Toyota Highlander 6 2001-06

Spark Plugs

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Inspection



2.4L Engine

WARNING
Never use a wire brush to clean the spark plug. Do not adjust the electrode gap of a used spark plug.

  1. Check the electrode, as follows:
    1. Measure the insulation resistance using a megaohmmeter. The proper resistance is 10 MW or higher If the resistance is less than specifications, go to the next step
      NOTE
      If a megaohmmeter is not available, perform the following inspection instead:



      Click image to see an enlarged view

      Fig. Measuring the resistance of the spark plug insulator



      Quickly accelerate the engine to 4,000 rpm 5 times.
       
      Remove the spark plug.
       
      Visually check the spark plug.
       
      If the electrode is dry, the spark plug is functioning.
       
      If the electrode is damp, proceed to the next steps.
       
      Install the spark plug.
       
      Check the spark plug for any damage on its thread and insulator.
       
      If there is damage, replace the spark plug.
       

    2.  

  2.  
  3. Check the spark plug electrode gap. Maximum electrode gap for used spark plug: 1.3 mm (0.051 in.). If the gap is greater than the maximum, replace the spark plug. Correct electrode gap for new spark plug: 1.0 to 1.1 mm (0.039 to 0.043 in.)
    NOTE
    If adjusting the gap of a new spark plug, bend only the base of the ground electrode. Do not touch the tip. Never attempt to adjust the gap on a used plug.


    NOTE
    Only use the spark plug cleaner when the electrode is free of oil. If the electrode has traces of oil, use gasoline to clean off the oil before using the spark plug cleaner.



    Clean the spark plugs. If the electrode has traces of wet carbon, clean the electrode with a spark plug cleaner and then dry it.
     

  4.  

3.0L And 3.3L Engines

NOTE
Try not to clean the iridium and platinum tip. However, when the cleaning is necessary, use of spark plug cleaner is recommended. The duration of cleaning should be less than 20 seconds.

  1. Check the spark plug for thread damage and insulator damage. If abnormal, replace the spark plug.
    NOTE
    The recommended type of spark plug for the Highlander is:



    DENSO MADE SK20R11
     
    NGK MADE IFR6A11
     

  2.  
  3. Check the electrode gap.
    1. Electrode gap: 1.0-1.1mm (0.039-0.043 in.)
    2.  
    3. Maximum electrode gap: 1.2mm(0.047 in.)
      WARNING
      This engine is fitted with iridium-tipped spark plugs. Never attempt to adjust the electrode gap. Do not scratch the iridium and platinum tip between electrode gap.

    4.  

  4.  

Highlander Hybrid

WARNING
Do not use a wire brush for cleaning. Do not attempt to adjust the electrode gap of a used spark plug.

  1. Check the electrode, as follows:
    1. Using a megaohmmeter, measure the insulation resistance.
    2.  
    3. Correct insulation resistance is 10 m- or higher.
    4.  
    5. If the resistance is less then the specified value, proceed to the next step.
      NOTE
      If a megaohmmeter is not available, perform the following simple inspection instead.



      Click image to see an enlarged view

      Fig. Use a megohmmeter to measure the resistance of the spark plug insulation

    6.  

  2.  
  3. Alternative inspection method:
    1. Quickly accelerate the engine to 4,000 rpm 5 times.
    2.  
    3. Remove the spark plug.
    4.  
    5. Visually check the spark plug.
    6.  
    7. If the spark plug is dry, reinstall the spark plug. If the spark plug is wet, go to the next step.
    8.  

  4.  
  5. Check the spark plug for any damage to its threads and insulator. If there is any damage, replace the spark plug. The recommended spark plug for these models is:
    1. Denso: SK20R11
    2.  
    3. NGK: IFR6A11
    4.  

  6.  
  7. Check the spark plug electrode gap. Maximum electrode gap for used spark plug is 1.3 mm (0.051 in.). If the gap is greater than the maximum, replace the spark plug. The correct electrode gap for new spark plug is 1.0 to 1.1 mm (0.039 to 0.043 in.).

    Click image to see an enlarged view

    Fig. Check, but do not adjust, the electrode gap

  8.  
  9. Clean the spark plugs. If the electrode has traces of wet carbon, clean the electrode with a spark plug cleaner and then dry it.
    NOTE
    If there are traces of oil, remove them with gasoline before using the spark plug cleaner.

  10.  

Removal & Installation



2.4L Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the No. 1 engine cover.
  4.  
  5. Remove the ignition coils. Refer to the procedure in this section for more details.
  6.  
  7. Using a 16 mm (0.63 in.) plug wrench, remove the spark plugs.
  8.  
  9. Inspect the condition of the spark plugs, as outlined in this section.
  10.  

To install:

  1. Using a 16 mm (0.63 in.) plug wrench, install the spark plugs and tighten to 14 ft. lbs. (19 Nm).
  2.  
  3. Install the ignition coils and tighten to 80 inch lbs. (9 Nm).
  4.  
  5. Install the No. 1 engine cover and tighten to 80 inch lbs. (9 Nm).
  6.  
  7. Connect the negative battery cable.
  8.  

3.3L Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the V-bank cover.
  4.  
  5. Remove the intake air surge tank.
  6.  
  7. Remove the ignition coils. For more details, refer to the procedure in this section.
  8.  
  9. Using a 16 mm (0.63 in.) plug wrench, remove the spark plugs.
  10.  

To install:

  1. Using a 16 mm (0.63 in.) plug wrench, install the spark plugs and tighten to 18.5 ft. lbs. (25 Nm).
  2.  
  3. Install the ignition coil and tighten the retainers to 71 inch lbs. (8 Nm).
  4.  
  5. Install the intake air surge tank.
  6.  
  7. Install the V-bank cover.
  8.  
  9. Connect the negative battery cable.
  10.  

Hybrid
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the ignition coils, as outlined in this section.
  4.  
  5. Use a spark plug socket and wrench and remove the spark plugs.
  6.  
  7. Inspect the condition of the spark plugs, as outlined in this section.
  8.  

To install:

  1. Install the spark plugs and tighten to 18 ft. lbs. (25 Nm).
  2.  
  3. Install the ignition coils, as outlined in this section.
  4.  
  5. Connect the negative battery cable.
  6.  
  7. If necessary, perform the initialization procedure, as outlined in the Chassis Electrical System.
  8.  

 
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