Do you know your way around under the hood of your car? While not as critical as it used to be, checking under the hood periodically can head off problems before they become costly. Today, with self service gas stations everywhere, often the only way you will get it done is for you to do it yourself.
Start by reading your owners manual. There will always be a section on under hood checks. Keep a pair of old gloves and a roll of paper towels in the trunk
First, a word about safety. Read the safety warnings in your owners manual and any safety warning stickers that may be under the hood.
If the engine has been running for any length of time, there are areas under the hood that can be very hot. Except for checking transmission fluid level, all checks should be done while the engine is turned off. If the engine is running, do not put your hands near any belts or fans. If you are not comfortable with touching a hot or running engine, then just do the checks that can be done with the engine cold and turned off and have someone else do the rest.
The following items should be checked periodically:
Regular oil changes are the best way to ensure longer engine life. If you frequently take short trips where the car doesn't always completely warm up, then they are even more important because acid and moisture buildup does not have a chance to burn off.
When an oil change service is referred to as an "Oil, Lube & Filter," the "lube" is a chassis lubrication where the mechanic applies grease to various steering and suspension joints under the car. Most modern cars are manufactured with sealed-for-life joints that do not have grease fittings; however if any of these parts were replaced, the new parts probably do have lubrication points and must be greased to prevent premature wear. If you have had parts replaced, make sure that the mechanic knows it or he may overlook them.
Doing an oil change yourself does not require much skill, but crawling under a car and having oil drip down your sleeve is hardly worth the $5 or so that you might save. Then, you have to deal with the old oil and filter. I could think of a more productive way to spend a Saturday afternoon.
Environmental pollution, not to mention fallout from birds, will take its toll on your car's finish. The best way to protect the finish is to keep it clean. This is especially true during the winter months in the snow belt where salt is used to keep the roads clear. While today's cars have very durable finishes, they are susceptible to prolonged exposure to corrosives. I have seen new cars sitting in a dealers lot for two or three months that had to be refinished because the paint became etched from bird droppings.
If you have retractable headlights, make sure you clean them regularly. They are often overlooked when having your car washed.
A car wash will keep your car clean with a minimum of time and effort. The brushes they use are safer on a car's finish than they used to be and many are brushless. I don't ask for wax at car washes because it may coat the windshield and cause the wipers to streak, but then I hand-wax my car twice a year. If you decide to wash the car yourself, use products that are safe for car finishes.
Regular waxing will keep a car looking new for many years. A ten-year-old car that has been waxed twice a year will probably have a better shine then when it was new. It will also command a higher resale value and be easier to sell.
If rain water does not bead on the painted surfaces of your car, it's time to wax it. How often you have to wax your car is dependent on the type of wax you use and how good you want your car to look. Some of the new synthetic waxes will last more than a year.
Obviously, there are two ways to get the car waxed: have it done by someone or do it yourself. If you don't mind spending about $100.00, check out an auto detailer. They will clean the entire car inside and out, cleaning and waxing the body and shampooing the interior, right down to using a toothbrush to clean the seams in the dashboard. They will deep-clean the wheels and tires and make sure they remove any wax residue around the nameplates and emblems. Check with your local car wash or look in the Yellow Pages under "Automobile Detailing".
If you decide to wax the car yourself, make sure you start with a clean car and never work in direct sunlight on a hot day. Before you start, run your hand over the surface, it should feel smooth like glass. If it feels rough or gritty like there are bits of sand embedded in the paint, then you should first use a non-abrasive cleaner to clean the paint before waxing. One of the best methods that I have found uses clay to smooth the surface. Products such as Clay Magic & Maguire's Clay Detailer work beautifully with amazing results. Make sure you only use products designed for automotive finishes and follow the instructions on the container. After you finish waxing the car, you should go over the entire surface to look for wax residue, especially around trim and body seems. A tooth brush or Q-tips work well for this. If your car has black trim, try to keep the wax away from it. Some waxes may leave a chalky film on dull black trim, such as rubber and some plastics, that can be hard to remove. Look for products that are made for cleaning black trim. I found them to work well and really let the black stand out.
Before beginning the job, examine the paint closely for chips and scratches and touch them up. Touch-up paint is available at most auto supply stores for the most popular paint colors. If you can't find your color there, check with your new car dealer. If they don't have it you may have to go to an auto body supply where they can match any color you might have (for a price). I always ask for a tube of touch-up paint when I buy a new car. That tube will usually last five or more years if you only use it for chips and small scratches and keep it covered.
Wheel Alignment: To find out if you need an alignment, first check each tire and look for uneven wear patterns. The problem with this method, however, is that if you can see a wear pattern like the ones listed below, it may be too late to save that tire. This is why it is a good idea to have your alignment checked periodically.
At each tire, take a coin and insert it in the tread at the inside, center and outside.
If the tread is deeper on
the edges than in the center, the tire is over inflated. 
If the tread is deeper in
the center than the edges, the tire is under inflated.
If the tread is deeper on
one side than the other, have your wheel alignment checked soon.
Run your hand back and forth
across the tread, being careful not to cut yourself on any debris or exposed steel
belt wire. If the tread is smooth in one direction, but jagged in the other you
have what is called a "saw-tooth" wear pattern which is caused by a toe-in
problem. Have the alignment checked as soon as possible as this condition causes rapid
tire wear.The first two conditions do not call for a wheel alignment but the second two do. If these wear patterns are pronounced, you should replace the tires or move them to the rear before aligning the car. Ask your alignment specialist to be sure.
Another indication of an out-of-alignment condition is a car that continuously drifts or pulls to one side of the road when you let go of the wheel. A car that is hard to keep in a straight line without constant steering corrections is also a candidate. These conditions may or may not also contribute to premature tire wear.
A wheel alignment cannot be done on a car with loose or worn front end parts. The technician will first check for worn parts and inform you of any problems before beginning the alignment.
The best type of wheel alignment is a four wheel alignment. Many cars today have adjustable rear alignment settings, but even for cars without adjustments in the rear, a four wheel alignment will allow the technician to identify any rear tracking problems and compensate for them with adjustments to the front.
After the wheel alignment is finished, you should drive the car on a straight and level road and check that the car goes straight and that the steering wheel is in the proper position with the spokes level. If you notice a problem, take the car back and have the technician drive it and fine-tune the alignment settings.
Wheel Balance: Out-of-balance tires will cause a car to vibrate at certain speeds, usually between 50 and 70 mph. A tire is out of balance when one section of the tire is heavier than the others. One ounce of imbalance on a front tire is enough to cause a vibration in the steering wheel at about 60 mph. To balance a wheel, the technician will mount it on a balancing machine which spins the wheel to locate the heavier part. He will then compensate for the heavy part by attaching a lead weight on the opposite side. Many people are pleasantly surprised at how smooth their car drives after balancing all four wheels.
Most high quality tires will hold their balance fairly well and go out of balance very gradually. If you notice a vibration that wasn't there the day before, it is possible that one of the lead balancing weights fell off. If you feel the vibration mostly in the steering wheel, the problem is most likely in a front wheel. If the vibration is mostly in the seat, the problem is in the rear.
For those of you who are very sensitive about vibrations and your shop can't seem to get that last bit of vibration out, check to see if you have locking wheel lugs. Some locking lugs are about 1.5 ounces heavier than the other lug nuts which translates to about 1/2 ounce at the wheel rim. Try putting a 1/2 ounce weight opposite the locking lug and see if it helps.
On front wheel drive cars, it is especially important to rotate your tires periodically because the front tires wear faster than the rear. Uneven tire tread thickness, front to rear, will give you uneven braking and poor handling, especially in the rain. If you don't rotate the tires, you'll wind up replacing them two at the time, which means you'll always have uneven tread thickness. Replacing tires in a matched set of four will keep the handling and braking traction of the car balanced.
On certain cars, you may experience an additional problem when you do not rotate the tires: tire noise or humming on smooth roads. If you notice a humming noise, check the rear tires for a "saw-tooth" wear pattern by running your hand back and forth along the shoulder of the tire tread. Be careful not to cut yourself on debris or exposed steel belt wire. If it feels smooth in one direction, but jagged in the other, you may have found some of your noise. This condition happens on some front wheel drive cars with tires that have tread blocks on the shoulder of the tire. Rotating this tire to the other side of the car should even out this type of wear and quiet down the humming. Check your owner's manual for the proper rotation method. Most front wheel drive cars require the following rotation method:
Warning: If you have directional tires such as Goodyear Aquatreads they must never be crossed over to the other side of the car. You can tell by the fact that they will have a clearly marked arrow on the sidewall showing the direction of rotation.
Prior to 1975, a tune up consisted of replacing the plugs, points and condenser; then setting the timing, adjusting the carburetor and checking or replacing the cap, rotor, wires, gas filter, PCV valve and a host of other replaceable maintenance items. Today, computerized cars with electronic ignitions eliminate the points and condenser and adjust themselves at the rate of ten times per second.
The only items that need to be replaced on a regular basis are the spark plugs and certain filters such as the air filter, fuel filter, and some emission control filters. When the spark plugs are replaced the technician should check the ignition wires and the cap and rotor if your car has them. Some new cars are even equipped with platinum tipped spark plugs some of which last for 100,000 miles!
Corrosion inside the cooling system can cause failure of various components such as the water pump, thermostat, radiator cap and heater control valve. The best way to prevent corrosion is to flush the cooling system periodically and replace the antifreeze. If the car has more than 60,000 miles, you should also consider replacing the thermostat and radiator cap preventatively. Some modern engines cannot tolerate even a single bout of overheating without incurring serious damage like a blown head gasket. So everything you can do to prevent overheating is a plus.
Certain engines with overhead camshafts have timing belts that have a limited life span. Car makers use belts instead of more durable chains because chains are noisier and cost more to manufacture.
When a belt fails, it can cause serious engine damage bending valves and breaking pistons. At worst, you will need a new engine. At best, you may be stranded by the side of the road. Timing belts fail without warning so your only protection is to change the belt at the recommended intervals. Timing belt replacement is not a cheap job but it is less costly than the alternative.
There are a number of replaceable filters in a car. They are listed in your owners manual along with recommended replacement intervals. If you live in a dusty area or in a big city, then you should replace them more frequently. The following filters are common to most cars
Check your owner's manual for any other filters requiring servicing.