Cars are getting smarter and smarter. Mine can now beat me at chess. Just a couple of decades ago, cars required more frequent servicing to keep them in good running condition. Ignition systems were tuned up every six months to a year. Fuel and air filters were replaced as often. On the other side of the issue, emission-control devices were simple. Today’s cars are more complex but need less frequent service. It’s a trade-off. Whether your car is 2 or 2S years old, some parts and fluids need replacement. You can do the replacement yourself, as you’ll learn in this article. These parts include some filters, spark plugs, ignition wiring and parts, and emission-control components. Fluids include transmission, differential, and wheel-bearing lubricants. Even if you don’t replace them yourself, you can learn more about what they are and how to make sure you get your money’s worth from someone who does replace them.
It’s pop (or mom, if you like) quiz time!
What does the acronym H-U-B stand for in this Website?
Hints: H means under the hood, U designates adjustments done under the car, and B notes adjustments made beside the car.
Did you pass the quiz?
So grab your car care toolbox and let’s get torquing.
Replacing Radiator Coolant, Cap, and Hoses
Your car’s radiator uses more than just water to keep your engine from overheating. It uses a mixture of water and antifreeze fluid, also known as coolant. An antirust ingredient in the antifreeze attempts to minimize the rust that’s a byproduct of contact between water, air, and some metals. It’s not totally successful, however, so every year or two, you should transfuse the rust-laden coolant in your car’s radiator. At the same time, consider replacing the radiator cap and hoses on your car. These components also break down with use and can fail when you most need them-like when you’re crossing Death Valley, or when you’re already late for a job interview.
To replace the radiator coolant, cap, and hoses in your car, follow these steps:
- Remove the radiator cap and drain coolant from the cooling system. On most cars, this means placing a 2- to 5-gallon open container under the radiator and opening the drain fitting or removing the lower hose on the radiator. Some engines also have one or two coolant drain plugs on the engine block that must be removed to drain coolant from the block. Drain the coolant reservoir if possible. Your car’s heater might also have a drain plug. In each case, make sure you have a container to capture the draining coolant.
- Flush the radiator system using fresh water and a radiator cleaner. You can purchase a radiator flush system at most auto parts retailers. It includes a cleaner as well as a plastic T-fitting that you install in a system hose. You then attach a garden hose to circulate fresh water through the system under pressure. Follow manufacturer’s instructions rather than mine.
- Check the condition of the radiator hoses by squeezing them. Replace them if they are soft, have cuts in them, or give you an unexpected shower. In fact, it’s relatively cheap insurance to replace the hoses as you replace the coolant. Hoses usually cost less when replacing them isn’t an emergency. Inspect and, if necessary, replace the hose clamps at the same time.
- Replace the coolant. Recommended coolant is half water and half antifreeze fluid available from auto parts retailers. Make sure all drain plugs are tightened or replaced. Before adding the coolant to the radiator or reservoir, first open the car’s heater temperature control to the maximum heat position so that the coolant also fills the heater core.
- When you think the radiator or reservoir is full of coolant, start the car and let it warm up with the radiator cap off. The water pump inside the engine circulates the coolant, forcing air out of the system. When the upper radiator hose is warm to the touch, turn off the engine and let it cool. Then add more coolant as needed to fill the radiator or reservoir.
- Replace the radiator pressure cap with a new one. Otherwise, it will fail 75 miles from town and you will have to purchase a new one at]oe’s Hi-Way Robbery and Expensive Fuel and Auto Parts Station.
- Start the engine again and let it warm up. As it does, inspect the radiator, reservoir, hoses, engine block drain plugs, and heater core for leaks.
- Properly dispose of the old coolant (down a storm drain is a big no-no!). Seal it in a plastic container and take it to your local recycling center for disposal. Coolant is both sweet and poisonous to pets, so clean up any spills thoroughly.
Replacing the Fuel Filter
It’s science lesson time. Gasoline is processed petroleum. During the processing, contaminants are removed. However, gas is then stored in imperfect tanks with rust and bits of metal or plastic. The worst culprit is your own car’s gas tank, where contaminants can build up on the bottom. If the engine is operated when the tank is almost empty, these contaminants can be pumped to your engine along with the gas. They then can enter the carburetor or fuel injectors and block operation. Fortunately, today’s cars have filters in the fuel line to stop the big chunks from entering the carburetor or fuel injectors. Even older cars (like my 40-year-old Lincoln) have been retrofitted with fuel filters to minimize big chunks in the carburetors. Replacing the fuel filter on most cars is a piece of cake. So get out the cake server and…
To replace the fuel filter on your car, follow these steps:
- Find the fuel filter. First, check your car’s owner’s manual or service manual for the location of the fuel filter. On some cars, it’s under the hood-a small aluminum barrel in the fuel line between the fuel pump and the carburetor. On other cars, it’s a plastic-cased filter installed on the carburetor, near the fuel-injection unit, or on the fuel pump. Some are installed near the fuel tank. A few cars have two fuel filters-one near the tank and one near the carburetor.
- Remove the fuel filter. In-line fuel filters can be removed by hand by carefully loosening clamps at each end of the filter unit and then pulling the fuel lines off the filter. Fuel filters installed on the carburetor or fuel pump require that you use a wrench to first loosen the fuel line and then remove the filter.
- Replace the fuel filter. You can find a replacement fuel filter at your favorite auto parts store or many hardware stores. There probably will be a brand name and a parts number on the filter. If not, an auto parts counterperson or a reference book can tell you which filter you need. Also make sure the clamps or fittings on the filter are in good shape, and replace them as needed.
Replacing the Air Filter
Air isn’t what it used to be. A car’s air filter can tell you this. Look at a used air filter and you can see a broad collection of stuff your car otherwise would have breathed. The history of air filters also illustrates the growth of pollution and a car’s need for clean air. Early cars had no air filter. Later cars had an oil-bath filter system that caught bugs and bits before they were sucked up by the carburetor. Today’s cars have large and fairly efficient filters to keep most objects out of the carburetor or fuel-injection system. Wouldn’t it be great if we all had replaceable air filters in us? Fuel-injection systems are especially sensitive to clogged air filters. Although a clogged filter won’t damage your car, it can dramatically reduce power. And a new air filter will probably cost you less than $10. Replacing your car’s air filter is one of the easier tasks you can do for your car’s health.
To replace the air filter in your car, follow these steps:
- Find the air filter. For carbureted cars, the air filter is usually located above the carburetor in a large round object euphemistically called the air cleaner. For fuelinjected cars, the filter is located somewhere between the car’s front grill and the engine.
- Remove the air filter. For carbureted cars, remove the wingnut on top of the air cleaner and lift off the top to expose the round air filter. For fuel-injected cars, remove the clips or twistnuts on the filter cover and lift the air filter from the unit, noting which way it came out so that you can put the new one back in the same way. Use an old rag to wipe out the air cleaner, discarding any waylaid bugs or other foreign objects. (I found a live salamander in one of my car’s air cleaners! Honest!)
- Replace the air filter. Place the new air filter against the old one to make sure it’s the same size. This also tells you something about the amount of contaminants your air filter stopped since it was last replaced. Install the new air filter in the same way the old one was installed. Some paper filters are wrapped with a foam blanket that initially filters bugs that have committed suicide and other large projectiles. Filters for fuel-injection systems usually go in only one way, but those for carbureted systems can go in correctly with either side up. Make sure the filter sits well and isn’t lopsided.
- Replace other parts you took off to get to the filter.
Many cars have an air cleaner that controls the source of air going through the filter and to the carburetor or injection system. It pulls warmer air from the exhaust manifold when the engine is cold and from the outside air when the engine warms up. As you work around the air cleaner, make sure the air duct from the engine sits securely in place. Visually inspect the air cleaner housing and regulator for disconnections and damage. Some older cars also have a rubber hose that feeds into the side of the air cleaner. This hose starts at a nearby tube where you pour oil for the engine crankcase, called the crankcase inlet. It recirculates fumes from the engine’s oil system through the fuel system. If your car has one of these hoses, make sure it’s snugly in place (between the crankcase inlet and the air cleaner).
Replacing Spark Plugs
Spark plugs are an important part of your car’s engine. They supply the fire that ignites the controlled explosions within each cylinder. Today’s cars are sufficiently efficient that the spark plugs need replacement only every couple of years or about 25,000 miles. Unfortunately, car manufacturers have used this fact to make spark plugs less accessible than they were on earlier engines. In fact, on some engines, it’s a chore just finding all the spark plugs, let alone trying to replace them. After you find them, you might decide to replace them yourself or to hire a dexterous mechanic for the jobTo find the spark plugs, first find the car’s distributor or ignition computer. It will have four to eight wires running from it. Follow each of these wires and you will, hopefully,find the spark plugs. Optionally, check your car’s owner’s manual or service manual for a drawing of the engine that may indicate where the spark plugs are hidden. Don’t bother cleaning and resetting the gap on used spark plugs. They’re sufficiently used up and sufficiently cheap to replace every couple of years.
To replace the spark plugs in your car, follow these steps:
- Purchase your spark plugs. Auto parts retailers can supply replacement spark plugs. However, a previous owner or mechanic might have installed spark plugs that operate at hotter or colder temperatures, so you might want to remove and check the brand and number on the plug before buying a set. Be careful of what you install because a spark plug that is too long can damage the engine’s internal parts. Your best bet is to use the spark plug recommended by the manufacturer. How many? One for each cylinder: four for a four-cylinder engine, six for a sixcylinder engine, and eight spark plugs for an eight-cylinder engine. Enough math.
- Set the gap for all the spark plugs. Spark plugs supply electrical spark to the cylinder by making it jump a small gap at the end of the plug. The gap between the center electrode and ground electrode must be exactly as recommended by the manufacturer. Use a gap gauge (a couple of dollars at the auto parts store) to set the gap between the electrodes. If the gap needs adjustment, you can carefully bend the ground or wire electrode until it is.
- Remove the old plug. First, make sure your engine hasn’t been run within an hour or more so that you don’t bum yourself on hot engine parts. After you find the spark plug, grasp the spark plug wire where it attaches to the spark plug end or terminal and carefully pull it off. Depending on how easy the spark plugs are to reach, you may need to use a spark plug wire puller (less than $10 at youknow-where). Then use an old paint brush to sweep away any dirt and debris from around the spark plugs. You don’t want that stuff falling into the cylinder hole when the spark plug is removed. Use a spark plug wrench to grasp and tum the spark plug counterclockwise to remove it. This may require some force.
- Install the new (gapped) plug. Apply some anti-seize lubricant to the threads of the plug to make removal easier the next time. If you can easily reach it by hand, place the end of the spark plug in the cylinder hole and screw it in. If you can’t quite reach it, push a 6- to 12-inch length of 3/s-inch hose on the terminal to extend your reach. Don’t force the spark plug into the hole or you will ruin the threads on the side of the plug. Tighten the spark plug into the hole using a torque wrench or a standard spark plug wrench. Overtightening can break the plug and add time and frustration to the job.
- Reinstall the spark plug wire.
- Repeat the process for the other spark plugs.
Your spark plugs may be trying to tell you something. You can learn much about the operation of your car’s engine by inspecting the old spark plugs. A service manual or an auto parts store has a chart showing what spark plugs might look like and what caused the problem: overheating, carbon, oil, poor fuel, preignition, and so on. If you don’t speak spark plug, don’t be afraid to ask a knowledgeable clerk to help you interpret what the plugs are telling you.
Replacing Spark Plug Wires
Spark plug wires used to be copper wires wrapped with a rubber insulator. Today’s wires use a carbon or silicon conductor that is more efficient, but also more sensitive to mishandling and to age. 1 know that feeling! Many car manufacturers now recommend that the spark plug wires be replaced when the spark plugs are replaced.
To replace the spark plug wires in your car, follow these steps:
- Purchase a replacement set of spark plug wires for your car as recommended by the manufacturer. A replacement set has wires cut to the correct lengths and includes contacts and boots (cowboy or hiking?) for each end. Some sets also have numbers on the wires to help you identify which cylinder they go to.
- Find the spark plug wires on your car. To do so, find the car’s distributor or ignition computer. Wires lead from it to the spark plugs. The wires may feed through one or more brackets, called looms, that isolate the wires from the maze of other wires and hoses under the hood. You might need to replace the looms, too, depending on how easy the wires are to remove from the looms. Some spark plug wire sets come with new looms or replacement bridges.
- Replace the wires, one at a time. Select one spark plug wire and trace it from the computer or distributor to the spark plug. Then select the replacement spark plug wire of the same length. Follow the instructions that came with the wire set on how to install it on your car. Some spark plug wire conductors are more sensitive to handling than others. If it feeds through a hole in a loom, you may need to remove a boot from one end to do so.
- Repeat the process for each spark plug wire until all are installed. Recheck both ends of each wire to ensure that they fit snugly.
Replacing Other Ignition Parts
Depending on what type of ignition system your car uses, other parts can need replacement. Older cars have breaker-point ignitions. Newer ones have breakerless ignitions. The newest cars have computerized ignitions. You can replace some of these parts, but you may not want to, or be able to, replace ignition parts on newer cars.
To replace other ignition parts in your car, follow these steps:
- Identify what type of ignition system your car has and what it needs. The car’s service manual tells you and also identifies the parts to be replaced. Breaker-point distributors need new contact points, a condenser, a rotor, and a cap. Breakerless ignition systems need a new rotor and cap, and sometimes one or two other components. A computerized ignition might not need anything. To find out what your car needs, identify your car to an auto parts counterperson.
- Disassemble the ignition and replace parts as described in the car’s service manual. For many cars, this means first removing the distributor cap. The distributor cap is the round plastic part that gathers the ends of all the spark plug wires. To replace the cap, first align the old and new caps side-by-side with the notch underneath both caps at the same relative position. Then remove one spark plug wire from the old cap and place it at the same position on the new cap. One-by-one, repeat this process for all spark plug wires as well as the coil wire that fits in the center of the cap.
- To replace the distributor rotor, first remove the distributor cap. Then lift the old rotor from the center of the distributor. Visually check to make sure the new rotor is the same size and shape as the old one. The hole on the underside of the new rotor has a notch that shows how it fits on the distributor shaft key. Install it by matching the notch and the key.
- To replace contact points and the condenser on a breaker-point distributor, follow the car manufacturer’s recommendations in the service manual. In most cases, the engine is rotated until the corners of the distributor shaft push the contact points open to a specific gap. Replace the old contact points with a new set and adjust the gap. Replace the condenser (this stores electricity between sparks).
- To replace parts in a breakerless distributor or a computerized ignition, follow the manufacturer’s recommendations. There are just too many variations to cover in this website.