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Compression Test 3.3L

  1. Make sure the oil in the crankcase is of the correct viscosity and at the correct level and that the battery is correctly charged. Operate the vehicle until the engine is at normal operating temperature.
  2. Turn the ignition switch to the OFF position, then remove all the spark plugs. Refer to Spark Plugs .
    GFD510360Courtesy of FORD MOTOR COMPANY
  3. Loosen the clamp and position the air cleaner outlet pipe aside.
    GFD510361Courtesy of FORD MOTOR COMPANY
    1. Detach the degas bottle hose and position aside.
    2. Disconnect the quick release coupling and position aside the crankcase ventilation tube. REFER to: Quick Release Coupling .
    3. Disconnect the quick release coupling and position aside the atmospheric tube. REFER to: Quick Release Coupling .
    4. Detach the clip and position aside the vacuum tube.
    GFD510362Courtesy of FORD MOTOR COMPANY
  5. Loosen the clamp and remove the air cleaner outlet pipe.
    GFD510363Courtesy of FORD MOTOR COMPANY
  6. Manually set the throttle plates to the wide-open position.
  7. Install a compression gauge in the No. 1 cylinder.
  8. Install an auxiliary starter switch in the starting circuit. With the ignition switch in the OFF position, and using the auxiliary starter switch, crank the engine a minimum of 5 compression strokes and record the highest reading. Note the approximate number of compression strokes necessary to obtain the highest reading.
  9. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.
  10. Install all the spark plugs. Refer to Spark Plugs .
    GFD510362Courtesy of FORD MOTOR COMPANY
  11. Install the air cleaner outlet pipe and tighten the clamp.
    GFD510361Courtesy of FORD MOTOR COMPANY
    1. Connect the degas bottle hose.
    2. Install the crankcase ventilation tube. REFER to: Quick Release Coupling .
    3. Connect the atmospheric tube. REFER to: Quick Release Coupling .
    4. Attach the vacuum tube.
    GFD510360Courtesy of FORD MOTOR COMPANY
  13. Install the air cleaner outlet pipe and tighten the clamp.
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