the interior can be important in its own right, if only to weigh the total amount of restoration needed.

Electrical Wiring

It is not uncommon for older cars to develop problems with wiring, switches, or relays. Be sure that all of the exterior and interior lights work properly. Also check other electrical components, such as the cigarette lighter and rear window defroster.

Climate Control

Although it may seem like mere creature comforts, it is still important to ensure that the climate control in a car is functional. With the car running at operating temperature, turn the heater on full and make sure that the vents blow hot air. Also make sure there are no signs of antifreeze leaking from beneath the dashboard; antifreeze in the interior indicates problems with the heater core and/or heater hoses, which can be a time-consuming and expensive repair to make. If the car has air conditioning, turn it on and ensure that the air becomes cool; it is also a good idea to stand outside the car while the air conditioner is on and listen for growling, grinding, or other abnormal noises.

Safety Features

For the safety of you and your passengers, it is important to make sure safety features such as seatbelts and air bags appear to be functioning properly. Federal and state laws protect owners of newer cars from defective safety features; if you have a concern, check with the car manufacturer’s local dealerships to find out if the car is eligible for free repair.

Cosmetics and Miscellaneous

The condition of the rest of the interior is primarily personal preference. Whether or not you are willing to tolerate cracks in the dash, rips in the upholstery, or a broken radio is entirely your decision. It is always nice to find a car that is in good condition cosmetically as well as mechanically, but don’t let yourself be so dazzled by a beautiful car that you forget to inspect it thoroughly; you’ll be happier in the long run if you make sure you satisfy your own unique needs.