P0306 on Chrysler: How to Diagnose & Fix
Cylinder 6 Misfire Detected
4 Chrysler models · 5 documented issues · 5 critical · $1,500-$6,000 repair
P0306 on Chrysler by model: symptoms, diagnosis and fix
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.
Common Symptoms
- Persistent ticking or tapping noise from engine
- Ticking worsens between 80,000-100,000 miles
- Check engine light with misfire codes
- Rough idle or loss of power
- Metal shavings in oil
How to Fix
Replace all lifters, camshaft, and rocker arms as assembly. Use only OEM or high-quality lifters. Some owners disable MDS system. Use only SAE 5W-20 oil and maintain strict 3,000-5,000 mile oil change intervals.
Sources for this issue (1)
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.
Common Symptoms
- Persistent misfire on cylinder #2
- Check engine light with P0302 code
- Rough idle and loss of power
- Ticking or rattling from left side of engine
How to Fix
Complete cylinder head replacement required (left/driver's side). Cannot be repaired - must replace entire head with updated design. Some cases require both heads preventatively. Full coolant flush and thermostat replacement recommended.
Sources for this issue (2)
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.
Common Symptoms
- Persistent ticking noise at idle
- Ticking worsens over time
- Check engine light with misfire codes
- Metal shavings in oil
How to Fix
Replace all lifters, camshaft, and rocker arms. Consider Hellcat non-MDS lifter upgrade (8784AD) for MDS delete. Use Melling high-volume oil pump M10452HV (2009+). Maintain strict 3,000-5,000 mile oil change intervals with synthetic oil.
Sources for this issue (1)
Early-build 3.6L Pentastar V6 engines suffer accelerated valve guide and valve seat wear on the LEFT (driver's side) cylinder head, producing a persistent misfire on one of the left-bank cylinders and an illuminated MIL. It is frequently accompanied by the 'Pentastar tick.' The defect is specific to the left head - the right head is not affected - and to early Pentastar production, which is why FCA issued a warranty extension rather than a recall. Owners on the Chrysler minivan forums report repeat failures where a replacement head was installed with the same early casting. Some owners with matching symptoms and matching engine build dates were told their VIN falls outside the extension, which produced a class-action claim covering 3.6L vehicles excluded from the extension.
Common Symptoms
- Rough idle and misfire on a left-bank cylinder
- Check engine light with a single-cylinder misfire code
- Ticking noise from the driver's side of the engine
- Reduced power / engine shake under load
- Misfire returns shortly after a plug-and-coil replacement
How to Fix
FCA extended the warranty on the left cylinder head to 10 years/150,000 miles from in-service date on 2011-2013 vehicles with the 3.6L. The repair is replacement of the left cylinder head with the updated casting (and the rocker arms/lifters if the tick damaged them). Call a Chrysler dealer with the VIN to confirm coverage before paying out of pocket - the extension is VIN-gated by engine build date, not by model year alone. Out of warranty this is a full left-head R&R.
Sources for this issue (3)
The 3.6L Pentastar V6 has a documented valvetrain defect involving the rocker arms and their roller lift pins and the associated hydraulic lifters. The roller on a rocker arm can prematurely wear, loosen and drop, shifting the rocker out of alignment so it scrapes the camshaft and generates metal debris that contaminates the oil and circulates through the engine. Symptoms include a persistent ticking/tapping noise, misfires, hesitation/bucking, rough running and loss of power, and in severe cases catastrophic engine failure requiring a full engine replacement. A proposed class action against FCA US alleges the automaker knew of the valve-train defect in 2014-2020 model year vehicles (which includes the 2020 launch year of the modern Voyager); ECM software governing lifter timing was also implicated.
Common Symptoms
- Ticking or tapping noise from the engine (often at idle/cold start)
- Cylinder misfire
- Hesitation, bucking or surging
- Loss of power
- Check engine light flashing/on
- Rough idle
How to Fix
Diagnose the failing cylinder(s) via misfire codes and cylinder-specific inspection. Accepted repair is replacement of the affected rocker arm(s) and lifter(s); if debris has circulated or multiple cylinders are affected, a cylinder head or full engine replacement may be required. Apply any applicable PCM/ECM software update. Frequent oil changes with correct-spec oil and not deferring the ticking noise limit collateral damage.
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 Chrysler?
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 Chrysler it is documented across 4 models: 300, Aspen, Town & Country, Voyager.
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 Chrysler?
Published repair estimates on Chrysler range from $1,500 to $6,000 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.