The Tune-Up -- Shattering the Myth

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Shams + Scams | Glossary

The auto repair customer is often shammed during a basic and/or major tune-up. Actually, a tune-up is not a repair so much as it's a preventive maintenance—a service which restores a vehicle to a state of maximum efficiency for the purpose of maintaining good performance and fuel economy. The term “tune-up” has become synonymous with duty, as though it were a true test of the vehicle owner’s dedication and responsibility. To many, it's something that must be done on a strict and regular basis, and it's perceived to be a cure-all for whatever ails your car. It is a catch phrase that promises everything will be just fine after it's performed. Many of you purchase a tune-up without really knowing what it entails or what it's supposed to include and deliver in standard practice. The tune-up is the scapegoat of the engine: far too many ills are diagnosed as tune-up problems, and far too many customers sign the work orders prescribing the service.

I’ve heard of customers who insisted on tune-ups only to find out later that it was another area of their engine that needed repair, and they okayed the additional work with the shrug of a shoulder. Their comments were always the same, “Well, it was about due for a tune-up anyway.”

Do the managers or mechanics argue with this reasoning? Of course not, because they have known all along that the average automobile owner believes that any tune-up is a good tune-up; tune-ups are fault less, blameless, they are a recognized, mandatory service. Once that impressive oscilloscope is rolled out onto the tarmac, customers think that this mysterious machine will somehow make everything all right. Therefore, customers often oversell themselves a tune-up. The mechanics just agree, perform the work, find the real problem and collect more money.

In this section we will venture into the mysterious realm of the tune-up and discover just what it's , why it's needed and how often it should be performed.


The two most important reasons for a tune-up are to maintain fuel economy and engine performance. Certainly, the more efficiently an engine performs, the less fuel it will need. Reliability is also enhanced.

Like moths to flames, customers flock to the outlet that's running that advertised coupon special, and sign up for the work believing that they just received a whopping discount. What they fail to consider is that their vehicle might have just had a tune-up some six months or 6,000 miles back. This kind of tune-up would be even premature for a car equipped with standard ignition (the older breaker points and condenser system). If they had an HEI (high energy ignition) system, and tuned up after just 6,000 miles since the last one, the decision could conceivably be 25,000 miles, or two years premature! Can a car equipped with modern electronic ignition go 20,000 miles before a tune-up is needed? You bet it can! Although the average is somewhat lower, the point is that vehicle owners who have been accustomed to tuning their vehicles much more frequently with older ignition systems still believe that this is the correct schedule to adhere to when their vehicles are equipped with present day electronic ignition.

Bad Gas—Have you ever pulled out of a gas station with a full tank of gas and discovered that your car is running rough? Don’t rush down the street for a tune-up—it just might be some bad gas. Bad, or contaminated gasoline is the probable result of water that has seeped into the underground holding tanks. When that water gets into your fuel tank, your engine will run rough until it evaporates or is used. There are special fuel additives you can buy to remedy this problem.


What are the plus sides to overly frequent tune-ups? Your engine will run efficiently and smoothly with more reliability. You might save money in the long run because you’ll keep the fuel economy up. A major spark plug manufacturer did a survey of over 6,000 cars nationwide. They found that a tune-up, on cars that needed one, increased fuel economy by over 11%. Replacing worn spark plugs alone accounted for a 3% increase. The same test revealed that eight out of every ten vehicles will have some maintenance deficiency that will directly affect fuel economy, emissions or performance. The best guideline is your owner’s manual. It is best to follow the recommended intervals for tune-ups suggested by the manufacturer.


Most facilities only include a certain number of parts in a tune-up package, such as plugs, condenser, points, timing and carb adjustment. Anything else that falls outside this area, such as a bad plug wire or vacuum hose, will be charged at premium prices. Tune-ups from dealerships are naturally going to cost more. This is because they are providing the service with the replacement of original factory parts which cost more, along with a higher labor charge. When confronted with an advertised special tune-up package for one price, be certain that you get a complete list of what’s included. Don’t authorize any other parts or repairs.


Standard ignition refers to the older type ignition system used on older model cars. The parts involved in a tune-up on these cars consist of breaker points, condenser, spark plugs, rotor and sometimes the distributor cap.

On standard ignitions, the replacement of these parts and a carburetor and timing adjustment, would be considered a minor or standard tune-up. It is the minor tune-up that's most frequently performed nowadays. On standard ignition-type cars, this service would ordinarily be performed about every 8,000 to 12,000 miles, perhaps 15,000 miles if the driving conditions are moderate.

Electronic ignitions, on the other hand, are much more sophisticated and require a different type of tune-up. Electronic ignitions are almost standard on all cars built within the last decade or so. We’ll discuss both types of ignitions, and the procedures involved in tune-ups for both.


Every shop has its definition of what constitutes a major tune-up, and you’d be well advised to call around to make sure you find one that offers the most service for the best price. I will list the chores and parts normally associated with maximum service. That would include:

points (if so equipped), distributor cap, rotor, condenser, replacement of all spark plug wires, PCV valve (if so equipped), PCV filter (if so equipped), complete carburetor and timing adjustment, air cleaner element, valve adjustment (if equipped with solid lifters), fuel filter (carburetor and inline) and any emission control adjustment.

Sometimes a lube, oil and filter are included in a major tune-up price—again, that depends on the facility.

The following is a brief description of the major tune-up elements, their function and some common problems that occur with them.


Actually, the spark plug does not produce a spark but provides a gap across which the current can jump or arc. The gap is the distance between the two electrodes—one in the center and one curving over the top of it. This hot spark ignites the air/fuel mixture inside the engine (in an area called the combustion chamber) and this explosion is what produces the power to make your car move. The plug must fire (ignite) thousands of times per minute. If it doesn’t, then you have what is known as a miss.

Wear—Spark plugs wear in the area directly between the gap, making the gap wider. Then the spark has further to jump, and its response gets sluggish. This is why a high speed miss in the engine is sometimes more noticeable than at idle or low speed.

Heat Range—Spark plugs have a heat range, which is the ability of the plug to dissipate heat. The further the plug extends into the engine head (the longer the insulator), the hotter the plug will operate; the shorter the insulator the cooler it will function. A cooler plug will quickly accumulate deposits of oil and carbon since it's not hot enough to burn them off. This results in plug fouling and a direct result is sporadic or complete misfiring. On the other hand, a plug that has too high a heat range will burn away the electrode contacts quickly, and sometimes cause pinging or knocking which is formally known as detonation. This can lead to serious engine failure.

Generally, if most of your driving is long distance, at high speed, a cooler range plug is preferred while if most of your driving is stop and go in city traffic, a hotter range is desired. Most new cars with original equipment plugs are of a medium heat range capability, affording a compromise between the two extremes. What most people don't realize is that they can actively choose which heat range best suits their driving conditions. The heat range marking can be found written on the spark plug body. Generally, higher numbers indicate higher heat ranges; lower numbers, lower ranges. There are spark plug charts available that indicate these heat range sizes.

Inspection—It is a relatively simple matter to check the condition of your spark plugs by removing them one at a time and inspecting them for wear and discoloration. If that turns you off, at least you should be familiar with the visual signs so you won’t be misled when the mechanic shows you “fouled plugs.” You can also get an idea of the condition of your internal engine parts.

Normal plugs have a specified gap measured in thousandths of an inch. This increment can be found by sliding a gap or feeler gauge of the same size as the gap specified by your car’s manufacturer, in between the electrodes. A snug fit of the gauge (according to specifications) is desirable. The adjustment can be made to narrow the gap by bending the tang of the upper electrode down toward the center electrode, or bending it up to increase the gap.

The visual appearance of the plug is just as important as the gap. The end electrodes on a plug, in a normal condition, will appear a tannish or gray color with perhaps a little electrode wear. It might show signs of slight crust or brownish deposits but this can be considered normal. Assuming that the vehicle is running normally, the coloration is right and the gap is sufficiently set, a plug like this would be considered in good shape and firing properly.

The effects of extremely high temperatures or incorrect heat range can be seen on a plug as a white or blistered insulator. This can also show up as excessive or premature wear on the insulator due to heat. It can be the result of improperly set ignition timing, a low cooling system, a lean carburetor condition or a leaking intake manifold (which allows too much air into the fuel mixture).

If all the other systems are in proper working order, and the plugs still exhibit an overheated or blistered condition, then it would be wise to exchange the plugs with a set a heat range colder.

If the firing end of the plug is covered with a wet and oily coating, it usually indicates oil deposits. More than ever, oil-fouled plugs are found in engines that have a high amount of wear or a mechanical malfunction.

Oil that has reached the plug has done so by passing the piston rings, valve guides, or possibly a blown head gasket. Remember that when any car has oil-fouled plugs it means that a certain amount of oil is passing through the exhaust (being burned by combustion) and if that's the case, you’ll often see blue smoke puffing out the rear of the car.

The installation of a hotter range plug can sometimes remedy the fouling problem; only this method is temporary until the defective parts are replaced (the rings, valve guides, etc.)

Carbon-fouled plugs are identified by the presence of dry, soft, black, sooty deposits on the electrodes. Carbon-fouled plugs are typical in cars subject to continuous stop-and-go city driving. Assuming that the plug heat range is correct, carbon-fouling can be caused by a rich fuel mixture (carburetor or fuel injector malfunction), sticking choke, abnormal fuel pump pressure, clogged air cleaner, retarded ignition timing, or overall low cylinder compression. If one or two plugs are badly carbon-fouled, check the condition of the respective plug wires for cracks and bare wire. (A noticeable engine miss can carbon-foul the defective plug). Also look for cracks in the distributor cap between the towers of the affected cylinders i.e., plug number one, two, three, etc.

Carbon-fouled plugs can be easily cleaned and re-gapped; there is no need to replace them unless the electrodes are obviously worn.

Detonation (pinging) is usually characterized by a broken plug insulator (the ceramic material surrounding the center electrode). Detonation can also be the result of over-advanced ignition timing, inferior gasoline (low octane), a lean air/fuel mixture (carburetion or fuel injection malfunction), engine lugging (very slow driving), or a non standard application of engine components that boost the compression ratio causing chamber deposits.

Sometimes the excessive use of gasoline additives can cause ash or lead deposits on the spark plugs. It can be seen as light brown or white colored deposits crusted on the side or center electrodes. The plug may even appear to be rusty looking. Normally this condition is harmless, though excess build-up can cause misfiring. Ash-fouled plugs can be cleaned, gapped and reinstalled.

A plug that shows a rusty material build-up, frequently appearing muddy or wet, indicates water that has passed into the cylinder via a blown head gasket or cracked water jacket. The major component should be repaired and the plug replaced since such rust accumulation is very hard to remove. Such a fouled plug would cause a noticeable miss in the affected cylinder.


You can easily check the condition of your distributor cap yourself. This is done by removing the retaining screws (usually two), or the spring clips that hold it (there is no need to take the plug wires off the cap.) Depending on the number of cylinders in the engine, there are metal poles on the upper inside of the cap. They should be inspected for accumulations of carbon and rust, then sanded lightly to clean the surface. The metal pole in the middle (rotor contact pole) should be examined for cracks and burn marks; it can be scraped lightly with a fingernail file to improve its contact surface. The inside of the cap should be wiped with a rag and a bit of alcohol, then scrutinized for hairline cracks (known as carbon cracks). These minute cracks cause shorts and misfiring, and if the cap has them, it should be replaced. Distributor caps have a habit of misfiring in moist or rainy conditions since moisture can accumulate on the inside of the cap causing shorting and hard-starting. Moisture-laden caps can crack suddenly when they are heated up or they can become brittle in very hot engine compartments.

Rotor—Depending upon the make of the car, the rotor will be the plastic knob or disk that sits directly over the distributor shaft. There is no need to remove it but it should be inspected for carbon cracks, and the metal contact can be cleaned like the cap poles.

Be sure to have the rubber “0” ring on the underside of the distributor cap replaced (if so equipped) before the cap is reinstalled. Do not over-tighten the distributor mounting screws and in the case of the snap clip variety, make sure that both clips are snug and snapped into their grooves.

Points—Typical of standard ignition is a set of ignition points and a condenser located on the distributor just under the rotor. The points either have a fixed gap (factory preset) or they can be adjusted in thousandths-of-an-inch.

By using a small screwdriver or pick, the points can be opened. The inside surface of the small contact disks should be relatively clean and smooth with no burn marks, pitting, or corrosion. The disks might have a slight sooty appearance and this can be etched away with a small fingernail file. When the contact points are closed the two opposing breaker contacts should be flush and aligned properly. If not meeting flush, the points could be sprung or out of adjustment or a bad distributor part might be the cause. If the points are adjustable, loosening the retaining screws can misalign them and change the gap (dwell degrees). The engine probably wouldn’t start because the firing se quence is disrupted. Thereafter they would have to be reset (re-gapped) to the manufacturer’s specification.

Condenser—The condenser can be either internally mounted (next to the points) or externally mounted somewhere on the distributor body. It is a small cylinder about the size of a nickel in radius and about an inch long. It has a small wire leading from it that's attached to the terminal on the distributor. It stores electrical energy and blocks the flow of direct current. It works in conjunction with the points and is always replaced along with the points in a minor or major tune-up. A visual inspection of it can tell you little, if anything. It is usually diagnosed, along with the condition of the points, on an oscilloscope.


Plug wires rarely last the life of a vehicle. They become rotted, burned, frayed and damaged by other means. Defective wires will cause misfiring by permitting the high tension ignition current to jump through damaged insulation to some part of the engine. In many cases the sound of a “snap” or repeated “clicking” noise of the jumping spark can be heard when there’s a break in the wire. Damaged plug wires that arc against another part of the engine can be seen in a darkened garage or at night with the hood up. The jumping spark will be seen as a miniature blue/white lightning bolt, accompanied by a snapping or clicking noise.

Overheating in any wire over a long period of time can cause in creased resistance and lead to misfiring. Mechanics can routinely check the resistance in plug wires by the use of an oscilloscope—this is done by examining the length of the firing line that appears on the screen.

One point can be argued against replacing the entire set of plug wires, and that's if only one wire is found to be faulty. You may request that only the bad wire be replaced; individual wires can be cut and custom-fit as a replacement. However, if your car has over 50,000 miles, and if the wires have never been replaced, it would be wise to replace the entire set because the other plug wires might be approaching a similar deteriorating condition. On a new vehicle, replacing one plug wire would certainly be justified.


Never touch or handle plug wires when the engine is running; the coil produces upwards of 40,000 volts and you’ll literally get the shock of your life.


The PCV valve is a device that allows amounts of burned exhaust gases to pass back through the fuel intake system for the purpose of being recycled. The valve has a ball check in it that frequently becomes stuck due to carbonized gum. It has to be cleaned or replaced regularly, preferably cleaned, since it's designed for permanent maintenance. On the other end of the PCV tube, attached to the inside of the air cleaner, is the PCV filter. The filter keeps most of the heavy burned exhaust gases from entering directly into the throat of the carburetor. It is a small fiber-like sponge and very inexpensive to replace.


Fuel filters have the same job as the air filter only they are designed to screen out rust, debris and other foreign particles in the fuel. When fuel filters become clogged, fuel delivery from the gas tank to the engine slows down. When this happens the engine “starves out,” stalling or quitting altogether. A general indication that a fuel filter is clogged is when your car bucks and cuts in and out as the engine runs momentarily out of gas. Congested fuel filters can also cause extreme back-pressure to build up in the fuel lines, leading to leaks that could ignite in the engine compartment. Fuel filters are not expensive and should be replaced routinely—every other minor tune-up or so. If you experience any of the above conditions, check the fuel filter first before you are sold a major tune-up.


The air filter should be replaced in a minor or major tune-up, although it may not need it every time. By removing the filter and shining a flashlight or bulb inside the ring, you’ll be able to see how clogged it's ; if light shines through most of the filament it does not have to be replaced.

If you drive on a lot of dirt roads or in the desert, you should replace and check the filter more often. A good habit is to rotate the air filter in the case so as to offer a fresh and clean side nearest to the air intake snorkle. This can be done every 5,000 miles and serves to get the most service out of the air filter.

For such a simple and uncomplicated part, the air cleaning element is very important to engine performance. A clogged or dirty air filter richens the air/fuel mixture (less air or more fuel) and can increase fuel consumption as much as 10%. Tests have revealed that 1/3 of all vehicles operating on the road today have air filters in need of replacement. A dirty air filter that does not allow fresh intake air into the carburetor can lead to hard-starting and engine stalling.


Along with the ignition parts that are commonly replaced in a minor standard tune-up there are a few adjustments that the mechanic will or should make. After replacing all parts, he should set the distributor timing, if it's needed, on cars equipped with standard ignitions. This is done with a timing light and takes about five minutes.

The next procedure will be to adjust the carburetor (if your car has one); the air/fuel mixture (lean or rich mixture) is adjusted for best rpm idle according to manufacturer’s specification.

The very last setting will be that of the idle speed. This the specified setting of the engine rpm’s at idle while in park or neutral, and in drive with the brake applied. The settings are specified by the manufacturer.

So what we have here are the parts and adjustments normally associated with a major tune-up on a vehicle equipped with standard ignition.


A mechanic should replace all the spark plugs making sure that they are properly gapped; install a new set of breaker points and condenser, making sure that the points are adjusted; replace the rotor (which can be a push-fit type or screw-on type); then make the normal adjustment of the timing and carburetor. This procedure is quite easy and should not take more than an hour-and-a half—two hours tops.


Electronic ignition systems have been around since the mid-1970s. They have become standard equipment on U.S. -built cars, and most of the foreign makes now carry this type of ignition system. You probably have electronic ignition in your car now. It is nearly maintenance-free aside from some components that are replaced due to electrical shorts or wear. The problem is too many people are unaware of this fact and are sold service usually required with a standard ignition tune-up. What they don’t realize it that this service is not necessary, or even possible, with an electronic ignition tune-up.

Along with the increased proficiency of new spark plug designs, electronic ignition systems can extend the life of a tune-up threefold. There are several system types in use today. Except for physical appearance, parts placement and the names used to identify different components, there is surprisingly little change from one sys tem to another.


There is a lot that can go wrong with electronic ignition, but this doesn’t happen as frequently as one would think. Troubleshooting electronic ignition components is very difficult for the layman or back yard mechanic.

It always requires a test scope to determine and pinpoint such faults in a system of this design. A qualified mechanic must use several procedures or “go, no go” operations to find a faulty part. An engine can miss, die, or not start at all when a major component in the electronic ignition system is at fault. If an engine will not start at all, it's a good bet that the fault lies with either the carburetor or the electronic ignition system. But I have seen electronic systems last over 60,000 miles of operation. In several cases owners have claimed that they have never had a part replaced in this system except for spark plugs. On most cars with electronic ignition, I’ve seen the distributor cap replaced more often than any other internal part. And even this is not as necessary a replacement procedure as it's with standard ignition.

So what do we have here? Well, we have a nearly fail-safe system (as opposed to the old standard type) that's durable and seldom breaks down. When it does, it's affordably replaced or repaired.


It’s conceivable that a subsystem component or a sensor could go bad, ca using a no-start, hard start, or rough running engine condition. Therefore, you should be hesitant in believing a mechanic/ technician who tells you it looks like your “computer” is bad, especially if the other subsystems have not been checked out first.


The electronic tune-up should be comprised of everything that's included in the minor standard tune-up, minus a few parts.

However, all standard adjustments should be included: timing, carburetor (mixture and idle), a fast idle choke adjustment, or any other necessary carburetor adjustment. If your car has electronic fuel injection, then this should be adjusted and checked as well. A mechanic should know, via the pattern on the oscilloscope, whether your electronic ignition components are in proper working order, as well as the condition of your plug wires, vacuum lines, coil output, battery and charging condition. You should always have your spark plugs replaced. It is quite possible, depending upon the repair facility, that a valve adjustment will be part of the minor tune-up, although it's generally part of the major tune-up.


A major electronic tune-up should include everything in the minor tune-up plus some added services and parts.

The distributor cap should be replaced and a valve adjustment per formed. All the necessary carburetor adjustments should be made, unless your car has a sealed or capped system in which the carburetor can't be adjusted. On a sealed carburetor, it's often necessary to remove the carburetor from the car to take off plastic knobs that have been installed over the adjustment screws, and this service might cost extra.

All filters should be replaced; fuel, air and PCV. Your car might have two fuel filters: one at the carburetor, and an inline canister type filter located between your gas tank and the fuel pump. Filter replacement will depend on what make or type automobile you own.


The complexity of electronic fuel injection systems and electronic engine management systems makes it easy for the mechanic to start tossing around auto jargon that sends your head spinning as you sign a hefty repair order. First of all, the engine computer and fuel injection system should be fully covered under regular and extended warranties. Be sure to check for that first.

Second, remember that a mechanic (especially a dealership mechanic) will have in his inventory a duplicate working computer that can be snapped onto your car’s system to determine if your computer has shorted out or isn’t functioning. If the problem re mains, then something may be wrong with components in the system.

For fuel injection and computer diagnosis, you should definitely go to the dealership. Don’t mess with these systems yourself. You could damage the system and void any warranties.


Almost all new cars today have fuel injection. If your car does not have a carburetor, it has a gasoline or diesel engine with a fuel injection system. They are just too complicated to work on for the average layman—even testing the skills of a highly trained mechanic.

Service—It’s true that fuel injection systems are more costly to repair than carbureted types, but they are here to stay, so you’ll have to learn to live with the high price tag charged by dealerships and specialists. As far as service is concerned, my advice is to go to the dealer or a specialist only. The sophistication of these systems is often way beyond the gas station, department or chain store mechanic.


The Rush Job—Not all, but some repair mechanics have a nasty little habit of rushing an electronic tune-up. What can happen? It’s mostly what doesn’t happen and what doesn’t get done.

In short, in the case of a small compact car, he could glance at the oscilloscope, screw four spark plugs into it and go for coffee. No adjustments, no inspection, no road test, no valve adjustment, no filter re placements, no cap or other services and so on. You’d pick up the car and drive away none the wiser. How could this be?

Well, it was probably running pretty well when it came in. For instance, the timing was dead on, the carb mixture and idle speed checked out, the firing line (on the scope) looked okay, and it was running smooth enough so a valve adjustment wasn’t really necessary. The fluid levels in the engine compartment were close enough so why bother?

It took the mechanic about 10 to 18 minutes to do this tune-up because he buzzed the plugs out with a pneumatic driven wrench and replaced them just as fast.

The scope hook-up took about two minutes flat with about 30 seconds to read three different test patterns. The only adjustment he might have been forced to make would be the idle speed since it would normally change with the inclusion of four new spark plugs. This adjustment would take about three minutes. Elapsed time: about 25 minutes, give or take. What was the repair. facilities cost for this tune-up? Maybe $3.00 for all four plugs, around $14.00 for the mechanic’s labor. So $18.00 is what their cost is. What was the total on your repair invoice? Anywhere from $120.00 to $180.00. Did you get your money’s worth? I don’t see how it adds up. After all, you waited all day for your car.

In a shop where mechanics are paid a commission on parts and a bonus for extra cars over a certain quota, this quickie type of tune-up happens often. Replacing just the plugs usually solves a culprit miss, or a rough running engine. New plugs are also great for showing a marked improvement in fuel economy and engine performance.

Hood-Up Syndrome—The above example also explains the “hood up” syndrome, a case where you find that your car is left unattended in a stall with the engine hood up and no mechanic can be seen working on it. This is probably due to the fact that the mechanic finished very quickly on your car and wants to leave the impression (in case you check), that there is still something to be done on it. Only he is out of sight working on his next ticket. This facade is very common at dealer ships where the customer is known to be waiting nearby for the release of his car.

Misdiagnosis—Let’s say that you take you older car, (one equipped with a carburetor) into a service center because the engine is running rough (missing), or running sporadically. The mechanic tells the manager that a tune-up will set things right, so the manager gets the okay from you (your signature) on the repair invoice.

Four hours later you get a phone call from the manager who informs you that your car took the tune-up all right, but he recommends that you rebuild or replace the carburetor. In fact, he tells you that a new carburetor (or a rebuilt one) will cost you less than having yours torn down and worked on. His reason for this added repair? He might say that the “carb is on its way out anyway so there wouldn’t be any harm in taking care of it now.” So he wants your verbal okay over the phone difficult to take off than others. But the mechanic that tells you he needs to charge you an extra $35 to pull your carburetor completely off the vehicle to get at the caps is pulling a scam. Even though the procedure is recommended by shop repair manuals, every mechanic I know has learned how to do this without pulling the carb. Most of these caps can stay off for good—they are only put there to ward off tampering by an unskilled customer who wants to adjust his own carburetor.

The Cover Up—If a mechanic can’t tune your car to the point of a smoothly running engine by following the exact tune-up specifications (by the book), he is likely to make a few of his own “hot rod” adjustments to get the car running better. Two of the easiest ways to give a car more power or mask a rough running engine, is too richen the carburetor mixture and advance the timing a few degrees.

This will “cover up” his mistake. And you probably won’t know the difference until you try to have a smog check, or check your fuel mileage. You’ll fail the smog check, and your fuel mileage will de crease.

Then the bad adjustment would have to be readjusted at extra expense (not to mention a rough running engine that the smog mechanic now has to repair because the original tune-up was botched). Insist that your car be set to “manufacturer’s specifications,” the condition in which your car was designed to perform at its peak. If the car is set to “specs” and still runs poorly, the mechanic has not done the job properly.

Mileage From Heaven—Don’t be surprised if you pull out of a service center having just had a tune-up, and discover during the next week that you are getting miraculous gas mileage.

What they have done is over-inflate each one of your tires from five to seven pounds (over specifications), to make it appear that their tune-up was so good that you are now saving money because of their superior workmanship. A vehicle’s tires can be overinflated without any notice able wear. Overinflated tires use less friction when rolling over the ground. The instant result is increased fuel economy due to over- inflated tires, not the tune-up.

Do this before a tune-up as a safeguard: check and adjust your tire pressure via your owner’s manual recommendation. If after the tune up your tires are higher in reading, it means that you’ve been duped. Also, your car might ride a little rougher after this sham has been done. I know of several major tire and department store repair shops who are using this device today. It is one of the newest tricks in their stable!

Protecting Yourself—How can you protect yourself and be assured that you are getting maximum service and care? There is a neat little trick that can be used when you visit an auto repair facility for a tune-up, standard or electronic. You simply type or write a list of tune-up procedures you want performed on your car and present them to the mechanic. These request services are actually part of the tune up, and when the mechanic reads the request list, he will recognize that you are a stickler for detail and thoroughness. The list that works best has empty boxes in the right margin that must be manually checked off by the mechanic. Is this type of “list strategy” out of the ordinary? No. That doesn’t mean mechanics like them, but they will usually follow the directions and check off the boxes. What follows is an example of a request list, or what may be termed an “action item list.”

1. Compression check.

2. Engine scope and diagnosis.

3. Replace spark plugs and gap new ones.

4. Replace cap, rotor, or other electrical component that's obviously bad.

5. Adjust valves if needed.

6. Check fuel and air filters—replace if needed.

7. Complete carburetor adjustment, idle mixture, speed, choke setting (fast idle).

8. Inspect vacuum lines for wear and leaks.

9. Clean PVC valve.

10. Report spark plug wire continuity.

11. Perform L.O.F. if needed and attach sticker to door jamb.

12. Please road test.

13. Would you please save old parts and bag them. Include guarantee.

Signed __________


Of all the elements in an engine, replacing the air cleaner filter/s one of the easiest. If you want to save yourself some money, go to your nearest local parts store outlet, plunk down the five or six dollars, and then just unscrew the nut (generally a wing nut), remove the lid and swap the old for the new. This way you’ll save the mark-up and labor charges from the repair facility. Just be sure you tell them you don’t want an air cleaner when you go to get your car tuned up.

You can make up your own list that's specially tailored for your particular make and year of automobile. Consult your owner’s manual for the prescribed periodic maintenance chores and services. You will hand this list to the manager, who will in turn clip it on the work order invoice. You could tell the manager that you are conscientious about keeping

you are thinking about selling or trading in the vehicle and you realize that maintenance documents are in your financial favor when about to sell or trade. The manager will perfectly understand this request because it makes good common sense.

Or you can plainly state that you are a perfectionist (with apology) and would like to have the work done right. Whatever excuse you use, you will find that this list works with a tune-up better than any other auto repair service. Make copies of your list so you can use a fresh one every time.

Special Deals—What if you came into a service center for a routine brake inspection or a battery charge and the mechanic told you that you needed a tune-up? What if he says that it’s your lucky day because they just happen to be running a special and if you don’t take advantage of it now, the price is sure to go up next week? Let’s also assume that your tune-up is not due for another 10,000 miles and your engine is presently running as smooth as silk, good fuel economy, etc. Should you take advantage of this incredible one-time offer? I certainly wouldn’t. Paying for tune-ups is not like shopping for groceries in which you take advantage of a deal because it's posted, spread by word of mouth, or advertised.

Women should be particularly on their guard with this tactic, because managers like to appeal to their money-saving, bargain- shopping senses and will liken his offer to a K-Mart blue light special that you can’t resist.

Managers will prey on a different sense when dealing with a bachelor. Along with the implied “saving money” theme, a manager might try to appeal to a man’s need for more power and performance, especially if he has a sports car. If you hear this one, you know you’re being had because a tune-up, either major or minor, will not add horsepower or torque to the engine. A tune-up is a maintenance procedure that keeps the engine running at maximum efficiency, at its stock, peak horsepower and torque output. In other words, it just keeps it running as closely as possible to the way it did when it rolled off the showroom floor. Tune-ups are not “modifications,” and don’t deliver large performance gains. Don’t fall for this appeal to your sense of machismo.


  • Regularly scheduled tune-ups provide the best performance and fuel economy. Regular tune-up service can also ward off breakdowns and car trouble in adverse weather.
  • Your owner’s manual is the best reference source for knowing how often to perform standard or major tune up service on your car.
  • Before a tune-up, have the ‘mechanic verify that you actually need one. Make sure that a surge, engine miss, stumble or hesitation is not caused by some other area that can’t be fixed with a tune-up. For instance, you might have a vacuum hose disconnected, which is causing an engine surge. Don’t automatically ask for a tune-up; ask that they “fix the miss or surge.” Try to narrow the problem down instead of generalizing.
  • Remember that cars with electronic ignition don't have to be tuned as frequently as the older standard ignition models. Some cars can go 30,000 miles and more before an electronic tune-up is needed! Consult your manual.
  • If you don't adhere strictly to your owner’s manual for tune-up schedules, then use some common sense. Trying to stretch every last mile out of a tune-up (procrastination) will eventually produce hard-starting, bad performance in wet weather and poor fuel economy. If you notice any one of these three signs it means that you have gone too far between tune-ups and one is needed.
  • Find out exactly what is included in a standard or major tune-up from your owner’s manual, then compare that list with what a repair facility offers. Go to the facility that most closely follows the guidelines set forth by your owner’s manual.
  • If your spark plugs are being replaced, make sure they are the proper heat range. If your driving habits are exclusively high speed and long distance, a cooler range plug can be used. If you always travel in congested city traffic, a hotter range plug is best.
  • Remember that old spark plugs can tell a story about what condition your engine is in. Have the mechanic explain to you any abnormal wear pattern or condition of any of your old spark plugs. For instance, an oil fouled plug warns of excessive oil consumption (internal engine problem).
  • Use a tune-up list approach when going to a repair shop for a tune-up. Make sure the manager takes the list and passes it off to his mechanic.
  • For fuel injection service make sure that the repair facility you approach has the proper training and diagnostic equipment to do the work properly. Department stores and quick stops are not good candidates for this service—go to dealerships and specialty shops who employ mechanics certified in this area of repair. Do not attempt to work on fuel injection systems yourself.
  • The Association of Diesel Specialists do work exclusively on Diesel cars. They carry the ADS logo and their mechanics are certified for diesel work. This is the only place to take your diesel powered vehicle if you are unsure of the proper repair facility.
If you can, stay around and watch and monitor the tune-up. Presenting a face with the car works very well with tune-up service. Your visual presence keeps mechanics on their toes and less likely to pull sneaky scams.

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