Cylinder 8 Contribution/Balance Fault
The P0284 code means the vehicle's onboard diagnostic system has detected: Cylinder 8 Contribution/Balance Fault. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $600 (parts and labor)
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What Are the Symptoms of P0284?
- Engine misfire on cylinder 8
- Rough idle and vibration
- Check Engine Light illuminated
- Uneven power delivery
- Engine shakes especially at idle
What Causes P0284? (Most Likely First)
- Faulty cylinder 8 fuel injector (incorrect fuel delivery) Very High
- Low compression in cylinder 8 High
- Leaking or clogged injector on cylinder 8 High
- Vacuum leak at cylinder 8 intake runner Moderate
- Worn camshaft lobe affecting cylinder 8 valves Low
Can I Still Drive with P0284?
Short distances only. P0284 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
Can I drive with code P0272?
You can drive short distances with light loads. Cylinder 8 is producing less power than normal, and the engine will run rough. Avoid towing until repaired.
Is P0272 always a serious problem?
Not always. It could be as simple as a clogged injector that needs cleaning. However, low compression or a worn camshaft lobe would indicate a more serious mechanical issue requiring significant repair.
Can fuel quality cause a contribution fault?
Contaminated or low-quality fuel can cause injector clogging and uneven fuel delivery, which may trigger contribution codes. Using quality fuel and periodic injector cleaning can help prevent this.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0284?
-
Perform a cylinder contribution test using a scan tool to compare each cylinder's output
-
Run a compression test -- cylinder 8 should be within 10% of the highest cylinder
-
Swap cylinder 8 injector with another cylinder to determine if the injector is the cause
-
Check for vacuum leaks at cylinder 8 intake port using a smoke machine
-
If compression is low, perform a leak-down test to identify the failure point
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
P0284 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
Which Vehicles Commonly Get P0284?
- 2010-2020 Ford Mustang GT (5.0L V8)
- 2012-2019 Chevrolet Corvette (6.2L V8)
- 2008-2018 Dodge Charger (5.7L HEMI)
- 2011-2020 GMC Sierra (5.3L V8)
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