We don't know exactly what kind of car you have: a family car, an economical commuter car, a sweet vintage ride or a modern gas-electric hybrid. But we do know one thing: You probably put a good deal of your hard-earned money into it, and keeping it running well matters to you. Sadly, though, fewer and fewer people have good old-fashioned mechanic's skills these days. In part, it's because cars have changed -- they're more fuel-efficient, create less in the way of emissions, and need major service less frequently than they used to. However, there's no denying that they're harder to work on. Some have diagnostics systems that need to be hooked up a computer, for example. Or key parts of the engine are hidden away, where they used to be much more accessible.
Still, the basic principles of the engine -- ones that were pioneered by automotive geniuses like Karl Benz (whose last name may be familiar to you) -- remain the same. Many things you learned years ago, in auto shop or from a gearhead relative, still hold true. So, is your engine savvy still intact? Or are you a little rusty? We've devised a quiz to help you find out. (By the way, don't worry if you're a truck owner and enthusiast -- you're still welcome; the word "car" in the title is a generalization). So let's get started! No coveralls needed; just sharp wits!
Even if you hand off all repairs to a mechanic, you've almost certainly used a dipstick before. It rests in the oil pan and, when pulled out, shows you the oil level. Because it's so often used by non-mechanics, the handle is usually brightly-colored.
You've probably heard someone refer to "forty-weight" oil, talking about 10-40 or 5-40 engine oil. Some wits also refer to the black coffee in the auto shop's waiting room as "forty-weight" -- which, if you've ever had it, you'll know seems fair.
There are several filters in an engine; impurities must be removed from oil, fuel and air. Even brake fluid has a small filter in its repository to keep anything from getting in and gumming it up.
Doesn't sound like very much, does it? Surprisingly, the number of volts in the car's battery isn't much more than that which powers your household smoke alarm. This is because another auto part intensifies the charge. Which part? Funny you should ask ...
The ignition coil intensifies the voltage from about 13 to the thousands of volts that the spark plugs require. If you chose "spark plugs," they are an essential part of the car's electrical workings, igniting the fuel-air-mixture ... but they don't increase the battery's voltage.
Of course, it's the firewall. As the name suggests, it provides the car's passengers protection from the heat generated by the engine, as well as from harm in the case of an engine fire.
Carburetion is becoming a thing of the past. Fuel injection is more efficient, and became common in production cars in the 1980s. Admittedly, car buffs like carburetors -- having rebuilt one is a point of pride for amateur mechanics.
Chiefly, the oil lubricates the engine. But this also keeps engine parts from overheating (because friction), and picks up particles of dirt along the way. Of course, this last function wouldn't be of any use without the vital oil filter.
As in your home, electrical circuits in your car have fuses, and they "blow" rather than let a circuit become overloaded. If an engine part, or part of the car's accessories like the sound system abruptly stops working, check the fuse box.
Once the fuel pump stops delivering gasoline to the engine, it's over. Of course, the pump itself might not have failed, but the fuse for the circuit that powers the fuel pump might have blown, so check that first.
Technically, a fuel-air mixture is created just outside the cylinder and sprayed into it through the intake ports. We'd go into greater detail about what happens from there, but we'd be giving away the answers to future questions!
In auto engines, there are three configurations for the cylinders. "Flat" is also sometimes referred to as "boxer." while "V" is only used with engines of six cylinders or more.
Bearings are little metal parts that make larger parts run more smoothly together. In this way, they reduce friction and heat. They're so important that they're found in multiple places in an engine.
Bushings are rubber or polyurethane cushions in the suspension system, outside the engine compartment. We include them here because they're easy to confuse with "bearings."
After the mixture enters the small chamber of the cylinder, the piston comes down and compresses it. This makes for a powerful localized explosion, that sends the piston rocketing back upward, to move the crankshaft.
Coolant can come in these colors and more. It's enough to make you think that the chemists are frustrated at missing their chance to go to art school! A good rule of thumb is not to mix colors of coolants.
The thermostat in the engine has an important function: It'll tell you if the engine is overheating, as seen in a gauge on the instrument panel. It also tells the engine when the coolant needs to kick in.
The crankshaft converts the motion of the pistons, which is up-and-down, into rotational motion. Motion has to change directions several times in the workings of a car. Some of this takes place outside the engine.
Your heart has valves, as your engine does. Of course, it isn't just humans who have cardiac valves, but if we'd said just said "body part" above, you might have thought of the auto body -- hence the specific phrasing!
The four parts of an engine cycle are intake, compression, ignition and exhaust. Or, if you prefer, "suck, squeeze, bang. blow." But we feel like this was just an attempt to create a mnemonic that sounded as dirty as possible.
Poppet valves are an essential part of the ignition system, getting the fuel-air mixture through the intake ports. Fun fact: the word "poppet" is related to "puppet" -- it refers to the up-and-down motion of the valves, like a puppet on a string.
A gap gauge checks the gap between the center and side electrodes of the spark plug. If the gap is either too wide or too narrow, there can be misfirings and loss of engine efficiency.
The cylinder head encloses the block at the top, but isn't quite flush with it. It leaves rooms for the passages where exhaust escapes, or air comes in.
The "ring" in "ring job" refers to the piston rings, which seal the individual cylinders. An old-fashioned ring job is a really time-consuming task -- there's more than one per cylinder, and the gap has to be carefully calibrated with a feeler gauge. Fortunately, it's needed far less often on today's vehicles.
The very adjective "timing" implies synchronization. Not-so-fun fact: This is one of those parts which, if broken, can stop your car dead in the water. So be sure when it's replaced that your mechanic doesn't tighten it up too much.
The rule of thumb used to be between "60,000 and 90,000 miles." This has lengthened as engine craftmanship has improved. It might be worthwhile, though, to inspect it for cracks and wear starting at about the 60K point.
Several things are examined, and sometimes replaced, at the same time as this belt. They include the water pump, the idler pulleys, and the belt's tensioner. No wonder this scheduled service can run so high in its cost!
The advantage of a timing chain is that it doesn't stretch and wear out. The extra expense comes up front, as part of the car's purchase price.
A turbocharger forces exhaust fumes back into the combustion chamber. This creates greater compression in the cylinders (per Boyle's law), and therefore a "bigger bang."
The head gasket seals the entire cylinder head. Individual cylinders are sealed by piston rings.
It's true, there are three-stroke and even two-stroke engines. In the latter, the intake and compression part are combined into one movement, as are the ignition and exhaust strokes. The advantage of engines with fewer than four strokes is a subject a bit too complicated to go into here.
This is also referred to as "engine displacement." The more fuel-air mixture the cylinders can hold when the piston is at "top dead center," the more gets compressed. The more that's compressed, the more powerful the rebound.
You might be familiar with the term "bore" from firearms, in which it is the diameter of the barrel. In cylinders, the wider the bore, the more voluminous the chamber (unless it is unusually short). So, as with guns, a larger bore equals power.
The name does come from the sport of boxing, as pairs of pistons in a flat engine come together and apart like a boxer's gloves. This configuration was created by Karl Benz. who called it the "kontra" engine, again referring to the opposition of the pistons.
Diesel engines don't use a spark to ignite a fuel-air mix, but rather heat and compression. The heat is provided by the glow plugs. Cars with diesel engines used to be favored for their reliability; they are still popular in India, but because of the lower price of diesel fuel compared to regular gas.