IDENTIFYING AND CORRECTING MECHANICAL PROBLEMS

LESSON #10

    You need to be aware of symptoms that can alert you to the need for maintenance work on your car.  We are not in any way trying to make mechanics of you, but want you to have the awareness of and skill in the preventive maintenance any of you can do.

    Read chapter 17 again which informs you about the warning lights in the dash, how to check that they are working properly, and what they mean when they come on at certain times.

    Two basic things will alert you to a need to have the front wheels aligned.  If the car pulls to one side or the other and the tires are evenly matched and properly inflated, you probably need wheel alignment.  If there is noticeably uneven wear on the front tires on the edges of the ribs or the tires feel "sharper" one way when you rub your fingers across the face of the tire, you probably need wheel alignment.  You should take your car into a service shop where they do alignment, and have the front end checked out.

    When the wheels "bounce" or "vibrate", usually at highway speeds, it is normally because one or more tires are out-of-balance.  It is hard on the tires and can be hard on the car if you continue to drive with the out-or-balance tires.  The car should be taken to a tire shop where the tires can be balanced.  Additionally, vibrations can be caused by other problems such as a worn u-joint in rear wheel drive cars, so any time the is a noticeable vibration in the car, it should be taken to a tire and/or service shop so the problem can be corrected.

    On most cars when you turn on the turn signal and the dash turn signal indicator light comes on but it does not flash, it usually means you have a burnt out bulb.  With the turn signal on, check the front and back bulbs to see if they are lit.  If a bulb is out, you could probably change it yourself on most cars.  If the dash turn signal indicators come on for both sides but do not flash, and all four bulbs light, it probably means the flasher unit is not working and needs to be replaced.  On most cars this is also an easy element to replace if you can find it.  It is located under the dash in different positions.  Most cars have two flasher units, one for the turn signals and one for the four-way flashers.  Be sure you have the right one if you replace one or the other.  If replacing a bulb or flasher does not correct the problem, you need to take your car into a service shop.

    There are several indications when your car needs a tune-up or at least attention to some part of the ignition or fuel/carburetion systems.  Some of them are rough idling; the engine dying periodically; a hesitation when attempting to start out or accelerate when moving; the engine backfires; the engine misses, especially at higher speed or when accelerating, the engine is hard to start when cold, or when hot, or all the time; the check engine light comes on on the dash.  The ignition and carburetion systems on most modern cars are so complicated now that correctly diagnosing and correcting the problem usually requires highly technical equipment and trained personnel.

    When you do preventive maintenance checks under the hood, you should include an inspection of your battery.  More and more new batteries have the "green eye" and are sealed so no water ever needs to be added.  It's a small round glass on the top of the battery.  When you look straight down into the eye and it is green, it tells you the battery has a full charge.  If it is not, you need to have the battery checked.  If it is good but has the low charge, then the charging system in your car should be checked.  The same is true if the starter only turns the engine over slowly, especially if that happens basically only the first time you start your car each day.  For older batteries, they need to be checked periodically for proper water level.  As long as water can be seen above the plates (vertical cardboard-like material), the battery is O.K.  However, water should be added to the battery when the level drops below the "split ring" which is usually the full level indicator.  You also need to check for corrosion on the battery cables.  If you find corrosion, the easiest way to remove it is to pour boiling water over the terminals or put a solution of water and baking soda on the terminals and then rinse with fresh water.  Once that is done, the terminals should be tightened and protective fluid put on the terminals so that the corrosion does not start right back again.  Protective fluid can be obtained at most auto parts stores or some suggest using Vaseline.  It is important that whenever you do any work with a battery that you keep it and any solutions away from your clothes and wash your hands thoroughly when you are through.

    Brake system malfunctions usually have one or more of the following symptoms:  "mushy" brakes; the car pulls to one side or the other when the brakes are applied; the brake light in the dash comes on when the brakes are applied; you hear a scraping noise when the brakes are applied.

    Usually mushy brakes or the brake light in the dash coming on means low brake fluid in the master cylinder.  You could check that yourself and add fluid - but at the same time it should be determined why the brake fluid was low.

    When you hear a scraping noise while braking, it would usually mean the brake shoes need to be replaced.  You should get to a service shop soon as repeated application of brakes when the shoes are worn out is not only dangerous but can cause damage to brake drums and/or rotors to the extent that they would also have to be replaced and they are expensive.

    Periodically you should check the fluid level in the automatic transmission in your car (that is, if you have one).  The usual procedure is that the car needs to be completely warmed up, be idling, and be in park.  If the fluid is low, be sure to check on the procedure for checking the transmission in your car before adding - it can be very hard on an automatic transmission if it is overfilled.  The fluid should be bright red in color.  If it is dark in color or smells "burnt", the fluid should be changed soon.  If the transmission is shifting abruptly (jerking) or the opposite, slipping when shifting gears and the fluid is full, the car should be taken to a transmission shop to be checked.

    For most of the problems noted, the solution stated was to take the car to a service shop.  However, if you are mechanically minded and/or have been able to learn from parents or others, some of the items such as replacing brake shoes could be done by you.  Whenever you do your own work, you should check a manual for procedures and follow them and any precautions the manual states.  You should be careful about undertaking a job if you are not sure of what you are doing when it could cause a safety problem if not done properly.