P0304 on Chrysler
Cylinder 4 Misfire Detected
P0304 on Chrysler vehicles indicates cylinder 4 misfire detected. Au7o has documented this code across 6 Chrysler models — most commonly on 300, Aspen, Pacifica. This code means the engine computer detected a misfire in cylinder number 4 — that cylinder isn't igniting its air-fuel mixture fully or at all. The system detects this by monitoring small changes in crankshaft rotation speed as each cylinder fires. You may feel a rough idle, shaking, hesitation or reduced power, and a persistent misfire can dump unburned fuel into the exhaust and overheat or damage the catalytic converter. Since it's pinpointed to one cylinder, the problem typically lies in that cylinder's spark, fuel, or compression. Typical repair costs on Chrysler range from $100 to $8,000, depending on the specific model and root cause.
Common Causes of P0304
- •Worn or fouled spark plug in cylinder 4
- •Failed or weak ignition coil on cylinder 4
- •Faulty spark plug wire or boot (where applicable)
- •Clogged, stuck or leaking fuel injector for cylinder 4
- •Vacuum or intake air leak near that cylinder
- •Low compression (worn rings, burnt/leaking valve, head gasket)
- •Damaged wiring or connector at the coil or injector
P0304 on Chrysler by Model
Chrysler 300(2 issues)
- HEMI 5.7L MDS Lifter and Camshaft Failure2011-2023
The 5.7L HEMI V8 suffers from MDS lifter design defect where needle bearings are undersized. Lifters can be starved of oil during idle, causing seizure and catastrophic camshaft wear leading to engine failure.
- Pentastar Cylinder Head Failure2011-2016
Left cylinder head on early Pentastar engines suffers valve seat failure in cylinder #2. Valve seats overheat and drop out of aluminum head causing catastrophic misfires and potential engine damage. Design flaw later addressed.
Chrysler Aspen(1 issue)
- 5.7L HEMI MDS Lifter Tick and Camshaft Failure2007-2009
Same HEMI 5.7L lifter/camshaft failure issue affecting all MDS-equipped engines. The MDS lifters have undersized needle bearings that fail from oil starvation at idle, causing catastrophic camshaft wear. Persistent ticking that worsens over time indicates lifter failure in progress.
Chrysler Pacifica(1 issue)
- 3.6L Pentastar Engine Stalling and Head Gasket Failure2017-2024
The 3.6L Pentastar V6 in Pacifica models suffers from engine stalling due to loose ground connections (recall NHTSA 19V348), crankshaft position sensor sync issues, and premature head gasket failures typically around 75,000-85,000 miles. Cooling system failures can lead to coolant entering the combustion chamber, requiring complete engine replacement.
Chrysler PT Cruiser(3 issues)
- Chronic Overheating - Multiple Causes2001-2010
PT Cruisers are extremely prone to overheating from multiple causes: radiator fan relay failure, fan motor failure, thermostat sticking closed, radiator clogging, and water pump failure. The high-speed fan relay is the most frequent single failure point. Overheating leads to head gasket failure. This is one of the most universally reported problems across all model years.
- Head Gasket Failure (Especially Turbo Models)2001-2010
Head gasket failure is common, especially on turbo models. The aluminum cylinder head is susceptible to pitting from acidic coolant which compromises the gasket seal. Turbo models experience higher cylinder pressures that accelerate failure. Overheating from cooling system issues frequently triggers head gasket failure.
- Turbocharger Failure (GT/Turbo Models)2003-2010
The turbocharger on GT and turbo models fails from oil starvation, wastegate actuator failure, and bearing wear. Failures reported as early as 60,000-78,000 miles. Turbo failure is often followed by head gasket failure within months due to changes in combustion pressure dynamics.
Chrysler Sebring(1 issue)
- 3.5L V6 Head Gasket Failure and Overheating2001-2010
The 3.5L V6 engine has common issues including leaky head gaskets, coolant leaks, and overheating. The water pump uses a molded plastic impeller that erodes from rust and sediment in the coolant, reducing cooling efficiency. These engines run hot and are prone to oil sludging, especially if oil is not changed every 3,000 miles.
Chrysler Town & Country(1 issue)
- Cooling System Failures (3.3L/3.8L V6)2001-2010
The 3.3L and 3.8L V6 engines suffer from water pump failures, thermostat failures, and radiator fan relay failures. The water pump weep hole is a common leak point. Overheating can cause head gasket failure. The cooling fan relay is a frequent failure point causing overheating at idle.
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View P0304 across all makes →Frequently Asked Questions
What does P0304 mean on Chrysler?▼
P0304 stands for "Cylinder 4 Misfire Detected." This code means the engine computer detected a misfire in cylinder number 4 — that cylinder isn't igniting its air-fuel mixture fully or at all. The system detects this by monitoring small changes in crankshaft rotation speed as each cylinder fires. You may feel a rough idle, shaking, hesitation or reduced power, and a persistent misfire can dump unburned fuel into the exhaust and overheat or damage the catalytic converter. Since it's pinpointed to one cylinder, the problem typically lies in that cylinder's spark, fuel, or compression. On Chrysler specifically, this code is documented across 6 models.
What causes P0304 on Chrysler vehicles?▼
Common causes on Chrysler: Worn or fouled spark plug in cylinder 4, Failed or weak ignition coil on cylinder 4, Faulty spark plug wire or boot (where applicable), Clogged, stuck or leaking fuel injector for cylinder 4, Vacuum or intake air leak near that cylinder. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0304 on a Chrysler?▼
Repair costs on Chrysler range from $100 to $8,000, depending on the specific model and root cause.
Which Chrysler models have P0304 documented?▼
Au7o has documented P0304 on 6 Chrysler models: 300, Aspen, Pacifica, PT Cruiser, Sebring, Town & Country.