Tune-Up: What Exactly Is It?
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.
Nowadays, the term "tune-up" actually refers to replacing and servicing the wear items in the Ignition and Fuel System. For example:
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.
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.
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:
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.
How often should belts and hoses be replaced?
The typical lifespan of a hose is roughly 6 years or 60,000 miles.
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, 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.
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:
Surprised? Many consumers are.
If the above conditions are severe, then what’s normal?
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 Check Engine Light comes on and stays on.
The Check Engine Light illuminates, stays on, and there are performance problems.
The Check Engine Light comes on and blinks in a steady pattern while driving.
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.
Nitrogen oxide (NOx)
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
Downstream Emissions Control
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
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
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.
The AC system consists of 5 components.
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.
Brake Fluid Maintenance
Brake fluid is one of the most neglected fluids in vehicles today, yet is vitally important for safe driving. Consequently, professional technicians should be checking the fluid and recommending that the brake fluid be changed if it is contaminated. The issue is old brake fluid may not be safe if moisture contamination is above a certain level.
Many experts have long recommended changing the brake fluid every year or two for preventative maintenance. Their rationale is based on the fact that glycol-based brake fluid starts to absorb moisture from the moment it is put in the system. The fluid attracts moisture through microscopic pores in rubber hoses, past seals and exposure to the air. The problem is obviously worse in wet climates where humidity is high.
After only a year of service, the brake fluid in the average vehicle may contain as much as two percent water. After 18 months, the level of contamination can be as high as three percent. And after several years of service, it is not unusual to find brake fluid that contains as much as seven to eight percent water.
An NHTSA survey found that the brake fluid in 20% of 1,720 vehicles sampled contained 5% or more water!
As the concentration of moisture increases, it causes a sharp drop in the fluid's boiling temperature. Brand new DOT 3 brake fluid must have a dry (no moisture) boiling point of at least 401 degrees F, and a wet (moisture-saturated) boiling point of no less than 284 degrees. Most new DOT 3 fluids exceed these requirements and have a dry boiling point that ranges from 460 degrees up to over 500 degrees.
Only one percent water in the fluid can lower the boiling point of a typical DOT 3 fluid to 369 degrees. Two percent water can push the boiling point down to around 320 degrees, and three percent will take it all the way down to 293 degrees, which is getting dangerously close to the minimum DOT and OEM requirements.
DOT 4 fluid, which has a higher minimum boiling temperature requirement (446 degrees F dry and 311 degrees wet) soaks up moisture at a slower rate but suffers an even sharper drop in boiling temperature as moisture accumulates. Three percent water will lower the boiling point as much as 50%!
Considering the fact that today's front-wheel drive brake systems with semi-metallic linings run significantly hotter than their rear-wheel drive counterparts, high brake temperatures require fluid that can take the heat. But as we said earlier, the brake fluid in many of today's vehicles cannot because it is old and full of moisture.
Water contamination increases the danger of brake failure because vapor pockets can form if the fluid gets too hot. Vapor displaces fluid and is compressible, so when the brakes are applied the pedal may go all the way to the floor without applying the brakes!
In addition to the safety issue, water-laden brake fluid promotes corrosion and pitting in caliper pistons and bores, wheel cylinders, master cylinder, steel brake lines and ABS modulators.
FLUID RELATED BRAKE FAILURES
From time to time we hear about reports of "unexplained" brake failures that caused accidents. When the vehicle’s brakes are inspected, no apparent mechanical fault can be found. The fluid level is normal, the linings are within specifications, the hydraulics appear to be working normally and the pedal feels firm. Yet the brakes failed. Why? Because something made the brakes hot, which in turn overheated the fluid causing it to boil. The underlying cause often turns out to be a dragging rear parking brake that does not release. But that's another story.
The same kind of sudden brake failure due to fluid boil may occur in any driving situation that puts undue stress on the brakes: a sudden panic stop followed by another, mountain driving, towing a trailer, hard driving, etc.
A case in point: A child was killed in an accident when the five-year old minivan with 79,000 miles on it his parents were driving suffered loss of pedal and crashed while the family was driving in the mountains of
OEM BRAKE FLUID RECOMMENDATIONS
What do the auto makers say about fluid changes? General Motors and Chrysler do not mention brake fluid in their scheduled maintenance recommendations. A General Motors spokesman said Delco Supreme 11 DOT 3 brake fluid contains additives than many other brake fluids do not, so it is essentially a lifetime fluid. Starting in 1993, GM began using a new type of rubber brake hose with an EPM lining and outer jacketing that reduces moisture penetration by 50%. So GM does not consider fluid contamination to be a significant problem.
Ford, for a time, recommended fresh fluid every 36,000 miles or three years, and to replace the fluid each time the brake pads are changed. Currently, however, Ford specifies no specific time or mileage recommendation for changing the brake fluid.
As for Chrysler, the only recommendation they publish is to change the fluid every 24 months on their Sprinter van.
A number of import car makers do recommend brake fluid changes for preventive maintenance at specific time/mileage intervals:
If motorists would only follow this simple advice to change their brake fluid periodically, they could greatly reduce the risks associated with moisture-contaminated brake fluid. You can extend the life of your brake system and likely save yourself a lot of money in the long run on brake repairs, especially if your vehicle is equipped with ABS (because ABS modulators are very expensive to replace!).
Power Steering Fluid Maintenance
Pint-for-pint, the three or four quarts of power steering fluid required by your vehicle are probably some of the least appreciated fluids under the hood. Considering what it does, and how much a motorist depends on it, we're talking about the lifeblood of your steering system. Yet keeping it clean and doing its job doesn't require all that much effort.
The function of this fluid is basic: transmitting hydraulic pressure to make steering easy—but achieving a seamless system operation over a wide variety of conditions is not. The fluid must perform consistently in any situation, from sub-zero to triple-digit temperatures, and both ambient and under-hood temperatures. It also must function when the engine is at idle or full-throttle, and under high pressure, all the while providing adequate lubrication to pump and control valve assemblies, maintaining integrity of rubber components in the system, and promoting noise-free system operation. And your fluid has to do all of these things over an extensive period of time!
Of course, these demands take their toll on the fluid and break it down, which can lead to inconsistent performance and expensive component failure. Although vehicle manufacturers haven't generally specified in the past when to actually change the fluid, some are doing this now, or they have designed a fluid that they feel will last "the life of the vehicle." Of course, your opinion on a vehicle's lifespan may differ from that of the manufacturer. That said, we'll share a couple of relatively simple and mess-free methods for maintaining the fluid for a much longer period.
If your vehicle's manufacturer recommends a fluid change interval, definitely follow that. Do-it-yourselfers will need to consult a service manual for the procedure on their particular vehicle. If there is no recommended change interval, however, here's a good rule of thumb to follow: Change it as often as you would your engine coolant. Power steering fluid of the "long-life" variety should be changed every five years or 100,000 miles. For conventional fluid, the interval is every three years or 50,000 miles. Most likely, the fluid will appear normal at this point—either amber (on most vehicles) or pink/red in color. This is good, as no serious problems are indicated.
As with other vehicle fluids, changing before visible deterioration occurs is ideal. The fluid should be checked at every routine service interval, but if at any time before the interval recommended here, it appears significantly darker than new fluid, it should be changed at that time. Use the following easy procedure for evacuation and filling.