P0307 2018 GMC Sierra Code - Cylinder 7 Misfire Detected
Quick Answer
When a diagnostic trouble code P0307 is triggered in a 2018 GMC Sierra, it indicates that a misfire has been detected in cylinder 7 of the engine. Common causes include Worn or fouled spark plugs in cylinder 7, Faulty ignition coil specific to cylinder 7, Clogged fuel injector for cylinder 7. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0307 2018 GMC Sierra indicates Cylinder 7 Misfire Detected.
- Common causes
- Common causes include Worn or fouled spark plugs in cylinder 7, Faulty ignition coil specific to cylinder 7, Clogged fuel injector for cylinder 7.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P0307 2018 GMC Sierra Description
When a diagnostic trouble code P0307 is triggered in a 2018 GMC Sierra, it indicates that a misfire has been detected in cylinder 7 of the engine. A misfire occurs when the fuel-air mixture in the cylinder fails to ignite at the proper time, causing a disruption in the combustion process. This can lead to a variety of issues such as rough idling, decreased fuel efficiency, loss of power, and increased emissions.
Common Causes of P0307 2018 GMC Sierra
- Worn or fouled spark plugs in cylinder 7.
- Faulty ignition coil specific to cylinder 7.
- Clogged fuel injector for cylinder 7.
- Low compression in cylinder 7 due to a damaged valve or piston ring.
- Vacuum leak affecting cylinder 7.
Symptoms of P0307 2018 GMC Sierra
- Rough idling or vibrations while the vehicle is running.
- Loss of power or acceleration when driving.
- Increased fuel consumption.
- Engine misfires or hesitation during acceleration.
- Illumination of the check engine light on the dashboard.
How to Fix P0307 2018 GMC Sierra
- Begin by diagnosing the specific cause of the misfire in cylinder 7 using a scan tool to identify the underlying issue.
- Inspect and replace the spark plugs in cylinder 7 if they are worn or fouled.
- Test and replace the ignition coil for cylinder 7 if it is found to be faulty.
- Clean or replace the fuel injector for cylinder 7 to ensure proper fuel delivery.
- Check the compression in cylinder 7 and address any mechanical issues such as a damaged valve or piston ring if necessary.
Cost to Fix P0307 2018 GMC Sierra
The cost of repairing a cylinder 7 misfire in a 2018 GMC Sierra can vary depending on the specific cause of the issue. On average, the parts required for the repair, such as spark plugs, ignition coils, or fuel injectors, could range from $50 to $200. Labor costs at an auto repair shop could add an additional $100 to $300, depending on the shop's hourly rate and the complexity of the repair. Overall, the total cost of addressing a P0307 code in a GMC Sierra could range from $150 to $500. It's recommended to obtain quotes from local auto repair shops to get a more accurate estimate based on your location and vehicle specifics.
Tech Notes for P0307 2018 GMC Sierra
There is a Factory Service Bulletins for All 2000-2020 Chevrolet Models:
2000-2020 Chevrolet Factory Service Bulletin OBDII Code P0307
This Factory Service Bulletin explains how this condition may be caused by significant carbon build-up on the intake and/or exhaust valves due to fuel contamination or incomplete burning of the fuel.
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