Car Care Guide - Tips, Tricks and Answers to your most common car care questions.

Tune-Up: What Exactly Is It?

What Is a Tune-Up?

After "oil change," the phrase, "my car needs a tune-up" is the next most popular request heard in the Automotive Service and Repair Industry. When a service writer or technician asks the driver why the vehicle needs a "tune-up," the customer usually says that the vehicle is not "running right."

Maybe it's idling rough. Maybe it's hard to start. It could lack power, get poor mileage, or have many other symptoms. Many people believe that a tune-up will solve all or most of these problems, but the truth is, modern cars do not require tune-ups and poor performance almost always means the car needs a repair.

The phrase "tune-up" is from a time when automobiles were not computer controlled and an auto mechanic could actually adjust the timing, idle speed, fuel mixture, and other things in order to "tune up" the operation of the engine, similar to the way a piano tuner will tune up a piano to bring it back into proper pitch and operation by adjusting the tension on the strings, adjusting the action, and reshaping the hammers.

Maintenance: The Modern Day Tune-Up

Nowadays, the term "tune-up" actually refers to replacing and servicing the wear items in the Ignition and Fuel System. For example:

• The Air Filter and Fuel Filter will become less efficient and need replacing

• The Spark Plug electrodes will wear down and need replacing

• Because of oil vapors produced by the Positive Crankcase Ventilation (PCV) System, the Throttle Body and fuel system will need to be cleaned and/or de-carbonized

The vast majority of the time, there are no adjustments needed (or possible), because the engine computer controls all the functions of the Ignition and Fuel System. The "tune-up" is often part of a large 30,000/60,000/90,000 mile service that includes inspections, and fluid and filter changes. These services are part of the manufacturer's recommended scheduled maintenance detailed in the owner's manual.

The modern vehicle should not exhibit any performance problems by the time a "tune-up" is due. If there are any performance problems, usually a Check Engine Light will illuminate, indicating that the vehicle needs some attention because it is not running properly and is polluting the air.

Tune-Ups: Some Historical Perspective

Up until the mid 1970s, most gasoline-powered cars and light trucks had Spark Plugs, Spark Plug Wires, a single Ignition Coil, a Distributor Cap and Rotor, a set of Ignition Points, and a Condenser. A Carburetor would combine the fuel with air and then deliver this "mixture" to the cylinders. All of these components needed regular adjustments, or "tune-ups."

Compared to the vehicles of the 21st century, these technologies were very crude and required a lot of care and multiple tune-ups to properly maintain them. The Spark Timing would go out after 10,000 miles of driving because the Ignition Points would wear and become pitted or "burnt." The Spark Plugs would foul and not work properly because the Carburetor would get dirty and varnished from all of the oil vapors being recycled into the Air Cleaner from the Positive Crankcase Ventilation (PCV) System. This varnish would plug up the Air Bleeds in the Carburetor and prevent it from mixing the fuel properly with the air. The Spark Plug Wires were usually damaged from oil leaking on them from the older style cork-and-rubber Valve Cover Gaskets. It was common for a vehicle to need a "tune-up" every year, or even more often if the vehicle was driven more than 10,000 miles per year.

By the mid 1980s, most vehicles had one or two computers involved with the management of the engine operation because the Environmental Protection Agency found that when cars needed tune-ups, the amount of tail pipe emissions they were producing was increasing exponentially.

The Ignition System was the first to receive electronic and, later, computer controls. The Ignition Points and Condenser were replaced by a Transistor Controlled Ignition Module that could last the life of the vehicle. Once the Ignition Timing was set, it could stay properly adjusted for 30,000 miles or more. Valve Covers and Valve Cover Gaskets started using Air Craft Engine designs and would not leak for over 90,000 miles. This meant that the Spark Plug Wires could last upwards of 60,000 miles before they failed electrically.

By the mid 1980s, Electronic Port Fuel Injection was phasing out the Carburetor. The ratio of the Air Fuel Mixture was now computer controlled. This allowed for precise compensation to reflect the ever-changing demands put on an engine due to ever-changing driving and weather conditions. Fuel Injection is not nearly as vulnerable to the PCV oil vapors because there are individual injectors for each cylinder located away from the flow of the vapors.

By the late 1990s, most vehicles were using individual coils for each cylinder and the Spark Plugs had platinum-tipped electrodes, which eliminated Distributor Caps and Rotors and most Ignition Wires. Platinum-tipped Spark Plugs could easily go for 60,000 miles, as opposed to the usual 30,000. Some manufacturers were advertising cars that could go 100,000 miles without a "tune-up" until it was discovered that Spark Plugs rusted into the Cylinder heads. A major repair, costing hundreds if not thousands of dollars, was required to remove them. This is why 60,000 miles has proven to be a much more realistic and reliable mileage interval and why many manufacturers are switching back to this recommendation.

Brake System Maintenance

Most of us don't think about our car's brakes until we need them for a panic stop, hear a screeching or grinding noise, or when a warning light comes on. But brakes are worn down every time you drive your car. It's important to keep them maintained and serviced—before you hear that screeching. The sooner the better... and cheaper.

All cars incorporate some type of brake warning system to inform the driver of a problem. A warning light is the most common. It typically alerts a driver to:

• Low brake fluid

• Brake system hydraulic pressure failure

• An applied parking brake

• An ABS malfunction

• Brake pads need replacement

• An inoperative brake light bulb

Some systems have metal clips that rub on the rotors when pads are worn out. This causes a high-pitched, fingernails-on-a-chalkboard screech when the brake pedal is pressed. Some newer vehicles alert the driver in a more civilized and agreeable manner with warning lights or computerized messages. No matter which your vehicle has, it's critical to address the issue promptly.

Belts and Hoses

How often should belts and hoses be replaced?

The typical lifespan of a hose is roughly 6 years or 60,000 miles.
However, the best way to know if a hose is due for replacement is to inspect the condition of the hose. The simplest way to check the condition of a hose is to squeeze the hose. If a cracking sound is felt or heard, then the webbing in the hose has deteriorated and is due to be replaced before it bulges and bursts while driving down the road. Another way to check a hose is to feel for any “soft” spots on the hose where certain areas like on the outside corners are softer than the rest. In this case, the hose should be replaced.

The typical lifespan of a belt is rougly 5 years or 50,000 miles depending on the style of the belt. The V-belt style has shorter lifespan than the Serpentine belt style. Serpentine belts are thinner and more flexible than V-belts. They run cooler and last longer, but they cost about twice as much to replace. The best way to know if a belt should be repllaced is to look for cracks around the belt, They will usually be in the inner part of the belt. If cracks are seen, the belt is due for replacement.

Scheduled Maintenance

Scheduled Maintenance, or preventative maintenance, is the regular schedule of services that vehicles manufacturers prescribe to keep a car running well and safely. Maintenance schedules vary by vehicle, driving style, and driving conditions.

Are You a "Normal" or "Severe" Driver?

When it comes to maintenance advice, consumers are confronted with numerous recommendations and opinions. When the owners manual recommends one type of service, a quick lube franchise recommends a second, and the dealership advises a third, it’s no wonder consumers are afraid they’ll be ripped off by paying for service they don’t really need. Sometimes it’s impossible to know who’s telling the truth and who isn’t.

The truth is in the owners manual. Manufacturers define maintenance schedules for your car, not dealerships—and certainly not quick lube franchises. Most manufacturers divide maintenance schedules into "normal" and "severe" driving conditions.

You might think the conditions you put your car under aren’t considered severe, but if you frequently do any of the following, then your car maintenance should indeed follow the "severe" driving conditions schedule:

• Take short trips of less than 10 miles.

• Drive in heavy traffic with many stops and starts.

• Drive at high rates of speed.

• Tow heavy loads or drive off-road.

• Drive in dusty conditions.

• Drive in extremely cold or extremely hot climates.

Surprised? Many consumers are.

If the above conditions are severe, then what’s normal?

• Trips of 10 miles or more.

• Sustained speeds of 50 to 75 miles an hour.

• Driving in low-traffic situations with few stops and starts.

• Ambient temperatures above freezing and below 95 degrees Fahrenheit.

Determine what your expectations and priorities are to make the most informed decisions about your car’s maintenance schedule. A mother of small children may make decisions based on safety. A person commuting to work may be concerned about fuel economy. A student might make maintenance decisions based on cash flow—or lack thereof. Each of us has different priorities and circumstances.

As sensible car owners, we all must assume responsibility for doing the basics. Periodically checking tire pressure, engine oil, and coolant levels can dramatically increase the life of your car and potentially save you thousands of dollars in repairs down the road. And not only does a well-maintained car last longer and save money in the long run, but it’s also much safer for both you and your passengers.

Check Engine Light: What It Means and What to Do

The Check Engine Light (CEL) is a warning indicator—it means your vehicle's computer has determined that a component or system in your emission control system is not working properly. When the light comes on, one or more diagnostic trouble codes (DTC) are stored in the Engine Control Module. These DTCs remain even if the light goes out. To address a Check Engine Light problem, the DTCs are retrieved and the appropriate troubleshooting information is followed in order to determine the problem.

Every vehicle manufactured in the U.S. has to first pass an Environmental Protection Agency (EPA) test called the Federal Test Procedure. This sets the acceptable limits of wear and/or failure for the emission control system—i.e., what conditions will ultimately cause a Check Engine Light to illuminate. These standards are closely regulated.If the emission control system is faulty and the vehicle is polluting the air, the Check Engine Light illuminates to alert the driver of this condition. (Note: A vehicle in this condition would fail an emissions inspection or smog check.)

Don't confuse the Check Engine Light with the maintenance or service light. These lights illuminate when a routine service is due. They are usually triggered by mileage, gallons of gasoline consumed, or some other type of vehicle-use measurement.

The Four Most Common Check Engine Light Scenarios and What to Do

The Check Engine Light turns on and off or flickers.
If the Check Engine Light comes on in the city but goes off on the freeway, then the fault is present during city driving conditions. Pay attention to whether or not the vehicle runs or drives any differently when the Check Engine Light illuminates. If vehicle performance does change, drive the car as little as possible and take it to be checked by a service professional as soon as possible. If there is no change in vehicle performance, you can drive home, but have it inspected as soon as possible. In this condition, you run a risk of the vehicle dying or not starting.

The Check Engine Light comes on and stays on.
If the Check Engine Light illuminates constantly during driving with no noticeable driving or performance problems, there is a permanent fault in the emission control system. When this happens, the computer that controls the emission system usually has a backup program that runs while the fault is present. (These backup programs are often referred to as "limp home" mode programs.) You should get the vehicle serviced as soon as possible, but in most cases, the vehicle will continue to operate, though you run a risk of it dying or not starting.

The Check Engine Light illuminates, stays on, and there are performance problems.
This means that a vital component of your emission control and engine management system has a serious problem. It usually involves a component or system needed for the vehicle to run at all. In most cases, drive the vehicle as little as possible. In many cases, the vehicle is not safe to drive at all—it could stop or stall out at any moment. It is best to pull over to a safe place and have the vehicle towed to an automotive diagnostician for a thorough inspection and repair.

The Check Engine Light comes on and blinks in a steady pattern while driving.
Don't confuse this steady pulsing of the Check Engine Light (usually one or more flashes per second) with a flicker (see above). The Check Engine Light may stay on steadily or it may flash when the vehicle is accelerated. This is very serious. There is a severe failure of the emission control system that is causing the engine to misfire to the point that the catalytic converter is damaged each time the Check Engine Light flashes. It may mean that the catalytic converter is overheating to the point that it will glow red or, in extreme cases, start a fire on the underside of the vehicle. Immediately pull over to a safe place and have your vehicle towed to an automotive diagnostician for repair. Vehicles can be severely damaged and even destroyed by fire if this condition is ignored for too long.

Emissions

Emission control systems reduce the amount of harmful gases and particles released by vehicle operation. These systems have evolved into complex computer-controlled systems that balance ever-tightening vehicle pollution control regulation by the U.S. government with the constant demand for more power and economy from vehicle owners.

When an engine operates, it burns fuel. Because no engine can burn 100 percent of the fuel, harmful gas and particulate byproducts (emissions) are released.

The Clean Air Act Extension in 1970 mandated that the Environmental Protection Agency (EPA) "develop and enforce regulations to protect the public against airborne contaminants that are known to be hazardous to human health." The EPA found that motor vehicles produced three main types of harmful gases and particulates:

Hydrocarbons (HCs)
Raw, unburnt fuel particles from the combustion process that are suspended in the exhaust gases or released in a raw state from the fuel storage and crankcase systems.

Carbon monoxide (CO)
A fuel and oxygen gas formed from incomplete combustion.

Nitrogen oxide (NOx)
A nitrogen and oxygen gas compound that is formed when combustion temperatures go above 2500° F.

In conjunction with the EPA, vehicle manufacturers from around the world developed vehicle emission control systems and devices to control (and in some cases eliminate) the production of these harmful emissions. Vehicle emission control systems use a two-tiered approach in the management of these harmful substances.

Upstream Emissions Control
Manages the pre-combustion and combustion process and recycles leaked fuel storage vapors and crankcase vapors into the combustion flow.

Downstream Emissions Control
Monitors the results of the combustion process by constantly testing the oxygen content in the exhaust system before and after the catalytic converter. This information is fed to the engine management computer, which adjusts the combustion process, thereby completing a "closed loop."

The catalytic converter provides a means to "after burn" the three remaining harmful substances (HCs, CO, NOx) and converts them back into the non-poisonous substances of carbon dioxide (CO2), oxygen (02), and water (H20). Some vehicles deploy the use of a secondary air injection system to provide the extra oxygen needed at critical times to complete the combustion process. This secondary air is injected into the exhaust manifold(s) and/or catalytic converter(s) by a computer-controlled electric pump or pulse valve(s) and is distributed by specialized plumbing and check valves.

Common Upstream Emission Control Systems

• Positive Crankcase Ventilation (PCV) System

• Evaporative (EVAP) System

• Exhaust Gas Recirculation (EGR) System

• Fuel Management System

• Spark Control System

• Variable Valve Timing System

The cooling system and thermostat have recently been included in the upstream emission controls. The cooling system provides accelerated engine warmup by restricting the amount of coolant flow. The cooling system also provides an ever-narrowing window of allowable operating temperature by utilizing more advanced thermostat design and computer-controlled, speed-varied cooling fan(s) operation. This allows the engine to reach and maintain optimal air-to-fuel burning temperature as quickly as possible, thereby minimizing the "dirty" warmup emissions output and maximizing overall fuel economy. A cold (or cool) engine needs a wasteful "rich" air-to-fuel mixture in order to operate and compared to a properly warmed-up engine, its combustion only burns a fraction of this "rich" mixture. An engine that runs too hot will produce nitrogen oxide (NOx) and will misfire, which produces hydrocarbons (HCs) and NOx. The cooling system controls maintain the ideal engine temperature range of 195 to 205° F.

The comprehensive component monitor is a software program inside the engine management computer that continually monitors the performance of the upstream emission control sensors and actuators. It constantly compares the sensor readings to each other in order to verify that the readings are within "rational" tolerances (e.g. is the intake air temperature sensor within a "rational" range of the engine coolant temperature sensor?). If it is not, then an emissions code will be set and the Check Engine Light will illuminate. The comprehensive component monitor also allows for adaption of the range (within preset limits) of the sensor readings to account for engine and component wear. This adaption is then shared with the other upstream emission systems, which modify their operating parameters to account for engine and component wear.

Downstream Emissions Control Systems

• The exhaust manifold is the first downstream emission control device

• The catalytic converter is a sophisticated after-burning device designed to complete the combustion of the exhaust gases that pass through it

• The secondary air system adds oxygen to the exhaust gases under specific operating conditions to aid in the final "burn off" of the emissions

• The oxygen sensor is a device that constantly monitors the oxygen content in the exhaust gases and sends this information back to the engine management computer (ten or more times per second)

Emissions systems also gave birth to fuel injection, which is now found on virtually every modern vehicle. It increases engine efficiency by injecting precise amounts of fuel in a fine mist spray for optimal combustion. This greatly reduces unburnt fuel (hydrocarbons) emissions and reduces the amount of fuel required.

Heating and Air Conditioning

Your car's heating and air conditioning systems control the temperature of the vehicle's cabin. So whether it’s Fourth of July in Death Valley or Christmas in Green Bay, at least you’ll be comfortable in your car—provided these systems are working properly.

The AC system operates by compressing and expanding refrigerant to transition it between liquid and gaseous forms. Liquid absorbs heat when it becomes a gas; gas gives off heat when it becomes a liquid. Using these thermodynamic properties, heat is removed from the passenger compartment and released to the outside air while cool air enters the passenger compartment.

Cars use two different types of refrigerant.

• R12 (Freon) was invented in 1928 and discontinued in the early 1990s after being found to have significant ozone layer–depletion properties.

• R134a is a more environmentally friendly option to R12 used in modern cars and to recharge AC systems in older cars.

The AC system consists of 5 components.

• The compressor is the heart of the system. The compressor is a belt-driven pump fastened to the engine. Refrigerant is compressed and then turned into a hot gas before traveling to the condenser.

• The condenser is where heat dissipation occurs. It uses the air passing through to absorb heat, so the refrigerant can cool and become a liquid.

• The dryer functions as a refrigerant filter, removing moisture and contaminants.

• The orifice tube/expansion valve is a filter that regulates how much refrigerant is released into the evaporator. In older cars, the refrigerant flow is measured and regulated by an expansion valve. As the refrigerant passes through either device, it expands and becomes partly vaporized, rapidly cooling it off.

• The evaporator removes heat from inside the car. Refrigerant enters the bottom of the evaporator as a liquid. The warm air passing through the evaporator fins causes the refrigerant to boil. As it boils, it absorbs large amounts of heat. This heat is carried off with the refrigerant to the outside of the vehicle, leaving cooled air. Fans blow the cooled air into the passenger compartment.

If your car is overheating, turn off the AC, open all the windows, and blast the heater. This is because your car's heating system is a smaller version of the engine’s cooling system. Hot engine coolant circulates through the heater core, which is basically a mini radiator. A fan (blower motor) that sits in front of the heater core moves the air past it. As this air passes over the core, it heats up and passes through the heater vents into the passenger compartment. Although dissipating this hot air might not keep you cool and comfortable on a hot day, it will help prevent your car from overheating, so you can visit your mechanic before serious engine damage occurs.