NOTE: It is important to check the gap of all new and reconditioned spark plugs before installation. Pre-set gaps may have changed during handling. Use a round wire feeler gauge to be sure of an accurate check, particularly on used plugs. Installing plugs with the wrong gap can cause poor engine performance and may even damage the engine.

Gap the spark plugs to the specifications. Refer to Ignition System Specifications .

NOTE: Be sure plug threads smoothly into cylinder head and is fully seated. Use a thread chaser if necessary to clean threads in cylinder head. Cross-threading or failing to fully seat spark plug can cause overheating of plug, exhaust blow-by, or thread damage. Follow the recommended torque specifications carefully. Over or under-tightening can also cause severe damage to engine or spark plug.

Install the spark plugs to the engine.
Tighten:
- If installing the spark plugs to a new cylinder head tighten the plugs to 20 N.m (15 lb ft).
- If installing the spark plugs to an existing cylinder head tighten the plugs to 15 N.m (11 lb ft).
Install the spark plug wires to the spark plugs. Refer to Spark Plug Wire Replacement .
Release the J 41131 and return the engine to the original position.
Install the engine mount struts. Refer to Engine Mount Strut Replacement - Left and Engine Mount Strut Replacement - Right in Engine Mechanical - 3.4L.

Fig 1: Identifying Spark Plug & Wire

Courtesy of GENERAL MOTORS CORP.

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.

Safety Warning

Installation Procedure

Use the Manual With the Right Hardware

When to See a Mechanic

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