P0306 on Genesis: How to Diagnose & Fix
Cylinder 6 Misfire Detected
1 Genesis model · 1 documented issue · $300-$1,500 repair
P0306 on Genesis by model: symptoms, diagnosis and fix
Some 3.3T owners report elevated engine-oil consumption — in one documented case roughly 2 quarts over a ~320-mile trip, accompanied by bluish exhaust smoke indicating oil burning. The consumed oil contributes to heavy intake-valve carbon (the 3.3T is direct-injected), sooty/wet spark plugs, and multi-cylinder misfire codes. Consumption is intermittent across the fleet (many cars use little to no oil), so owners should monitor levels between changes rather than assume the engine is unaffected.
Common Symptoms
- Oil level dropping noticeably between changes
- Bluish/grey exhaust smoke, especially on startup or under load
- Low-oil warning earlier than expected
- Fouled (sooty/wet) spark plugs and misfire codes
- Heavy intake-valve carbon found at service
How to Fix
Document consumption with a dealer oil-consumption test (measured top-offs over a set mileage) while the powertrain warranty is in force. Inspect the PCV system and turbo seals for oil ingestion, replace fouled spark plugs, and clean carboned intake valves (walnut blast) if buildup is found. Check the oil level frequently between changes and use the correct spec oil; severe consumption may require dealer powertrain repair under warranty.
Sources for this issue (1)
P0306 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0306 mean on a Genesis?
P0306 stands for "Cylinder 6 Misfire Detected." This code means the engine computer detected a misfire on cylinder 6 — that cylinder isn't burning its fuel-air mixture properly. The computer senses misfires by watching for tiny variations in crankshaft speed each time a cylinder should fire, and when cylinder 6 repeatedly fails to contribute, this code sets. You may feel a shake or stumble, especially at idle or under load, along with reduced power and possibly a flashing check-engine light, which signals a misfire severe enough to damage the catalytic converter. A misfire comes down to a problem with spark, fuel, or compression in that cylinder. On Genesis it is documented across 1 model: G70.
What are the most common causes of P0306?
The most common causes of P0306 are: Worn or fouled spark plug on cylinder 6, Failed ignition coil for cylinder 6, Clogged, leaking, or failed fuel injector, Vacuum or intake air leak affecting that cylinder, Low compression (worn rings, burnt valve, head gasket), Damaged plug wire or coil connector, Carbon buildup or worn valvetrain components. The specific cause varies by vehicle.
How much does it cost to fix P0306 on a Genesis?
Published repair estimates on Genesis range from $300 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0306 on a different make?
View P0306 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.