Town & Country Van AWD V6-230 3.8L VIN L SMFI (1998)
Shiny yellow glaze coating on the insulator.
POSSIBLE CAUSE
ACTION
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Metal By-products Of Combustion
- Avoid sudden acceleration with wide open throttle after long periods of low speed driving.
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Spark Plug Inspection
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Remove the spark plugs and examine them for burned electrodes. Also check for fouled, cracked or broken porcelain insulators. Keep plugs
arranged in the order in which they were removed from the engine. An isolated plug displaying an abnormal condition indicates that a problem
exists in the corresponding cylinder. Replace spark plugs at the intervals recommended in the Maintenance Schedules.
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Spark plugs that have low mileage may be cleaned and reused if not otherwise defective. Refer to the Spark Plug Condition of this section. After
cleaning, file the center electrode flat with a small point file or jewelers file. Adjust the gap between the electrodes to the specified dimension. The
spark plug gap is 0.89 mm (0.035 in).
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Always tighten spark plugs to the specified torque. Over tightening can cause distortion resulting in a change in the spark plug gap.
Spark Plug Resistance Test
Resistance should be at least 6,000 to 20,000 ohms when checked with at least a 1000 volt tester.
Wet Oily Deposits
Symptoms: Electrodes coated with excessive wet fuel or oil.
Possible Causes:
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In older engines, wet fouling can be caused by worn rings or excessive cylinder wear.
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In new or recently overhauled engines, fouling may occur before normal oil control is achieved. Break-in fouled spark plugs can be usually
be cleaned and installed.
White or Gray - Burned or Blistered Insulator
Spark Plug Overheating
Symptoms: White or gray center electrode insulator that also appears blistered. The increase in electrode gap will be considerably in excess of
0.001 in per 1000 miles of operation.
Possible Causes:
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Plug(s) with wrong heat range.
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Over advanced ignition timing.
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Detonation
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Cooling system malfunction
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Check for lean air-fuel mixture
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Check the torque value of the plugs to ensure good plug-engine seat contact
