Repair 7

The spark plug is a vital component in the operation of an internal combustion engine. As the name implies, the spark plug creates a spark that ignites gasoline inside a combustion chamber. This creates the energy to force the piston downward. The movement of the pistons gives the engine its power. To make sure that the engine operates as smoothly and efficiently as possible, it needs to be tuned up on a regular basis. An important part of that tune-up is removing and replacing the spark plugs, a process thats fairly straightforward.

Instructions

1

Make sure the engine is cool. The spark plugs are one of the hottest components of an engine.

2

Clean any dirt or debris from around the base of the plug to keep dirt from falling into the combustion chamber. Use compressed air to blow debris away if it is available.

3

Use your owners manual to find the spark plugs. Most engines have spark plugs wires that lead to the spark plugs. Newer engines may have individual ignition coils mounted over the spark plugs.

4

Remove the spark plug wire from the spark plug by pulling on the rubber boot. Do not pull on the wire itself. If equipped with ignition coils, remove the ignition coil mounting bolt to remove the coil and reveal the spark plug.

5

Install the spark plug socket on the socket wrench. You may need to use a swivel joint or a socket wrench extension to reach spark plugs in the back of the engine.

6

Place the socket over the spark plug and turn the socket wrench counterclockwise to loosen the spark plug. Use steady force to remove a stubborn plug. Too much force can shear off the top of a spark plug or strip the threads.

7

Continue to turn the wrench until the spark plug comes out of the hole. Once loosened, you should be able to remove it by hand.

When a vehicle engine is reluctant to start, it often means that the spark plugs need changing. Like many automotive components, spark plugs dont last forever. A common malfunction is a wet spark plug. According to AA1Car.com, this occurs when the spark plug fails to fire, or fouls out. This can be caused by a number of variables, such as engine flooding, or excessive moisture build up.

Engine Flooding

Failed vehicle starting attempts eventually lead to wet spark plugs, according to E3 Spark Plugs. This happens when drivers attempt to start their vehicles multiple times without success. This can lead to engine flooding, which in turn can soak the plugs so theyre unable to form any kind of spark to start the engine. This often happens in cold weather conditions, when spark plugs that are previously worn or fouled require a higher voltage to ignite the engine. In this case, the best thing a driver can do is either wait for the plugs to dry, or remove the plugs and clean them off.

Injector Leaks

Wet fouling is less common on modern fuel-injected engines, but can happen due to a number of mechanical failures, states AA1Car.com. One example is a leaking cold start injector. This would lead to the creation of a rich start up mixture in the engine compartment that would cause the plugs to foul.

Worn Piston Rings

In older vehicle engines, worn piston rings or excessive cylinder wear often lead to wet fouling, states Mopar Magazine. This could result in the release of excess oil or gasoline into the engine compartment, which could prevent a spark from forming during an ignition attempt. Wet-fouled spark plugs can be cleaned and re-installed to work effectively.

The engine spark plug, whether used in automotive applications or commercial and industrial use, serves a straightforward purpose. It has the job of sealing off the combustion chamber while generating a high voltage to spark an explosion of atomized fuel and air. Spark plugs come in many heat ranges, sizes and construction materials, which have reference numbers. Two Champion spark plugs, such as the RN9Y and the RN9YC, have similar designs except for an additional identification number.

Spark Plug Description, Letter "R"

The RN9Y Champion spark plug has four reference numbers that describe its specific application. The first letter, "R," describes the special suppressor shielding construction of the plug, which identifies it as a resistor-type plug, used for suppressing radio and engine-noise static. The RN9YC spark plug is no different in this respect.

Letter "N"

The "N" describes the physical construction of the outer shell. In this case, the outer shell has a 14 mm thread size, a 3/4-inch reach, or depth into the combustion chamber and a 13/16-inch hex bolt design. The RN9YC spark plug is the same as the RN9Y in this aspect.

Numeral "9"

Typically, Champion spark plugs that have numeral designations between 1 and 25 have application use in automotive and small engines only. The number "9" falls within this range, excluding it from use in larger commercial and industrial engines. The RN9Y and RN9YC spark plugs are identical in this respect.

Letter "Y"

In a Champion spark plug, the letter "Y" on the RN9Y spark plug refers to the firing-end design of the spark plug electrode. In this case, the "Y" indicates that this spark plug uses a standard projected core nose, one of the most common configurations. Electrode length determines the heat range, and in some cases, the depth of the plug inside the combustion chamber. The "Y" on the RN9YC spark plug means the same thing.

Letter "C"

The extra "C" for the RN9YC spark plug identifies it as a copper-core plug, which makes the core construction material different from the RN9Y spark plug. The electrode center contains an extruded copper core that promotes better heat-range distribution. This allows for longer plug life. The copper electrode element also resists corrosion and contamination better than the standard design. The RN9YC spark plugs have useful applications when used on HEI (high energy ignition) systems that require better quality and longer plug life.