Spark Plug: Testing and Inspection

1. Inspect the electrodes and ceramic insulator for:

Burned or worn electrodes may be caused by:
- Advanced ignition timing
- Loose spark plug
- Plug heat range too hot
- Insufficient cooling

Fouled plug may be caused by:
- Retarded ignition timing
- Oil in combustion chamber
- Incorrect spark plug gap
- Plug heat range too cold
- Excessive idling/low speed running
- Clogged air cleaner element
- Deteriorated ignition coil or ignition wires

Electrode Gap:

2. Do not adjust the gap of platinum tip plugs; replace the spark plug if the gap is out of specification or if the center electrode is rounded.




3. Replace the plug at the specified interval, or if the center electrode is rounded as shown below:

NOTE: Use only the spark plugs listed below.

Spark Plugs
PFR5L - 11 (NGK)
PK16PR - L11 (DENSO)

4. Apply a small quantity of anti-seize compound to the plug threads, and screw the plugs into the cylinder head finger-tight. Then torque them to 18 N.m (1.8 kgf.m, 13 lbf.ft).