How Well Do You Know the Basics of Auto Mechanics?


By: Steven Symes

7 Min Quiz

Image: shutterstock

About This Quiz

Do you really think a car just needs to have gas put in it and that's it? Or are you a mechanical guru who can climb all over in an engine compartment and fix whatever is wrong? Many people just take their car to the mechanic and do whatever they're told is necessary. They might complain about the cost, but they figure the mechanic knows best. Maybe you're not that type of an individual. 

Knowing the basics of auto mechanics doesn't mean you can rebuild a transmission or an engine, or that you can fix any wiring issue that crops up. It does mean you can successfully manage common problems, especially basic maintenance. Another key is knowing when you're in over your head and need to recruit the help of a professional mechanic. After all, some problems, and even regular maintenance, need the touch of someone with advanced training, expensive tools, and extensive experience. There should be no shame in relying on a technician for those issues. 

Can you manage the basics of auto mechanics? Take the quiz to find out now! 

When you need to jump a car, to which car do you hook only one cable to the battery?

Most people don't remember how to correctly hook up jumper cables, which is why some have a card attached showing the proper layout. You should always ground the negative cable on the car being jumped, instead of hooking it up to the battery, otherwise you might fry the electronics or the battery could explode.


If the exhaust system on a car starts scraping against the road, what's the most likely cause?

Car exhaust systems are kept suspended under the chassis by rubber hangers, which over time will wear out to the point the system droops. Replacing them is a cheap and simple process that pretty much anyone can do.


If a car's tires have more wear on the outer edges of the tread, what is the likely problem?

Following the recommended air inflation made by the vehicle manufacturer, not what's printed on the tire sidewall, will ensure more even wear. If you over-inflate the tires, the tread will wear out in the middle faster.


If your car's heater was working fine one day and the next is blowing only cold air, what should you check first?

The heater in cars is actually powered by the heat shed from the engine through the cooling system. That might sound odd, but as the coolant leaves the engine, some of it makes a pit stop in the central heating core. Shaped like a mini radiator, this channels hot air to the cabin, so you can stay warm.


If you're using a tire iron, when should you first loosen the lug nuts on a wheel?

If you're not fortunate enough to have air tools, using a tire iron can really make a car rock back and forth. In case you aren't aware, jacks won't hold the vehicle up under that kind of movement, so it's best to loosen the lug nuts slightly, then raise the car and take them off the rest of the way.


When should you check radiator hoses for signs of failure?

Since you should squeeze the hoses to check that they're not brittle or cracking, this job is something best done with the engine cold. Otherwise, you risk having hot coolant come gushing out, leaving you with severe burns.


What fairly common tool helps you turn bolts to spec on a car?

A torque wrench can accurately measure just how much twisting force has been placed on a bolt, which is something vehicle manufacturers specify. Not following those figures could lead to loose bolts and all kinds of problems for your car, so follow them precisely.


Instead of waiting for the warning strip to make that annoying squeal, what can you do to tell how much life is left in brake pads?

You can pick up a brake lining thickness gauge from most automotive parts stores in person or online. It comes with a variety of metal strips, each one representing a measurement of how thick your pads are. Using this will give you a more realistic idea of how far the pads on your car have worn down.


On what part of a car should you jack it up?

Every car has at least four designated jack points, which are often marked conveniently with notches. If you aren't sure where they are, check the owner's manual, since jacking the car up anywhere else might lead to serious damage or safety issues.


What will prevent a fresh oil filter from fusing to the vehicle?

When you do an oil change on your car, always remember to spread a fresh coat of oil around the new filter's rim. It will keep the gasket from cracking and leaking, as well as prevent the filter from fusing, which leads to an expensive and unnecessary repair.


Before you install new spark plugs in your engine, you need to first check for what?

When spark plugs are shipped, they're already gapped. But the manufacturers can't possibly ensure they're gapped to your engine's specification, considering the same spark plug might be compatible with dozens of other engines. Instead, get a gap tool and check it yourself before installing the spark plugs.


How do you know what weight oil to use in your engine?

All vehicle owner's manuals have information about what oil viscosity you should use. Some even feature a chart that shows which type is best for different ambient temperature ranges. Always follow this information precisely, since using the wrong oil could have serious consequences.


When loosening a bolt or screw anywhere on a car, which direction do you turn it?

Shade tree mechanics of all stripes should know the saying "righty tighty, lefty loosey" before they ever pick up a wrench or screwdriver. Of course, if you're reaching underneath something and the bolt is pointed down, remember you turn it left as if you were looking straight at the bolt head.


Why do modern headlights get that haze on the lenses over time?

As your car's headlights are exposed to the sun's UV rays, the plastic will oxidize. It's a slow process, so you might not notice much of anything, until one day your headlights are really dim. Kits sold at stores will strip away a thin layer of the headlight surface, removing that oxidization and restoring the headlights to their original clarity.


If you're jacking up only one end of your car and are concerned about the other wheels rolling, what should you use?

As you jack up one end of a car, the wheels could roll even slightly, causing the car to come off the jack and maybe even jack stands. That's a tremendous risk, so placing wheel chocks behind the other wheels is a cheap and very important safety measure you should take.


If you're concerned about scratching up the fenders as you work in the engine compartment, which of the following items could you use?

Wrenches, screwdrivers, or even a tool belt, could rub against your car's pristine fenders, scratching the paint as you work on the engine. There's a whole range of fender covers, including some that are emblazoned with your vehicle's logo so you can show plenty of pride while you're working.


To prevent hard starts, which part of your car's battery do you need to keep especially clean?

The terminals are how electricity flows into and out of the battery, but corrosion or grime of any kind can really mess with that. To keep the posts clean, you can use a little wire brush, or even better, a battery terminal brush that quickly cleans the entire post.


If your car's exhaust is white, even after the engine reaches its operating temperature, what is the likely cause?

Whether it's from a blow head gasket, warped cylinder head, crack engine block, etc. this issue comes from coolant to one degree or another getting burned in the combustion chambers, which creates the white smoke.


Other than their being worn, what else will cause wiper blades to leave streaks on a windshield or back window?

As your car sits out in the open, the glass surfaces get dirty. When you swipe your windows with the wiper blades, the dirt and other debris accumulate​. Once the blades become dirty enough, they will start leaving trails of the debris on the glass. Cleaning the blades with a soft cloth will eliminate the problem.


What will happen if you leave a car's gas cap loose and then start driving?

The dreaded check engine light can be triggered by a loose gas cap, or one that doesn't seal properly anymore. It's a measure to keep down emissions from evaporating gas in the tank, which also lowers your car's efficiency and wastes your money.


Which of the following isn't a possible sign of a failing alternator?

The alternator on your car works as a power generator, and it's belt-driven. That means as you drive, the alternator runs and powers everything electrical in the car. It even recharges the battery, so hard starts are another possible symptom.


What tool should you use to check tire tread depth?

Automotive shops and tire stores use tire tread depth gauges constantly, since they provide a completely accurate reading about how much tread is left on a tire. Using one is simple and straightforward, and the gauges cost very little.


To see if a belt is properly adjusted on your engine, what can you use?

You can measure belt deflection or movement using two rulers as well. If a belt is too loose or it moves excessively, it could slip off the pulleys and cause all kinds of problems, including serious damage in an interference engine.


Which of the following is not a good way to loosen a stuck bolt on your car?

A stuck bolt can be one of the most frustrating things to deal with. Sometimes you need to try multiple things to loosen it, including carefully applying some heat. If all else fails, you can use a tap and die kit to remove the bolt, but you'll need a replacement.


If you drive on dirt roads regularly, which should you do more often?

You might not have a choice but to drive on dirt roads, but it's much harder on your car than driving on pavement. Not only will the air filter become clogged faster, the oil needs to be changed more often, and the uneven terrain will wear out suspension components like the shocks more often.


Before you remove the cap on a radiator, what should you check first?

When the radiator is full of hot coolant, opening the cap can cause it to spray out violently. That would result in serious burns to whoever is opening the cap, so it's really not a good idea. Always check that the engine temperature is not the least bit hot, then open the cap slowly.


To prevent damage to a spark plug when installing or removing it, what should you use?

If you look at a spark plug, it has threads and a bolt head-like area. You need a spark plug socket to loosen or tighten it. These sockets have a soft rubber inside that won't damage the spark plug diode.


What does it mean when a car is toe-in?

Toe is an alignment term that refers to how the front wheels on a car line up with an imaginary line that runs down the middle of the vehicle. Toe-in means the wheels point toward it, and toe-out means they point away from it.


Which of the following is a sign your brake pads likely need to be switched out?

Under normal operation, the brakes on your car usually don't squeal. There are exceptions, but it's best to have the pads tested to see if they're overly worn when you hear this. Even better, have a brake liner thickness gauge on hand so you can measure them yourself.


How would you test whether the coolant in your car needs to be changed out or not?

An antifreeze tester is relatively inexpensive, and it takes the guesswork out of determining if the coolant in your car needs to be flushed or not. After all, you don't want to be in the middle of nowhere with an overheating engine, or stranded in a parking lot with a frozen engine, to find out the coolant is no longer performing as it should.


Besides having them rotated, what else should you have professionals do with your tires regularly?

The tires on your car can become imbalanced for a number of reasons, even if they were balanced before. That's why you need to have them checked each time you have them rotated, and have adjustments made. Otherwise, your tires can wear unevenly.


When you park and leave your car, what should you always make sure is set?

Contrary to popular belief, the emergency brake should not be pulled in emergencies. Instead, it's really to keep the car from moving when it's parked. This is especially important when you leave your car on any kind of a hill, because it could roll away and hit someone or something.


What does a strut boot do primarily?

A strut boot keeps things like salt, dirt, sand, and other debris from contacting certain parts of the strut, like the polished shaft, bushing, and upper seal. Those elements can do serious damage to any strut, making it necessary to replace the strut sooner.


What's the best way to check that your vehicle is properly aligned?

Our eyes can't tell if a car is properly aligned, and factors like a slight slope, bumps, etc. make testing it on the road an imperfect method. Only with professional tools can anyone be sure if a car's alignment is precise or not.


What should you do if the oil pressure light comes on when your car is running?

The oil light is an indication that oil pressure has suddenly dropped below acceptable levels. If that's the case, certain parts of the engine could be not getting enough oil, which could lead to those components seizing suddenly. That's why it's best to stop the engine immediately, check the oil level, refill it if necessary, and then figure out why the oil level dropped so drastically.


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