It should be obvious that the internal combustion engine and the starting, charging and ignition parts that make it go will be around for a long time to come. Your grandchildren may be zipping around in high-tech vehicles propelled by electric motors, fuel cells and hydrogen gas, but for the next 20 years or so, it will still take a starter to crank the engine, an alternator to keep the battery charged and spark plugs to ignite the fuel. These parts are not going to disappear off jobber shelves any time soon - if ever.
The replacement rate for starters has declined steadily since the late 1980s when electronic fuel injection replaced carburetors. The reason: EFI motors start easier. Consequently, the starter doesn't have to crank as long and lasts longer.
Even so, starter problems can be caused by worn brushes, by shorts or opens in the armature or field coils, or by worn bushings that increase drag inside the starter. Continuous prolonged cranking is very hard on all starter motors because it can make the motor overheat. And once the starter dies, the motorist isn't going anywhere because the engine can't be started (unless it's stick, and you can roll it down a hill and pop the clutch).
When a starter may have failed, it should be bench tested to confirm the diagnosis before it's replaced. Misdiagnosed starter problems are a common cause of warranty returns. Many problems can prevent an engine from cranking or starting: a bad battery, loose or corroded battery cables, a bad starter relay or solenoid.
The only accurate way to test a starter is with a test stand that can measure the amp load, voltage and rpm. A good starter will normally draw 60 to 150 amps with no load on it, and it will draw up to 250 amps under load (while cranking). The no-load amp draw, when it spins, will vary depending on the type of starter. If the amp draw is out of specifications (too high), your customer needs a new starter. The same is true if the starter doesn't achieve the specified rpm.
In the future, we may see some starters disappear. Auto makers say 42-volt electrical systems are coming because more voltage is needed to handle new onboard electronics, exotic stuff like all-electronic steering and braking and electrically-driven A/C compressors. They'd also like to combine the starter and alternator into one unit, and possibly incorporate both into the flywheel as part of a stop-start fuel-saving system or a hybrid-electric powertrain. The Toyota Prius hybrid electric uses such a setup now.
Charging is a full-time job any time the engine is running. As soon as the engine starts, the charging system kicks in and begins to replace the amps used to crank the engine. It also provides additional juice to power the ignition system, computer, fuel injectors, fuel pump, HVAC system, lights, radio and everything else that demands amps. It's quite a load - one that can fry an alternator when loads are too high for too long.
Every replacement alternator should have the same or higher amp capacity as the original. Undersized alternators don't last long. Also, make sure the pulleys are the same and the fans turn in the same direction (some units that look alike may turn clockwise or counterclockwise).
Like starters, many alternators are replaced unnecessarily or are returned because of misdiagnosed problems. If possible, bench test the customer's old alternator. If it can't output the required voltage and current at the specified rpm, it needs to be replaced.
The battery should also be tested - and fully recharged - before the replacement alternator is installed. This step alone can probably eliminate half of all warranty returns.
Neither the starter nor the alternator will function properly if the battery is low or worn out. A low battery can upset the normal operation of the engine computer and other onboard electronics. Average battery life under the best circumstances is only four to five years, and as low as three years in really hot climates.
If the charging system is functioning normally, but the battery fails to hold a charge, the battery may have reached the end of its service life. Load testing the battery or using an electronic tester to check battery amp capacity should reveal the health of the battery. If your customer needs a new battery, the replacement must have an amp capacity that equals or exceeds the OEM cold-cranking amp (CCA) requirements. The group size (height, width and length) must also fit the battery tray in the vehicle, and the posts must have the same configuration. New battery cables may also be needed if the old ones are badly corroded or don't fit the batter posts tightly.
IGNITION: PLUGS OR NO PLUGS?
Europeans have had a long-standing love affair with diesel engines because of the high fuel economy diesels deliver, which makes filling up at $4 to $5 a gallon a little less painful. With electronic direct injection, most of the clatter and smoke is gone. Add a turbocharger, and you can squeeze some serious performance out of a pint-sized diesel engine. That's why nearly half of the vehicles in Europe today don't have spark plugs. They're diesel-powered.
It's a different story here. Gas is still cheap, even at $1.50 to $1.75 per gallon. Except for the big, turbo-diesel sixes and eights that have been a popular option in full-size pickup trucks and big trucks, diesel power plants are virtually nonexistent in domestic passenger cars.
Car makers here don't offer diesel options because there's too much uncertainty over future emission rules. They don't want to invest millions in tooling to build diesel engines for cars if nobody will buy, and especially if they're legislated out of existence by new emission regulations. This is good news for spark plug manufacturers, which have already seen a big decline in replacement spark plug sales because of 100,000 replacement intervals.
Long-life, platinum-tipped spark plugs are used in most new vehicles because they provide significant benefits to the vehicle manufacturers and vehicle owners. Long-life plugs allow vehicles to meet emissions for up to 100,000 miles and reduce the need for maintenance. But the trade off is fewer replacement sales and less ignition-related service and repairs. Fortunately, long-life spark plugs have also created a tremendous sales opportunity for the aftermarket by providing a "premium" (and more profitable) product you can sell to your customers.
One spark plug manufacturer said the sales of their premium platinum spark plugs continues to gain market share and outpace all of their own projections. Why? Because many people see the advantages of installing premium spark plugs (longer life, fewer misfires, better performance, fuel economy and emissions) and will spend a few extra bucks over the price of a standard spark plug to upgrade the ignition system when the plugs are replaced.
Platinum has become the buzzword for ignition durability. Platinum is a good conductor of heat and electricity, and it resists chemical corrosion and electrical erosion. That's why platinum is used on the electrodes of many spark plugs today. Some have a solid platinum center electrode, while others have a small button of platinum welded onto the tip of the center electrode or both electrodes (single platinum vs. double platinum).
Platinum minimizes electrode wear. Every time a plug fires, a tiny amount of metal is vaporized and erodes from the surface of both electrodes. The center electrode typically suffers the most wear because it runs hotter than the side electrode. As the electrodes wear, the air gap across which the spark must jump becomes wider and wider. The gap on a standard spark plug grows about 0.00063 to 0.000126 inch for every 1,000 miles of driving. And the wider the gap, the greater the voltage needed to jump the gap.
On standard plugs with conventional electrodes, the firing voltage requirements typically creep up about 500 volts for every 10,000 to 15,000 miles of driving. Eventually the plugs may need more volts to fire than the coil(s) can produce, resulting in ignition misfire, which can cause the Check Engine light to come on.
Using platinum almost eliminates electrode wear. Platinum is expensive, but it can double or triple a spark plug's normal service life - from 30,000 to 45,000 miles for a standard plug and up to 80,000 to 100,000 miles or more with platinum. Most aftermarket plug suppliers don't make specific mileage claims for their platinum plugs, but say to follow the OEM replacement intervals - which in most cases is 100,000 miles for OEM platinum plugs.
Plug manufacturers are also using other exotic materials in spark plug electrodes to extend plug life. Some of today's platinum plugs have side electrodes made of nickel-yttrium, chromium-nickel or silver-nickel alloys. In Europe, there are plugs that use yttrium for both the center and ground electrodes. The "newest" electrode material, though, is iridium, which is said to have even better corrosion and wear resistance.
Regardless of what types of metals or electrodes are used in a spark plug, no plug will magically transform a Kia into a Corvette. But premium plugs will provide the best possible ignition performance and continue to do so for a longer period of time than standard spark plugs.