P0306 on 2011-2013 Dodge Grand Caravan: Cylinder 6 Misfire and Head Fixes

What's Unique About the 2011-2013 Dodge GRAND CARAVAN

The 2011-2013 Dodge Grand Caravan is equipped with the first generation of the 3.6L Pentastar V6. Early versions of this engine are notorious for a specific defect affecting the left-side cylinder head, which causes premature valve guide and seat wear. This leads to compression loss and misfires, specifically on cylinders 2, 4, and 6. The issue was so widespread that Chrysler issued Technical Service Bulletin 09-002-14 and a 10-year/150,000-mile warranty extension (X56) to address it. The redesigned cylinder head, introduced in mid-2012, uses hardened valve guides and seats to resolve the problem. Therefore, a P0306 code on this specific vehicle has a much higher than normal probability of being a major engine-related fault rather than a simple ignition or fuel issue.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Rough or shaky idle
• Engine hesitation or stumbling during acceleration
• Noticeable loss of power
• Flashing or solid Check Engine Light
• Audible ticking or tapping sound from the engine's left side, often called the 'Pentastar Tick'
• Coolant sloshing sound from behind the dashboard, indicating combustion gases in the cooling system

Most Likely Causes

1. Failed Left Cylinder Head 🔴 High Probability A known manufacturing defect in early 3.6L Pentastar engines (built on or before July 25, 2012) caused premature wear of the valve guides and seats in the left cylinder head. This was acknowledged by Chrysler through TSB #09-002-14 and warranty extension X56.
   How to confirm: After ruling out spark plugs and ignition coils, a cylinder leak-down test is the definitive diagnostic step. TSB 09-002-14 Rev. B specifically instructs technicians to test cylinders 2, 4, and 6. If any of these cylinders exhibit leakage of 25% or greater, the cylinder head is confirmed to be the cause. Hydrocarbons in the coolant are also a strong indicator.
   Typical fix: Replacement of the left cylinder head assembly with the updated part (part number RL141353AC or 68141353AC), which features more robust, hardened valve guides and seats.
   Est. part cost: $750-$1200 for a remanufactured or new OEM head assembly. Shop replacement cost is much higher, often in the $3,400-$3,800 range.
2. Worn Camshaft Lobes / Rocker Arms 🔴 High Probability Beyond the cylinder head issue, the 3.6L Pentastar is also known for premature failure of the roller rocker arms due to needle bearings wearing out and falling into the engine. This causes the arm to become loose, creating a ticking noise and eventually damaging the camshaft lobe, leading to a misfire.
   How to confirm: This can be difficult to diagnose as symptoms (ticking, misfire) mimic the cylinder head failure. If a leak-down test comes back good (under 25% leakage), the next step is to remove the valve cover for the left bank and physically inspect the rocker arms and camshaft lobes for wear, scoring, or excessive play. A collapsed lifter may also be found.
   Typical fix: Replace all rocker arms and lifters on the affected bank. 🎬 Watch: Step-by-step guide to replacing rocker arms and camshafts If the camshaft lobes are damaged, the camshafts must also be replaced. This is a labor-intensive job.
   Est. part cost: $100-$500 for a set of rocker arms and lifters.
3. Worn Spark Plug 🟡 Medium Probability
   How to confirm: Visually inspect the spark plug from cylinder 6. Look for a worn electrode, fouling, cracks in the porcelain, or rust-colored staining which could indicate a coolant leak. The easiest test is to swap the cylinder 6 spark plug with one from another cylinder (e.g., cylinder 1). If the misfire code changes to P0301, the spark plug is the culprit.
   Typical fix: Replace the spark plug. It is recommended to replace all six spark plugs at the same time.
   Est. part cost: $5-$20 per plug
4. Failed Ignition Coil 🟡 Medium Probability The OEM ignition coils on the 3.6L Pentastar are prone to thermal degradation and internal resistance breakdown from heat soak cycles.
   How to confirm: Swap the ignition coil from cylinder 6 with the coil from another cylinder (e.g., cylinder 1). Clear the codes and run the engine. If the misfire code moves to P0301, the ignition coil is faulty.
   Typical fix: Replace the failed ignition coil.
   Est. part cost: $30-$70 for an aftermarket coil, $100-$170 for an OEM Mopar coil.
5. Faulty Fuel Injector ⚪ Low Probability
   How to confirm: This is more complex to diagnose. One can listen for the injector's clicking sound with a mechanic's stethoscope. A more advanced method involves swapping injectors between cylinders to see if the misfire follows, but this is more labor-intensive as it requires removing the fuel rail. A multimeter can be used to check the injector's resistance; a good injector should read around 12 ohms.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $50-$150

Rare But Worth Checking

• Blown Head Gasket: While the cylinder head itself is the more common failure point, a simple head gasket failure between a coolant passage and cylinder 6 can also cause a misfire. Symptoms include coolant consumption, white smoke from the exhaust, and a spark plug that appears rusty or steam-cleaned.
• Vacuum Leak: A leak in the intake manifold gasket near the cylinder 6 runner could lean out the air/fuel mixture enough to cause a misfire. This is worth checking, especially if the intake manifold was recently removed for other service.
• Casting Sand in Cooling System: Some early Pentastar engines had residual casting sand left in the block, which could form a sludge in the cooling system. This can lead to overheating and hot spots in the cylinder head, potentially contributing to head failure.

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner. 🎬 Watch: Diagnosing P0300 and P0306 misfire codes on a Caravan Check if P0306 is present alone or with other codes like P0300, P0302, or P0304.
2. Swap the ignition coil from cylinder 6 to cylinder 1. Clear the codes and drive the vehicle. If the code changes to P0301, the ignition coil is bad.
3. If the code remains P0306, swap the spark plug from cylinder 6 to cylinder 3. Clear the codes and drive. If the code changes to P0303, the spark plug is bad.
4. If the misfire does not move, the issue is specific to the cylinder. Listen for a loud ticking from the left side of the engine.
5. Perform a cylinder leak-down test on cylinders 2, 4, and 6. Per TSB #09-002-14 Rev. B, if any cylinder shows leakage of 25% or greater, the left cylinder head must be replaced.
6. If the leak-down test results are good (under 25% leakage), remove the left valve cover. Carefully inspect all rocker arms for excessive play and check for any that have dislodged needle bearings. Inspect the camshaft lobes for scoring or unusual wear patterns.
7. If all mechanical checks pass, inspect the wiring and connector for the cylinder 6 fuel injector and consider testing fuel pressure.

Parts You'll Likely Need

• Left Cylinder Head Assembly (OEM #RL141353AC (or 68141353AC)) — This is the most common major cause for P0306 on this specific vehicle due to a known manufacturing defect. The replacement head has been updated to fix the issue.
  Trusted brands: Mopar
  OEM price range: $850-$1200
  Aftermarket price range: $600-$900
• Rocker Arm & Lifter Kit (OEM #5184296AH) — A common failure point on the 3.6L Pentastar that causes ticking and misfires, often mistaken for the cylinder head issue.
  Trusted brands: Mopar, Sealed Power, DNJ
  OEM price range: $250-$400
  Aftermarket price range: $100-$250
• Ignition Coil (OEM #5149168AH) — A common failure item that can cause a single-cylinder misfire. It's a key part of the diagnostic process.
  Trusted brands: Mopar, NGK, Denso
  OEM price range: $100-$170
  Aftermarket price range: $30-$70
• Spark Plug (OEM #SP149125AE) — A basic maintenance item that can cause a misfire if worn or fouled. It's the first and cheapest part to check.
  Trusted brands: Champion, NGK
  OEM price range: $10-$25
  Aftermarket price range: $5-$15

Related Codes That Often Appear With This One

• P0300 — If the cylinder head issue is severe or multiple rocker arms fail, it can cause misfires on multiple cylinders in the same bank, leading to a P0300 (Random/Multiple Cylinder Misfire) code.
• P0302 — This indicates a misfire on cylinder 2. Seeing P0302, P0304, and P0306 together is a very strong indicator of the known left cylinder head failure, as all three are on the same bank and listed in the TSB.
• P0304 — This indicates a misfire on cylinder 4. Its presence alongside P0306 reinforces the diagnosis of a bank-wide problem, likely the cylinder head.

Technical Service Bulletins (TSBs) & Recalls

• 09-002-14 Rev. B: MIL Illumination: P0300, P0302, P0304 or P0306 (X56 Warranty Extension)
• 09-002-14a: MIL Illumination: P0300, P0302, P0304 or P0306 (X56 Warranty Extension)
• 09-002-14: MIL Illumination: P0300, P0302, P0304 or P0306 (X56 Warranty Extension)

Platform-Specific Known Issues

• NHTSA TSB #09-002-14 Rev. B: This Technical Service Bulletin explicitly addresses P0300, P0302, P0304, and P0306 on these vehicles. It instructs technicians to perform a cylinder leak-down test on the left bank (cylinders 2, 4, 6) and, if leakage is 25% or greater, to replace the left cylinder head under warranty extension X56.
• Warranty Extension X56: Chrysler extended the warranty on the left cylinder head to 10 years or 150,000 miles from the vehicle's in-service date for affected 2011-2013 models due to this known defect. This warranty has likely expired for most vehicles by now.
• NHTSA ODI #11465911: An owner of a 2013 model reported, 'Engine misfire, check engine light P0306, P0304, P0302 due to left side head needing replacement.' This directly corroborates the TSB.
• NHTSA ODI #11415608: An owner of a 2013 model reported multiple codes including P0302, P0304, and P0306, describing the engine as bucking and skipping, which is a classic symptom of this issue.

Mechanic-Grade Diagnostic Values

• Fuel Pressure — expected: 400 kPa +/- 14 kPa (58 psi +/- 2 psi). Failure: Pressure significantly below or above this range indicates a fuel pump or regulator issue.
• Fuel Injector Resistance — expected: 12 to 16 Ohms. Failure: A reading outside this range, especially a very high (open) or low (short) reading, indicates a failed injector.
• Ignition Coil Primary Resistance — expected: 0.558 to 0.682 Ohms at 25°C (77°F). Failure: Resistance outside of this specified range indicates a faulty coil.
• Ignition Coil Secondary Resistance — expected: 15.70 kOhms. Failure: A reading significantly higher or lower than the specification points to a bad coil.

Scan Tool Commands That Help

• wiTECH (Chrysler/Dodge/Jeep OEM tool): OBD II Monitors -> 'Which cylinder is misfiring' — This function is particularly useful when dealing with a random misfire code (P0300) to view live misfire counts for each cylinder and isolate the problematic one(s) without having to swap components.
• wiTECH (or other advanced scan tool): Fuel Injector Actuation Test — After confirming spark and compression are good, this command allows you to individually fire a fuel injector while a noid light is connected. If the noid light doesn't blink, it confirms an issue with the injector's control circuit or the PCM.

Wiring & Ground Locations

• Cylinder 6 Ignition Coil Connector — On top of the valve cover for the rear bank of cylinders (left side), connected to the ignition coil for the cylinder closest to the driver's side.. The connector and its wiring are the final link between the PCM and the ignition coil. A damaged connector, corroded pins, or a broken wire in the harness can prevent the coil from firing, causing a P0306 misfire even with a good coil.
• Cylinder 6 Fuel Injector Connector — On the fuel rail for the rear bank of cylinders (left side), connected to the fuel injector for the cylinder closest to the driver's side. Access requires removing the upper intake manifold.. A fault in this connector or its wiring can prevent the fuel injector from opening, starving cylinder 6 of fuel and causing a misfire. The PCM can shut down the injector control circuit if a misfire is detected, so testing requires a scan tool to actuate the injector.

Real Owner Repair Stories

• DodgeForum.com user 'Mr.Bones' (2013 Dodge Grand Caravan, 175,000 miles) — Shuttering and shaking on acceleration, check engine light came on with code P0306.
  ❌ Tried (didn't work) Initial diagnosis pointed towards an O2 sensor, but the light went off and came back as P0306.
  ✅ What actually fixed it The user swapped the ignition coil from cylinder 6 to cylinder 1. The code changed to P0301, confirming a bad ignition coil. Replacing the faulty coil and all spark plugs resolved the issue.
• Reddit user 'redgus78' (2014 Chrysler Town & Country (same 3.6L Pentastar engine)) — P0306 code and rough idle.
  ❌ Tried (didn't work) Swapping coils, Swapping injectors, Replacing spark plugs, Compression check (was good), Leak down test (was good), Visual inspection of valve cover (no visible wear)
  ✅ What actually fixed it The problem was ultimately a worn exhaust rocker arm and a damaged cam lobe on cylinder 6, which was not immediately visible upon initial inspection.

OEM Part Supersession History

• 05184445AI (and others ending in AA, AB) → RL141353AC or 68141353AC — The original cylinder heads had improperly hardened valve guides and seats, leading to premature wear and compression loss. The updated parts use hardened materials to resolve the defect.
• 5184296AD, 5184296AE, 5184296AF, 5184296AG → 5184296AH — The rocker arm design was updated to improve the durability of the needle bearings in the roller, which were a common failure point causing the 'Pentastar tick' and subsequent camshaft damage.
  Heads up: Using older revision rocker arms on a newer engine or vice-versa may lead to valvetrain noise or failure due to slight profile differences. It is critical to use the latest 'AH' revision for repairs.
• 05184085AC → 0280158233 — General part revision and supplier changes for the fuel injector.

Model Year Variations Within This Range

• 2011-mid 2012: These model years were equipped with the original left cylinder head design that is prone to premature valve guide and seat wear, making P0306 (along with P0302 and P0304) highly indicative of this specific failure.
• Late 2012-2013: Chrysler began phasing in the redesigned cylinder head with hardened valve guides in mid-2012 (specifically after July 25, 2012). While these later models are less susceptible to the head defect, failures of rocker arms and lifters remain a common cause for P0306 across all years.