The 2012 Chevy Cruze uses coil-on-plug ignition, so each spark plug sits directly beneath a separate ignition coil on the cylinder head. Depending on the engine option, access is typically gained by removing the ignition coils and then the spark plugs themselves. This guide covers both the common 1.8L four-cylinder and the 1.4L turbo variants, helping you locate, inspect, and replace the plugs correctly.
Engine Variants In The 2012 Cruze
The 2012 Cruze lineup includes a 1.8L four-cylinder engine and a 1.4L turbocharged four-cylinder. Both engines use a coil-on-plug configuration and have four ignition coils and four spark plugs. In each case, the plugs are positioned in the cylinder head and are accessed by removing the coil packs first. Familiarize yourself with the layout before starting to avoid accidental misdiagnosis of ignition or fuel system issues.
Where To Look For Spark Plugs
On both the 1.8L and 1.4L turbo engines, the spark plugs sit under the ignition coils on top of the engine valve cover. The coils are mounted directly over each spark plug. To locate them:
- Open the hood and locate the valve cover with four/ four coil packs aligned along it.
- Identify the coil pack over each cylinder. Each coil connects to a spark plug beneath it.
- Follow the ignition coil leads to each plug well—these are the access points for removing the coils.
Visual cues are consistent: four ignition coils arranged in a square or linear pattern on the top of the engine, each paired with a spark plug beneath it. If the engine cover is present, you may need to remove it to clearly access the coils and plugs.
Accessing The Spark Plugs In The 1.8L Engine
Replacement steps for the 1.8L model are straightforward but require care to avoid damaging the coil connectors or wiring harness.
- Disconnect the negative battery cable to prevent accidental electrical shorts.
- Unplug the electrical connector from each ignition coil.
- Remove the coil bolts and lift the coils straight up to expose the spark plugs.
- Wipe the plug wells and then use a spark plug socket with a magnetic extension to loosen and remove the old plugs.
- Check the gap on new plugs to the recommended specification (typically around 0.040 inches, but verify with the manual).
- Install new plugs finger-tight, then snug with a torque wrench to the manufacturer’s specification.
- Reinstall coils, reconnect wiring, and reattach the battery terminal. Clear any codes if present.
Notes: Always inspect coil boots for wear and replace any damaged boots during the same service interval to prevent misfires. Use anti-seize on plugs only if recommended by Chevrolet, otherwise rely on proper torque.
Accessing The Spark Plugs In The 1.4L Turbo Engine
The 1.4L Turbo also uses coil-on-plug ignition, with four coils over four spark plugs. The process mirrors the 1.8L approach but with attention to turbo-specific components nearby.
- Disconnect the negative battery terminal.
- Unplug each ignition coil electrical connector and remove coil mounting bolts.
- Lift the coils to reveal the spark plugs. Do not pry on the coil housing.
- Use a spark plug socket with a magnetic extension to remove the old plugs.
- Check plug gap on new plugs (common spec is near 0.040 inches; confirm in the owner’s manual).
- Install new plugs with proper torque and reseat the ignition coils. Reconnect connectors and battery.
Tip: The 1.4L turbo’s tighter engine bay means you may need a small, low-profile ratchet and extensions to reach the rear plugs. Take your time to avoid damaging the coil boots.
Replacement Tips And Common Issues
Proper spark plug maintenance supports fuel economy, starting performance, and smooth idling. Consider these key tips:
- Use the correct heat range and gap setting specified by Chevrolet for your engine.
- Replace all four plugs at the same time to maintain even performance across cylinders.
- Inspect ignition coils for signs of wear, such as cracks or impedance changes, and replace if needed.
- Keep the coil boots clean and free of oil or corrosion to maintain a solid seal and reliable spark delivery.
- When diagnosing misfires, rule out vacuum leaks, fuel delivery issues, and sensor faults before replacing plugs.
Maintenance Schedule And Tools
Spark plug replacement intervals vary by engine and driving conditions. For the 2012 Cruze:
- Reference the owner’s manual for factory-recommended intervals, which are typically around 100,000 miles for certain spark plug types on modern engines, but verify for both 1.8L and 1.4L turbo versions.
- Common tools needed: spark plug socket with extension, ratchet, torque wrench, needle-nose pliers, and a magnetic pickup tool.
- Have a spare set of ignition coils or boots on hand in case a coil is damaged during plug replacement.
Important: Always ensure the engine is cool before starting work to prevent scalding and to avoid warping the metal components. After finishing, start the engine and listen for smooth operation; misfires or rough starts may indicate improper plug seating or coil connection.