Log In
Search suggestions

    My Vehicles

    1969 Chevrolet Biscayne 4.1L 1BL OHV 6cyl

    My Store

    9920 PARAMOUNT BLV
    (562) 776-3393

    CLOSED Open at 7:30 AM

    GET A $25 GIFT CARD FOR EVERY $100 SPENT ON ONLINE SHIP-TO-HOME ORDERS.

    Use Code: GIFTME

    See Details

    Lincoln Aviator, Ford Explorer, Exp Sport, Exp Sport-Trac, Mercury Mountaineer 2000-2005

    Spark Plugs

    Print

    Inspection



    Check the plugs for deposits and wear.

    Check spark plug gap before installation. The ground electrode (the L-shaped one connected to the body of the plug) must be parallel to the center electrode and the specified size wire gauge (please refer to the Tune-Up Specifications chart for details) must pass between the electrodes with a slight drag.


    NOTE
    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 on a used plug, because the reading may be inaccurate. A round-wire type gapping tool is the best way to check the gap. The correct gauge should pass through the electrode gap with a slight drag. If you're 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 that to adjust the side electrode until the proper distance is obtained. Absolutely never attempt to bend the center electrode. Also, be careful not to bend the side electrode too far or too often as it may weaken and break off within the engine, requiring removal of the cylinder head to retrieve it.

    Click image to see an enlarged view

    Fig. Checking the spark plug gap with a feeler gauge



    Click image to see an enlarged view

    Fig. Adjusting the spark plug gap



    Click image to see an enlarged view

    Fig. Inspect the spark plug to determine engine running conditions

    Inspection & Gapping



    Check the plugs for deposits and wear.

    Check spark plug gap before installation. The ground electrode (the L-shaped one connected to the body of the plug) must be parallel to the center electrode and the specified size wire gauge (please refer to the Tune-Up Specifications chart for details) must pass between the electrodes with a slight drag.


    NOTE
    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 on a used plug, because the reading may be inaccurate. A round-wire type gapping tool is the best way to check the gap. The correct gauge should pass through the electrode gap with a slight drag. If you're 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 that to adjust the side electrode until the proper distance is obtained. Absolutely never attempt to bend the center electrode. Also, be careful not to bend the side electrode too far or too often as it may weaken and break off within the engine, requiring removal of the cylinder head to retrieve it.

    Click image to see an enlarged view

    Fig. Checking the spark plug gap with a feeler gauge



    Click image to see an enlarged view

    Fig. Adjusting the spark plug gap



    Click image to see an enlarged view

    Fig. Inspect the spark plug to determine engine running conditions

    Removal & Installation





    Click image to see an enlarged view

    Fig. Always twist and pull on the spark plug boot, never on the wire


    NOTE
    Ford recommends replacing standard spark plugs every 100,000 miles.

    When you're removing spark plugs, work on one at a time. Don't start by removing the plug wires all at once, because, unless you number them, they may become mixed up. Take a minute before you begin and number the wires with tape. Also, an anti-seize compound should be used before installing the plugs into the cylinder head.

    1. Disconnect the negative battery cable, and if the vehicle has been run recently, allow the engine to thoroughly cool.
    2.  
    3. Carefully twist the spark plug wire boot to loosen it, then pull upward and remove the boot from the plug. Be sure to pull on the boot and not on the wire, otherwise the connector located inside the boot may become separated.

      Click image to see an enlarged view

      Fig. Remove the spark plug wire from the plug by twisting the boot and pulling outwards. Never pull on the wire

    4.  
    5. Using compressed air, blow any water or debris from the spark plug well to assure that no harmful contaminants are allowed to enter the combustion chamber when the spark plug is removed.
      NOTE
      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 penetrating oil or spray to the area around the base of the plug, and allow it a few minutes to work.

    6.  
    7. Using a spark plug socket that is equipped with a rubber insert to properly hold the plug, turn the spark plug counterclockwise to loosen and remove the spark plug from the bore.
      WARNING
      Be sure not to use a flexible extension on the socket. Use of 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 and frustrating repairs.



      Click image to see an enlarged view

      Fig. Using the proper size spark plug socket, loosen the plug by rotating it counterclockwise



      Click image to see an enlarged view

      Fig. Once the plug is loose, you should be able to remove it by hand. Compare the plug against the examples given

    8.  

    To install:

    1. Inspect the spark plug boot for tears or damage. If a damaged boot is found, the spark plug wire must be replaced.
      NOTE
      Coat the spark plug threads with an anti-seize compound before installing it into the cylinder head.

    2.  
    3. Carefully thread the plug into the bore 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, an old spark plug wire and boot could be used as a threading tool. The boot will hold the plug while you twist the end of the wire and the wire is supple enough to twist before it would allow the plug to cross-thread.
      WARNING
      Do not use the spark plug socket to thread the plugs. Always carefully thread the plug by hand or using an old plug wire to prevent the possibility of cross-threading and damaging the cylinder head bore.

    4.  
    5. Carefully tighten the spark plug.
      1. 2000-01, 4.0L and 5.0L engines tighten to 15 ft. lbs (20 Nm)
      2.  
      3. 2003-05 DOHC 4.6L engines tighten to 15 ft. lbs. (20 Nm)
      4.  
      5. 2002-04 SOHC 4.0L engine tighten to 15 ft. lbs. (20 Nm)
      6.  
      7. 2002-04 SOHC 4.6L engine tighten to 12 ft. lbs. (16 Nm)
      8.  
      9. 2005 SOHC 4.0L and 4.6L engines tighten to 13 ft. lbs. (17 Nm)
      10.  

    6.  
    7. 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.
    8.  


    NOTE
    Ford recommends replacing standard spark plugs every 100,000 miles.

    When you're removing spark plugs, work on one at a time. Don't start by removing the plug wires all at once, because, unless you number them, they may become mixed up. Take a minute before you begin and number the wires with tape. Also, an anti-seize compound should be used before installing the plugs into the cylinder head.

    1. Disconnect the negative battery cable, and if the vehicle has been run recently, allow the engine to thoroughly cool.
    2.  
    3. Carefully twist the spark plug wire boot to loosen it, then pull upward and remove the boot from the plug. Be sure to pull on the boot and not on the wire, otherwise the connector located inside the boot may become separated.

      Click image to see an enlarged view

      Fig. Always twist and pull on the spark plug boot, never on the wire



      Click image to see an enlarged view

      Fig. Remove the spark plug wire from the plug by twisting the boot and pulling outwards. Never pull on the wire

    4.  
    5. Using compressed air, blow any water or debris from the spark plug well to assure that no harmful contaminants are allowed to enter the combustion chamber when the spark plug is removed.
      NOTE
      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 penetrating oil or spray to the area around the base of the plug, and allow it a few minutes to work.

    6.  
    7. Using a spark plug socket that is equipped with a rubber insert to properly hold the plug, turn the spark plug counterclockwise to loosen and remove the spark plug from the bore.
      WARNING
      Be sure not to use a flexible extension on the socket. Use of 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 and frustrating repairs.



      Click image to see an enlarged view

      Fig. Using the proper size spark plug socket, loosen the plug by rotating it counterclockwise



      Click image to see an enlarged view

      Fig. Once the plug is loose, you should be able to remove it by hand. Compare the plug against the examples given

    8.  

    To install:

    1. Inspect the spark plug boot for tears or damage. If a damaged boot is found, the spark plug wire must be replaced.
      NOTE
      Coat the spark plug threads with an anti-seize compound before installing it into the cylinder head.

    2.  
    3. Carefully thread the plug into the bore 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, an old spark plug wire and boot could be used as a threading tool. The boot will hold the plug while you twist the end of the wire and the wire is supple enough to twist before it would allow the plug to cross-thread.
      WARNING
      Do not use the spark plug socket to thread the plugs. Always carefully thread the plug by hand or using an old plug wire to prevent the possibility of cross-threading and damaging the cylinder head bore.

    4.  
    5. Carefully tighten the spark plug to 15 ft. lbs. (20 Nm).
    6.  
    7. 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.
    8.  

     
    AutoZone Logo