Maintenance on a Used Car

Buying a used car can be a complicated, stressful process, between choosing a vehicle that meets your needs and finding one with the features you want at the right price and in good condition.

Plus, the vehicle you’re buying may no longer be covered by its factory warranty, depending on how old it is or how many kilometres it has been driven.

Without a warranty to back you up in case something goes wrong, knowing what maintenance your vehicle needs and how often it should be done can help you avoid surprises.

By doing a little research and asking a few questions during your purchase process, you can learn a lot about what you’ll need to do to keep a used car running smoothly and reliably after you take it home.

First Things First: Consult Your Car’s Owner’s Manual

Owners Manual

In the owner’s manual, car manufacturers include a schedule to tell you how often various maintenance tasks should be done. If your used car did not come with an owner’s manual, you can often download the one for your vehicle’s year, make and model from the manufacturer’s website.

How Often Should You Change The Engine Oil And Filter?

That maintenance schedule will tell you how often to change the engine oil. If you don’t drive your car very much, change the oil once a year—even if you haven’t driven 5,000 km since your previous oil change.

The maintenance schedule will specify one oil-change interval for “normal” driving and another, shorter interval for “severe” conditions. In Canada, our cold winters qualify as severe use, so always follow the shorter recommended intervals.

Some modern cars also have an electronic engine-oil monitor that will alert you when it’s time to change the oil and perform various other maintenance procedures.

If you don’t know the last time your new-to-you used car had its engine oil changed, get it done as soon as possible after you buy the car, for your own peace of mind. And if you can’t find the maintenance schedule for your vehicle, you should change conventional oil every 5,000 km. Synthetic oil provides longer-lasting protection and doesn’t need to be changed as often.

Transmission Fluid

If your car has an automatic transmission, its fluid also needs to be changed periodically. Again, look at the manufacturer’s maintenance schedule to find out how often to do it. If you tow a trailer or regularly haul heavy cargo (in a pickup truck, for example), you’ll have to change the transmission fluid more often, since those types of driving cause the transmission to generate more heat, which can degrade the fluid and damage the transmission.

The maintenance schedule will also tell you to inspect the transmission fluid a few times a year. If the fluid smells burnt, it’s time to replace it. Check the fluid level as well, following the procedure in the owner’s manual. If the level is low, it can cause the transmission to shift poorly or not engage at all.

AWD Differential and Transfer Case Fluids

If your vehicle has all-wheel drive or four-wheel drive, the maintenance schedule may tell you to check the condition of the fluids in the transfer case and differentials, probably whenever you check the transmission fluid. As with transmission maintenance, deciding when to replace the lubricants in the AWD system depends on how you drive the vehicle. If you regularly tow or drive in challenging off-road conditions that put stress on the drive system, you’ll have to change the transfer case and differential fluids more frequently than if you only drive on paved roads.

How Often Should You Change Engine Coolant and Other Fluids?

Your car’s maintenance schedule will tell you how often to check the condition and level of the coolant that keeps the engine from overheating. It will also provide inspection and replacement intervals for other important items like power steering and brake fluid.

Brake Pads and Rotors

Rotors and Pads

There’s no set replacement interval for brake components, because how long they last depends on your driving style. City driving with lots of stop-and-go will wear out brakes sooner than highway driving. Also, using the brakes gently helps them last longer than if you wait until the last minute to slow down and then brake aggressively.

Whether you’re shopping for a used car or have been driving your vehicle for a couple of years, you can tell a lot about the condition of the brakes simply by using them. When the car is running, the pedal should yield to pressure from your foot at first but then feel firm. When driving, the car should stop with no vibrations or grinding noises. A pulsating brake pedal often means the rotors are warped, and grinding sounds mean the rotors may be pitted and scored from corrosion, or the pads may be completely worn down. You should get some advance warning of worn-out pads, as your car’s brakes have wear indicators that make a squealing sound when they touch the rotor.

If the car has drum brakes at the back wheels, you’ll have to remove the wheels and the drums to inspect the brake shoes. Drum brakes often need less frequent service than discs.

Your car’s brakes use hydraulic fluid to provide the pressure that makes them work. Low brake fluid can cause the pedal to feel soft. If the fluid is low, there could be a leak in the system.

Does the Engine Use a Timing Belt or Timing Chain?

Timing belt

Every gasoline or diesel engine has a metal timing chain or a rubber timing belt to operate the camshafts that open the intake and exhaust valves at the appropriate times. Some internet sleuthing will tell you whether the engine in a particular car uses a chain or a belt.

In a well-maintained engine, a metal timing chain should last the life of the engine.

A rubber timing belt must be replaced at regular intervals: Rubber dries out and becomes brittle with time, and regular driving slowly stretches the belt. Too much stretching can throw the engine’s timing off and affect its performance.

As a general rule, you should replace a rubber timing belt every five years or after 100,000 km of driving, whichever comes first. However, some cars require more frequent belt changes. Again, check the maintenance schedule for your car’s replacement interval. If you leave a timing belt too long, it can break, and in some engines, that can cause serious internal damage that is much more expensive to repair than having the belt replaced on time.

Does the Engine Have Direct Fuel Injection or Port Fuel Injection?

Next, a little research will also tell you whether a car has modern direct fuel injection that squirts fuel straight into the combustion chamber, or an older-style port injection system that sprays fuel into the intake tract, where it will be sucked into the cylinder.

Direct injection generally means better fuel economy and more power, but its drawback is that it can allow carbon deposits—a by-product of the combustion process—to build up on the engine’s intake valves.

Regular oil changes can help slow the buildup of these deposits, but it won’t stop the process. Over time, these deposits can reduce the engine’s performance and cause it to run poorly. Many auto repair shops can remove these deposits, and while you probably won’t have to worry about it often, it will add to your vehicle’s maintenance costs in the long run.

Port injection avoids this problem because the fuel helps clean the intake valves as it rushes past them into the cylinder.

Don’t Forget the Pre-Purchase Inspection

No matter what kind of vehicle you’re shopping for, have it inspected by a mechanic of your choosing. A thorough inspection should cost between $100 and $200, but is worth more than that in terms of peace of mind, as it can reveal problems that even a reputable dealer or private seller may not be aware of.