Chevrolet Trax: Spark plug inspection
Spark Plug Usage
- Ensure that the correct spark plug is installed. An incorrect spark plug
causes driveability conditions.
Refer to the Electronic Parts Catalog.
- Ensure that the spark plug has the correct heat range. An
incorrect heat range causes the following
conditions:
- Spark plug fouling-Colder plug
- Pre-ignition causing spark plug and/or engine damage-Hotter plug
Spark Plug Inspection
Fig. 88: Cross Sectional View Of Spark Plug
- Inspect the terminal post (1) for damage.
- Inspect for a bent or broken terminal post (1).
- Test for a loose terminal post (1) by twisting and pulling the post. The
terminal post (1) should
NOT move.
Fig. 89: Identifying Points For Inspecting Spark Plug For Flashover Or Carbon
Tracking Soot
- Inspect the insulator (2) for flashover or carbon tracking, soot. This
is caused by the electrical charge
traveling across the insulator (2) between the terminal post (1) and ground.
Inspect for the following
conditions:
- Inspect the spark plug boot for damage.
- Inspect the spark plug recess area of the cylinder head for moisture,
such as oil, coolant, or water. A
spark plug boot that is saturated causes arcing to ground.
Fig. 90: Inspecting Spark Plug Insulator
- Inspect the insulator (2) for cracks. All or part of the electrical
charge may arc through the crack instead
of the electrodes (3, 4).
Fig. 91: Cutaway/Description View Of Spark Plug
- Inspect for evidence of improper arcing.
- Measure the gap between the center electrode (4) and the side electrode
(3) terminals. An
excessively wide electrode gap can prevent correct spark plug 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.
Spark Plug 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 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 intensity. Most powdery deposits will not effect
spark intensity unless
they form into a glazing over the electrode.
READ NEXT:
Fig. 92: Spark Plugs
Spark Plug Replacement
CAMSHAFT POSITION ACTUATOR SOLENOID VALVE REPLACEMENT
Removal Procedure
Fig. 93: ECM Wiring Harness
Disconnect the intake camshaft position actuator
Fig. 101: Crankshaft Position Sensor
Crankshaft Position Sensor Replacement
CAMSHAFT POSITION SENSOR REPLACEMENT
Fig. 102: Camshaft Position Sensor
Camshaft Position Sensor Replacement
KNOCK
Removal Procedure
Remove the front bumper fascia. Refer to Front Bumper Fascia Replacement
(Trax) , Front Bumper
Fascia Replacement (Encore)
Fig. 109: Charge Air Cooler Inlet Air Hose Clamp
SEE MORE:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptor
DT
Warning
Do not store heavy or sharp
objects in storage compartments.
In a crash, these objects may
cause the cover to open and
could result in injury.
If equipped, pull the handle to open.
Slide the latch to open.
Press the button to open the
storage above the glovebox.