Envoy, Rainer, Trailblazer 2006-2007

Ignition Coil Pack

Print

Removal & Installation



4.2L Engine
  1. Remove the air cleaner outlet resonator.
  2.  
  3. Disconnect the ignition coil connectors (1) from the ignition coils.

    Click image to see an enlarged view

    Fig. Detach the connectors (1) and remove the bolts (2) from the ignition coils

  4.  
  5. Remove the retaining bolts (2) from the ignition coils.
  6.  
  7. Remove the ignition coils (1) from the engine.
  8.  

To install:


NOTE
Make sure that the ignition coil seals are properly seated to the valve cover.

  1. Install the ignition coil.
  2.  
  3. Install the ignition coil retaining bolts and tighten to 89 inch lbs. (10 Nm).
  4.  
  5. Replace the ignition coil connectors.
  6.  
  7. Install the air cleaner outlet resonator.
  8.  

5.3L & 6.0L Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the spark plug wire from the ignition coil.
  4.  
  5. Disconnect the ignition coil electrical connector.
  6.  
  7. Remove the ignition coil bolts.
  8.  
  9. Remove the ignition coil.
  10.  

To install:

  1. Install the ignition coil.
  2.  
  3. Install the ignition coil bolts and tighten to 71 inch lbs. (8 Nm).
  4.  
  5. Connect the ignition coil electrical connector.
  6.  
  7. Connect the spark plug wire to the ignition coil.
  8.  
  9. Connect the negative battery cable.
  10.  

Testing



  1. Disconnect the coil leads.
  2.  
  3. Set the ohmmeter in the low range, and recalibrate if necessary.
  4.  
  5. Connect the ohmmeter leads across the ignition coil primary terminals, and compare the primary resistance reading to specifications (typically less than 2 ohms).
  6.  
  7. Then connect the ohmmeter leads across the coil secondary terminals and compare the secondary resistance reading to specifications (typically 6,000-30,000 ohms).
  8.  
  9. If readings are outside the specified range, the coil is defective and needs to be replaced.
  10.  
  11. Measure secondary resistance of the coil is difficult because of the coils location, try removing the wires from the spark plugs or where the coil meets the spark plug and measure secondary resistance through the plug wires rather than at the secondary terminals on the coils. The general rule of thumb is to add in a maximum of 8,000 ohms of resistance per foot for the plug wires.
  12.  
  13. On the 4.2L engine, pay close attention to the tube that wraps around the spark plug. Cracks can allow voltage to jump to ground causing a misfire. The spark plug terminal should also fit tightly.
  14.  
  15. If resistance is out of specifications, the coil is bad and needs to be replaced.
    NOTE
    If a coil-on-plug tests bad and is replaced, future problems can often be avoided by cleaning the coil-on-plug connector and wiring harness terminals. Corrosion at either place can cause intermittent operation and loss of continuity, which may contribute to component failure. Applying dielectric grease to these connections can help prevent corrosion and assure a good electrical connection.

  16.  

 
label.common.footer.alt.autozoneLogo