Expedition 4WD V8-4.6L SOHC VIN 6 (1997)
Spark Plug: Customer Interest
Spark Plug Wires - MIL ON/DTCs P0300 Through P0308 Set
Article No.
96-25-23
12/02/96
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RUNS ROUGH - MALFUNCTION INDICATOR LAMP (MIL) ON-DIAGNOSTIC TROUBLE CODES (DTCS) P0300 THROUGH P0308
STORED IN MEMORY - VEHICLES BUILT THROUGH 10/14/96 WITH 4.6L ENGINE
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LAMP - MALFUNCTION INDICATOR LAMP (MIL) ON - RUNS ROUGH - DIAGNOSTIC TROUBLE CODES (DTCS) P0300 THROUGH
P0308 STORED IN MEMORY - VEHICLES BUILT THROUGH 10/14/96 WITH 4.6L ENGINE
LIGHT TRUCK:
1997 ECONOLINE, EXPEDITION, F-150
ISSUE:
The Malfunction Indicator Lamp (MIL) may illuminate and Diagnostic Trouble Codes (DTCs) P0300 through P0308 may be stored in memory and/or
the engine may run rough. This may be caused by water intrusion into the spark plug well causing the spark to travel directly to ground instead of
through the spark plug, resulting in a misfire.
ACTION:
Inspect the spark plugs for signs of moisture and replace the spark plugs and spark plug wires. Apply dielectric compound on all of the spark plug wire
boots. The new spark plug wires and the dielectric compound should reduce the possibility of misfire if water intrusion into the spark plug well occurs.
Refer to the following Service Procedure for details.
SERVICE PROCEDURE
1.
Inspect and remove any water that may be sitting in the spark plug wells by blowing out the water using compressed air.
2.
Inspect the spark plugs for signs of "tracking." If "tracking" is present, there may be a fine, broken "pencil" line on the blue rings only and/or a
thick smudgy series of continuous lines depending on how long the vehicle was operated while misfiring. These lines may feel like a crack if the
fingernail is rubbed across the lines. Refer to Figure 1.
3.
If "tracking" is found, replace all eight (8) of the spark plugs and torque the new Spark Plugs (AWSF-32-PP) to 16-20 N.m (12-15 lb-ft).
4.
Replace all eight (8) of the Spark Plug Wires with new wires (F6PZ-12259-HC). Be sure to apply Silicone Caliper Grease and Dielectric
Compound (D7AZ-19A331-A) on the inside of all spark plug wire boots.
