Honda CRV/Odyssey 1995-2000 Repair Information

Spark Plugs

Print

A typical spark plug consists of a metal shell surrounding a ceramic insulator. A metal electrode extends downward through the center of the insulator and protrudes a small distance. Located at the end of the plug and attached to the side of the outer metal shell is the side electrode. The side electrode bends in at a 90° angle so that its tip is just past and parallel to the tip of the center electrode. The distance between these two electrodes (measured in thousandths of an inch or hundredths of a millimeter) is called the spark plug gap.

The spark plug does not produce a spark but instead provides a gap across which the current can arc. The ignition coil produces anywhere from 20,000 to 50,000 volts (depending on the type and application) which travels through the wires to the spark plugs. The current passes along the center electrode and jumps the gap to the side electrode, and in doing so, ignites the air/fuel mixture in the combustion chamber.

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Cross-section of a spark plug

SPARK PLUG HEAT RANGE



The spark plug heat range is the ability of the plug to dissipate heat. The deeper the insulator recedes into the body of the spark plug, the more heat the spark plug will retain and the hotter the plug will operate. If the amount the insulator recedes into the body of the spark plug is decreased, the less the plug will retain heat, and the cooler it will operate. A plug that absorbs little heat and remains too cool will quickly accumulate deposits of oil and carbon since it is not hot enough to burn them off. This causes carbon to build up on the porcelain insulator and the center electrode, creating an alternate path for the high energy electrical spark which eventually leads to spark plug fouling and consequently to misfiring.

A spark plug that absorbs too much heat will burn off deposits, however, due to the increased combustion temperature, the electrodes may also burn away more quickly and the excessive heat may cause pre-ignition or internal engine damage. Pre-ignition, also referred to as detonation, takes place when the combustion chamber gets hot enough to ignite the air/fuel mixture before the actual spark occurs. This early ignition may cause a "pinging", knocking or rattling noise during low speed acceleration or when operated under a heavy load condition, such as climbing a steep hill. Note that detonation can occur without being heard.

See Figure 2

Click image to see an enlarged view

Fig. Fig. 2: Spark plug heat range

The general rule of thumb for choosing the correct heat range when selecting a spark plug is: consult the vehicle's owner's guide or a spark plug manufacturer's supply catalog for recommendations. If only one heat range of spark plug is listed, use the recommended plug, and note the recommended spark plug gap. If more than one heat range of spark plug is listed, depending on operating conditions, evaluate the type of driving the vehicle is most often subjected to. If the vehicle is used for extended high speed, long distance travel for long periods of time, in warm weather, use the colder plug of the recommend spark plugs. If, however, most of the driving is stop and go, or the vehicle is operated in extremely cold climates, use the hotter of the recommended spark plugs. Usually, original equipment plugs are a good compromise between the 2 styles of driving, and most vehicles rarely need to have their plugs differ from the factory-recommended heat range.

REMOVAL & INSTALLATION



The spark plug replacement intervals for the Honda 1997-00 CRV and the 2.2L/2.3L Odyssey models is 2 years or 30,000 miles (48,000 km), whichever occurs first. The spark plug replacement intervals for the Odyssey models with the 3.5L V6 engine is 7 years or 105,000 miles (168,000 km), whichever occurs first. Refer to the maintenance interval chart located in the vehicle owner's guide or at the end of this section for additional items to be checked during the recommended maintenance services. During normal operation, The spark plug's gap increases as it wears. As the gap increases, the plug's ability to conduct a spark decreases, therefore the necessary voltage required to conduct a spark increases. The voltage required to jump the spark plug's gap at high engine speeds is about two to three times as much than at idle. The improved air/fuel ratio control of modern fuel injected engines combined with the higher voltage output of their ignition systems, will often allow an engine to run significantly longer on a set of spark plugs. However, the engine's efficiency most likely will drop as the spark plug gap widens and may decrease both fuel economy and power).

Before removing the spark plugs, label, or arrange the spark plug wires to ensure reinstalling them in the correct positions. On vehicles equipped with a distributor cap, mark the position of the spark plug wire for the number 1 cylinder. If for some reason the wires do become mismatched, the correct sequence can be easily determined by using the engine's firing order. The original equipment spark plug wires on Honda products are routed through well-organized guide clamps which can be removed from their mounting brackets while leaving the spark plug wires attached to the wire guides. Simply remove the spark plug wires from the spark plugs and move the wires aside as a unit. This will not only ensures the correct spark plug wire is reinstalled onto the correct cylinder, the guide clamps will also ensure correct routing of the wires. Because the spark plug wires conduct a high energy electrical current, the insulation of the wires must be kept clean and not allowed to rub against any object that may damage the insulation.

When removing the spark plugs, remove them one at a time in a logical order, noting which cylinder from which they were removed. A careful inspection of the spark plugs is one method of evaluating the engine's operating conditions. Spark plugs showing signs of a carbon build up or deposits around the center electrode, may be indications of an impending electrical or mechanical failure.

See Figure 3

Click image to see an enlarged view

Fig. Fig. 3: Label each spark plug wire before disengaging and/or disconnecting them one at a time

CRV and 4-Cylinder Odyssey Models

  1. Disconnect the negative battery cable, note the radio security code and, if the vehicle has been run recently, allow the engine to thoroughly cool.
  2.  
  3. Carefully remove the spark plug connectors from the spark plug by turning slightly while pulling. Do not use excessive force. If the connector seems to be stuck, turn the connector back and forth about a 1 / 4/ of a turn in each direction until the connector can be removed without excessive force.
  4.  
  5. Leaving the spark plug wires attached to the guide clamps, remove the clamps from the mounting brackets and place the spark plug wires safely as a unit.
  6.  

Remove the spark plugs when the engine is cold, if possible, to prevent damage to the threads. If removal of the plugs is difficult, apply a few drops of penetrating oil to the area around the base of the plug, and allowing it a few minutes to work.

See Figures 4, 5 and 6

Click image to see an enlarged view

Fig. Fig. 4: Rotate the plug wire cap 1/2 a turn and carefully pull upward. Using a suitable trim panel removal tool works well



Click image to see an enlarged view

Fig. Fig. 5: Inspect the plug wire boots and seals and make sure they are in good condition



Click image to see an enlarged view

Fig. Fig. 6: Be certain that the socket is squarely seated over the spark plug; otherwise, damage to the ceramic insulator could occur, making removal extremely difficult

  1. Using a spark plug socket equipped with a rubber insert to properly hold the plug, turn the spark plug counterclockwise to loosen and remove the spark plug from the threaded hole in the cylinder head.
  2.  

See Figure 7

Click image to see an enlarged view

Fig. Fig. 7: Depending on the tightness of the socket fit and the engine, carefully pull the spark plug out of the bore


WARNING
Avoid using a flexible extension on the spark plug socket. A flexible extension may allow a shear force to be applied to the plug. A shear force could break the plug off in the cylinder head, leading to costly repairs.

  1. Inspect the spark plug boot, connectors, and wires for tears, damage, or deterioration. Make sure the plug wires and connectors are clean, and free of debris, such as engine oil. If a damaged boot, wire, or connector is found, the spark plug wire assembly must be replaced.
  2.  
  3. Using a wire feeler gauge, check and adjust the spark plug gap. When using a gauge, the proper size should pass between the electrodes with a slight drag. The next larger size should not be able to pass, while the next smaller size should pass freely.
  4.  
  5. Adjust the spark plug gap to 0.039-0.043 inches (1.0-1.1mm).
  6.  

To install:
  1. Apply a light coating of an anti-seize compound to the spark plug threads.
  2.  
  3. Carefully thread the plug into the threaded spark plug hole by hand. If resistance is felt before the plug is almost completely threaded, back the plug out and begin threading again. In small, hard to reach areas, a small piece of rubber hose pressed onto the spark plug can be used as a threading tool. The rubber hose will hold the plug and while twisting the end of the hose, the hose will be flexible enough to twist before allowing the plug to crossthread.
  4.  


WARNING
Do not use any excessive force when beginning to install the plugs. Always carefully thread the plug by hand or by using a rubber hose to prevent the possibility of crossthreading and damaging the cylinder head threads.

  1. Carefully tighten the spark plug to 13 ft. lbs. (18 Nm).
  2.  
  3. Apply a small amount of silicone dielectric compound to the end of the spark plug lead or inside the spark plug boot to prevent sticking, then install the boot to the spark plug and push until it clicks into place. The click may be felt or heard, then gently pull back on the boot to assure proper contact.
  4.  
  5. Connect the negative battery cable and enter the radio security code.
  6.  

V6 Odyssey Models

Beginning with model year 1999 the Odyssey models came equipped with a 3.5L V6 engine that uses a coil over plug ignition system. Each of the spark plugs has its own ignition coil which mounts directly above the spark plug and eliminates the need for a distributor, distributor cap, rotor and spark plug wires. Because the ignition coils are placed above the spark plugs, the coils must be removed before the spark plugs can be accessed.

  1. Disconnect the negative battery cable, note the radio security code and, if the vehicle has been run recently, allow the engine to thoroughly cool.
  2.  
  3. Remove the trim covers located above the cylinder head covers.
  4.  
  5. Label the electrical terminals for each ignition coil, and detach the electrical connector from each ignition coil.
  6.  
  7. Remove the fasteners securing each ignition coil to the cylinder head cover, then remove the coils.
  8.  
  9. Using a spark plug socket equipped with a rubber insert to properly hold the plug, turn the spark plug counterclockwise to loosen and remove the spark plug from the threaded hole in the cylinder head.
  10.  


WARNING
Avoid using a flexible extension on the spark plug socket. A flexible extension may allow a shear force to be applied to the plug. A shear force could break the plug off in the cylinder head, leading to costly repairs.

  1. Inspect each ignition coil for damage, or deterioration. Make sure the coils are clean, and free of debris, such as engine oil. If a damaged coil is found, it should be replaced.
  2.  


WARNING
The original equipment spark plugs installed in the 3.5L V-6 engine are platinum tip spark plugs, and the plug gap must not be adjusted.

  1. Using a wire feeler gauge, check, but do not adjust the spark plug gap. When using a gauge, the proper size should pass between the electrodes with a slight drag. The next larger size should not be able to pass, while the next smaller size should pass freely.
  2.  
  3. The spark plug gap should be 0.039-0.043 inches (1.0-1.1mm). If the spark plug gap exceeds 0.051inches (1.3mm) replace the spark plug.
  4.  

To install:
  1. Apply a light coating of an anti-seize compound to the spark plug threads.
  2.  
  3. Carefully thread the plug into the threaded spark plug hole by hand. If resistance is felt before the plug is almost completely threaded, back the plug out and begin threading again. In tight, hard to reach areas, a small piece of rubber hose pressed onto the spark plug can be used as a threading tool. The rubber hose will hold the plug and while twisting the end of the hose, and the hose will be flexible enough to twist before allowing the plug to crossthread.
  4.  


WARNING
Do not use any excessive force when beginning to install the plugs. Always carefully thread the plug by hand or by using a rubber hose to prevent the possibility of crossthreading and damaging the cylinder head threads.

  1. Carefully tighten the spark plug to 13 ft. lbs. (18 Nm).
  2.  
  3. Install the ignition coils, then attach the electrical connector to each ignition coil.
  4.  
  5. Install the trim covers onto the cylinder head covers.
  6.  
  7. Connect the negative battery cable and enter the radio security code.
  8.  

INSPECTION & GAPPING



Check the plugs for deposits and wear. Look carefully at the center electrode protrudes through the center of the porcelain. If the center electrode is eroded or rounded, replace the spark plugs. If the plugs are not going to be replaced, clean the plugs thoroughly. Remember that any kind of deposit will decrease the efficiency of the plug. Plugs can be cleaned on a spark plug-cleaning machine, which are sometimes found in service stations. These machines do a good job of cleaning the spark plug, although they tend to remove the protective anti-corrosive coating on the spark plug threads. They also cause the surface of porcelain around the center electrode to become slightly porous, allowing deposits to bond more easily to the porcelain. If a plug cleaner is used to clean the plugs, be sure the plug is thoroughly cleaned. The abrasive material used in the spark plug cleaners is very hard, and if allowed to enter the engine's combustion chamber, could cause internal damage. An acceptable job of cleaning the spark plug can be accomplished by using a stiff wire brush. Once the plugs are cleaned, the spark plug gap must be checked and reset to specification.


WARNING
The original equipment spark plugs installed in the Odyssey 3.5L V-6 engine are platinum tip spark plugs, and the plug gap must not be adjusted.

Check spark plug gap before installation. Using a suitable spark plug gap gauge, check the spark plug gap. Make sure the L-shaped electrode connected to the body of the spark plug is parallel to the center electrode. If necessary, adjust the L-shaped electrode to attain the correct gap and proper alignment. Make sure to use the specified size wire gauge, which must pass between the electrodes with a slight drag and the next larger size should not be able to pass, while the next smaller size should pass freely. When adjusting a spark plug gap, always set the gap to the minimum specification to allow for electrode wear. Refer to the following information pertaining to spark plug gap.

On CRV and 4-cylinder Odyssey models, adjust the spark plug gap to 0.039-0.043 inches (1.0-1.1mm). On Odysseys with the V6 engine, check, but do not adjust the spark plug gap. The spark plug gap should be 0.039-0.043 inches (1.0-1.1mm). If the spark plug gap exceeds 0.051inches (1.3mm), replace the spark plug.

NEVER adjust the gap on a used platinum type spark plug.

Always check the gap on new plugs as they are not always set correctly at the factory. Do not use a flat feeler gauge when measuring the gap because the reading may be inaccurate. A round-wire type gapping tool is the best tool for checking the plug gap. The correct gauge should pass through the electrode gap with a slight drag. If in doubt, try one size smaller and one larger. The smaller gauge should go through easily, while the larger one shouldn't go through at all. Wire gapping tools usually have a bending tool attached. Use this to adjust the side electrode until the proper clearance is obtained. Never attempt to bend the center electrode. Be careful not to bend the side electrode too far or too often as it may weaken and break off inside the engine, requiring removal of the cylinder head to retrieve it.

See Figures 8 through 12

Click image to see an enlarged view

Fig. Fig. 8: Inspect the spark plug to determine engine running conditions



Click image to see an enlarged view

Fig. Fig. 9: A variety of tools and gauges are needed for spark plug service



Click image to see an enlarged view

Fig. Fig. 10: Checking the spark plug gap with a feeler gauge



Click image to see an enlarged view

Fig. Fig. 11: Adjusting the spark plug gap



Click image to see an enlarged view

Fig. Fig. 12: If the standard plug is in good condition, the electrode may be filed flat-WARNING: do not file platinum plugs

 
label.common.footer.alt.autozoneLogo