20 Bad Auto Habits Your Mechanic Wants You to Stop Doing

To keep your vehicle in good condition and avoid costly repairs, pay attention to warning lights and unusual noises or smells.

Warning lights on modern vehicles can indicate problems with multiple systems, so it’s important to address them promptly. Routine maintenance is also critical, as it helps to prevent issues from arising and prolongs the life of the vehicle. Unusual noises, such as squealing, screeching, grinding, rumbling, clicking or clunking, can indicate problems with the drive belt, pump, engine bearing, brakes, suspension, constant velocity joints, wheel bearings, or tires. Ignoring these noises can lead to further damage and costly repairs. Similarly, ignoring unusual smells, such as an oily burning smell, can indicate leaks that can cause damage to engine, transmission, or power steering components, and even result in a fire. Addressing warning lights, unusual noises, and smells promptly can help prevent more serious issues from arising.
Unusual smells can indicate potential problems with a vehicle, such as burning rubber from a failing drive-belt system or brakes that are not operating properly, which can result in engine damage, overheating, and accidents. Ignoring these smells can lead to higher repair bills. Therefore, a pre-purchase inspection by a professional mechanic is recommended to identify hidden issues that cannot be detected during a cursory check. This inspection involves scanning the vehicle’s computers, test driving the vehicle while monitoring computer data, performing physical checks, and testing various systems. After receiving a full report of the results and recommended repairs, the buyer can proceed with the purchase, renegotiate the price, or walk away. It is also advised to avoid brake job “specials” and drive on worn tires, as they can increase the risk of accidents and end up costing more in the long run.
Tire wear below 4/32 inches reduces traction and increases stopping distance, resulting in increased hydroplaning on wet pavement. Replacing tires at 4/32 tread depth provides extra safety margin and reduces skidding on wet pavement. Driving an overheated aluminum engine for even 5 minutes can cause total head gasket failure, leading to expensive repairs or even engine replacement. Large wet oily stains on your driveway indicate a fluid leak and low fluid levels can cause early engine, transmission and power steering failure. Bring your own auto parts online and asking the shop to install them for only the cost of labor is not recommended.
Auto repair shops, like any other retail service business, make a profit from labor and parts. When customers bring their own parts, shops may refuse to install them or charge a surcharge or higher labor rate to make up for the lost profit. Additionally, shops may not cover labor if the customer-provided part fails while under warranty. Despite common beliefs, auto repair shops’ profit margins are similar to other retail service businesses and are much lower than industries such as clothing, restaurants, furniture, and optical. Charging a diagnostic fee is necessary because diagnosing a problem requires a skilled technician to consult a database of technical service bulletins, conduct multiple tests, and use specialized equipment. Shops may charge higher fees for this service to cover specialized equipment and ongoing training. Customers who tell shops what to fix based on their own diagnosis may put shops in a difficult situation. Shop supply charges are based on an average charge to cover the cost of supplies, rather than tracking the exact price for each repair.
Some shops may include the cost of shop supplies in their hourly labor rate, which can make them appear uncompetitive compared to nearby shops that don’t. To avoid this, some shops bill separately for shop supplies, but this can result in customer complaints. Nevertheless, shop supplies are a legitimate cost directly related to vehicle repair, and customers will ultimately have to pay for them. Shop owners do not profit greatly from shop supplies charges.

Maintaining a clean car is important, as mechanics may need to access different parts of the car, and a cluttered car may cause delays. It is also important for customers to provide all necessary information about their car to mechanics, as withholding information can make diagnosing and fixing problems take longer.

Switching between reverse and drive while the car is in motion can damage the vehicle. Automatic transmission vehicles have a transmission selector switch that signals the computer to engage reverse gear, while on manual transmission vehicles, misadjusted shift linkage or damaged shift cables can prevent the reverse gear from engaging properly.

Haggling over repair prices is generally not appreciated by mechanics, as pricing reflects the time and expertise required for the job. Calling repeatedly for updates may also slow down the repair process, as mechanics are often busy working on multiple cars.

Not driving the car at all can cause problems, as the car is designed to be used regularly. If the car will be parked for an extended period, a smart charger like the Battery Tender Junior can help maintain the battery charge. Finally, it is crucial to put fluids in the correct locations in the car to avoid costly damage.