AutoCodes – Chevrolet – P0308 2017 Chevrolet Silverado

P0308 2017 Chevrolet Silverado Code - Cylinder 8 Misfire Detected

Quick Answer

A misfiring cylinder causes slight variations in the rotational speed of the crankshaft. Common causes include Faulty spark plug 8, Clogged or faulty fuel injector 8, Faulty ignition coil 8. 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: P0308 2017 Chevrolet Silverado indicates Cylinder 8 Misfire Detected.
Common causes: Common causes include Faulty spark plug 8, Clogged or faulty fuel injector 8, Faulty ignition coil 8.
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 Popularity 669

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Aug 09, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0308 2017 Chevrolet Silverado Description

A misfiring cylinder causes slight variations in the rotational speed of the crankshaft. The Engine Control Module (ECM) can detect these variations by closely monitoring the crankshaft position sensor signal. The signals of the camshaft position sensors are used to determine which cylinder is misfiring. If the ECM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, the Diagnostic Trouble Code (DTC) will be set. Under certain driving conditions, a misfire rate can be high enough to cause the catalytic converter to overheat, damaging the converter. The Malfunction Indicator Lamp (MIL) flashes when the converter is overheating, damaging conditions are present, and the DTC is set. The DTC will be set when the ECM detects a crankshaft rotation speed variation indicating a single-cylinder misfire rate sufficient to cause emissions levels to exceed mandated standards.

OBDII Code P0308 2017 Chevrolet Silverado - Cylinder 8 Misfire Detected - AutoCodes.com — P0308 2017 Chevrolet Silverado Code - Cylinder 8 Misfire Detected

What does this mean?

What are the Possible Causes of the DTC P0308 2017 Chevrolet Silverado?

Faulty spark plug 8
Clogged or faulty fuel injector 8
Faulty ignition coil 8
Fuel injector 8 harness is open or shorted
Fuel injector 8 circuit poor electrical connection
Ignition coil 8 harness is open or shorted
Ignition coil 8 circuit poor electrical connection
Insufficient cylinder 8 compression
Incorrect fuel pressure
Intake air leak

How to Fix the DTC P0308 2017 Chevrolet Silverado?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0308 code means that cylinder 8 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 8. If the problem persists more tests need to be done to diagnose the problem, see "Possible Causes".

There is a Factory Service Bulletins for All 2000-2020 Chevrolet Models:
2000-2020 Chevrolet Factory Service Bulletin OBDII Code P0308
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.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0308 2017 Chevrolet Silverado code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0308 2017 Chevrolet Silverado code?

Need more information on how to fix the P0308 2017 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0308 2017 Chevrolet Silverado Code

What does the OBDII code P0308 mean?

The P0308 code indicates a misfire has been detected in cylinder 8 of your 2017 Chevrolet Silverado.

What are the common symptoms of a P0308 code?

Symptoms may include a rough idle, reduced engine performance, poor fuel economy, and the check engine light turning on.

What can cause a P0308 code in a 2017 Chevrolet Silverado?

Common causes include faulty spark plugs, a bad ignition coil, clogged fuel injectors, low compression, or issues with the cylinder 8 wiring or connectors.

Can driving with a P0308 code damage my engine?

Yes, prolonged driving with a cylinder misfire can cause damage to the catalytic converter or other engine components.

How do I diagnose a P0308 code?

Start by checking the spark plug, ignition coil, and wiring for cylinder 8. You may also need to inspect the fuel injector and perform a compression test.

Can bad fuel cause a P0308 code?

Yes, contaminated or low-quality fuel can contribute to a cylinder misfire, including P0308.

How much does it cost to fix a P0308 code?

Repair costs vary depending on the cause but could range from $100 for a spark plug replacement to $500+ for fuel injector repairs or other complex fixes.

Can a dirty air filter cause a P0308 code?

While unlikely, a severely clogged air filter can affect engine performance and potentially contribute to misfires.

Do I need a professional mechanic to fix a P0308 code?

If you're comfortable with basic repairs, you can replace spark plugs or ignition coils yourself. For complex issues like low compression, professional help is recommended.

Can the P0308 code be cleared without fixing the issue?

You can clear the code with an OBDII scanner, but it will likely return unless the underlying problem is resolved.