Sierra 1500 2WD V8-5.3L VIN B HO (2006)
operation.
-
Inspect for the correct spark plug torque. Insufficient torque can prevent correct spark plug operation. An over torqued spark plug, causes the
insulator (2) to crack.
-
Inspect for signs of tracking that occurred near the insulator tip instead of the center electrode (4).
-
Inspect for a broken or worn side electrode (3).
-
Inspect for a broken, worn, or loose center electrode (4) by shaking the spark plug.
-
A rattling sound indicates internal damage.
-
A loose center electrode (4) reduces the spark intensity.
-
Inspect for bridged electrodes (3, 4). Deposits on the electrodes (3, 4) reduce or eliminates the gap.
-
Inspect for worn or missing platinum pads on the electrodes (3, 4), if equipped.
-
Inspect for excessive fouling.
-
Inspect the spark plug recess area of the cylinder head for debris. Dirty or damaged threads can cause the spark plug not to seat correctly during
installation.
VISUAL INSPECTION
-
Normal operation - Brown to grayish-tan with small amounts of white powdery deposits are normal combustion by-products from fuels with
additives.
-
Carbon fouled - Dry, fluffy black carbon, or soot caused by the following conditions:
-
Rich fuel mixtures
-
Leaking fuel injectors
-
Excessive fuel pressure
-
Restricted air filter element
-
Incorrect combustion
-
Reduced ignition system voltage output
-
Weak ignition coils
-
Worn ignition wires
-
Incorrect spark plug gap
-
Excessive idling or slow speeds under light loads can keep spark plug temperatures so low that normal combustion deposits may not burn off.
-
Deposit fouling - Oil, coolant, or additives that include substances such as silicone, very white coating, reduces the spark plug intensity. Most
powdery deposits will not affect spark plug intensity unless they form into a glazing over the electrode.