Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2012 GMC Terrain AWD L4-2.4LFACTORY OEM SERVICE PROCEDURE
Spark Plug: Service and Repair
Spark Plug Replacement
Removal Procedure
Caution:
This engine has aluminum cylinder heads. Do not remove the spark plugs from a hot engine, allow it to cool first. Removing the spark plugs from a hot engine may cause spark plug thread damage or cylinder head damage.
1. Remove the ignition coil(s). Refer to Ignition Coil Replacement Service and Repair.
Note:
Make sure that any water and/or debris is blown out of the spark plug holes prior to removing the spark plugs.
2. Remove the spark plugs using a 5/8 inch spark plug socket.
Installation Procedure
Caution:
Refer to Fastener Caution Fastener Caution.
Caution:
Do not coat spark plug threads with anti-seize compound. If anti-seize compound is used and spark plugs are over-torqued, damage to the cylinder head threads may result.
1. Install the spark plugs.
The spark plug gap is 1.0 mm (0.040 in).
Tighten the plugs to 20 Nm (15 lb ft).
2. Install the ignition coil(s). Refer to Ignition Coil Replacement Service and Repair.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.