P0305 on Hyundai
Cylinder 5 Misfire Detected
P0305 on Hyundai vehicles indicates cylinder 5 misfire detected. Au7o has documented this code across 3 Hyundai models — most commonly on Elantra, Sonata, Tucson. This code means the engine control module detected a misfire on cylinder number 5, meaning that cylinder is not burning its air-fuel mixture properly on some combustion cycles. The computer senses misfires by watching for tiny fluctuations in crankshaft speed each time a cylinder fails to fire correctly. A misfire wastes fuel, can make the engine run rough or shake, and dumps unburned fuel into the exhaust, which can overheat and damage the catalytic converter. It generally points to a problem with spark, fuel delivery, or compression specifically affecting cylinder 5. Typical repair costs on Hyundai range from $4,000 to $8,000, depending on the specific model and root cause.
Common Causes of P0305
- •Worn or fouled spark plug on cylinder 5
- •Failed ignition coil or coil pack for cylinder 5
- •Faulty or clogged fuel injector on cylinder 5
- •Vacuum or intake air leak affecting that cylinder
- •Bad spark plug wire or boot (on applicable engines)
- •Low compression from worn rings, valves, or head gasket
- •Carbon buildup or sticking valve on cylinder 5
- •Lean or rich fuel condition affecting the cylinder
P0305 on Hyundai by Model
Hyundai Elantra(1 issue)
- Nu Engine Bearing Failure and Seizure2011-2016
The 1.8L Nu engine in 2011-2016 Elantras is prone to premature failure due to manufacturing defects including piston ring issues, connecting rod bearing failure, and oil passage problems. Metal debris from failed components can circulate through the engine causing catastrophic damage. A class action settlement covered these vehicles with extended warranty up to 140,000 miles.
Hyundai Sonata(1 issue)
- Theta II Engine Seizure/Failure2011-2019
The Theta II engine can seize due to metal debris blocking oil flow to connecting rod bearings. Hyundai issued recalls and extended warranties. Affected engines may need replacement.
Hyundai Tucson(1 issue)
- Theta II Engine Seizure Due to Connecting Rod Bearing Failure2011-2019
The Theta II GDI engine in 2011-2019 Tucson models is susceptible to connecting rod bearing failure caused by manufacturing debris restricting oil flow. This can lead to catastrophic engine seizure, often without warning. Hyundai issued multiple recalls (19V-601, 20V-150) and extended the engine warranty to 15 years/unlimited miles for original owners.
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View P0305 across all makes →Frequently Asked Questions
What does P0305 mean on Hyundai?▼
P0305 stands for "Cylinder 5 Misfire Detected." This code means the engine control module detected a misfire on cylinder number 5, meaning that cylinder is not burning its air-fuel mixture properly on some combustion cycles. The computer senses misfires by watching for tiny fluctuations in crankshaft speed each time a cylinder fails to fire correctly. A misfire wastes fuel, can make the engine run rough or shake, and dumps unburned fuel into the exhaust, which can overheat and damage the catalytic converter. It generally points to a problem with spark, fuel delivery, or compression specifically affecting cylinder 5. On Hyundai specifically, this code is documented across 3 models.
What causes P0305 on Hyundai vehicles?▼
Common causes on Hyundai: Worn or fouled spark plug on cylinder 5, Failed ignition coil or coil pack for cylinder 5, Faulty or clogged fuel injector on cylinder 5, Vacuum or intake air leak affecting that cylinder, Bad spark plug wire or boot (on applicable engines). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0305 on a Hyundai?▼
Repair costs on Hyundai range from $4,000 to $8,000, depending on the specific model and root cause.
Which Hyundai models have P0305 documented?▼
Au7o has documented P0305 on 3 Hyundai models: Elantra, Sonata, Tucson.