P0305 on 2012-2014 Dodge Avenger: Cylinder 5 Misfire Causes and Fixes

What's Unique About the 2012-2014 Dodge AVENGER

This code can only appear on Avengers equipped with the 3.6L Pentastar V6 engine, as the 4-cylinder option does not have a fifth cylinder. Early versions of this engine (2011-2013 models) are known for a specific manufacturing defect in the left cylinder head which can cause premature valve seat wear, leading to misfires. While TSB 09-002-14 primarily lists misfires for the left bank (cylinders 2, 4, and 6), the underlying valvetrain weakness can affect the entire engine. A more common issue across all years of the Pentastar, including the right bank where cylinder 5 is located, is rocker arm bearing failure. This failure often produces a distinct ticking sound and can lead to camshaft damage if not addressed.

Diagnostic Flowchart

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

Symptoms You May Notice

• Check Engine Light is on or flashing
• Rough or shaky idle
• Reduced engine power and poor acceleration
• Hesitation or stuttering when accelerating
• Increased fuel consumption
• A noticeable ticking or tapping sound from the engine, especially from the passenger side.

Most Likely Causes

1. Worn or Fouled Spark Plug 🔴 High Probability → Shop Spark Plug
   How to confirm: Remove the spark plug from cylinder 5 and inspect it for wear, oil fouling, or damage. Compare it to a plug from another cylinder. A healthy plug should have a uniform light brown color.
   Typical fix: Replace the spark plug. It is recommended to replace all six spark plugs at the same time for even performance. Ensure they are gapped correctly before installation.
   Est. part cost: $5-$20 per plug
2. Faulty Ignition Coil 🔴 High Probability → Shop Ignition Coil
   How to confirm: Swap the ignition coil from cylinder 5 with another cylinder (e.g., cylinder 3). Clear the codes and drive the vehicle. If the code changes to P0303, the ignition coil is faulty. This is a primary and easy diagnostic step.
   Typical fix: Replace the failed ignition coil.
   Est. part cost: $30-$75
3. Failed Rocker Arm / Lifter 🟡 Medium Probability → Shop Engine Rocker Arm The 3.6L Pentastar V6 is widely known for rocker arm bearing failures. The needle bearings in the roller can fail, causing the arm to seize or develop excessive play. This damages the camshaft lobe, leading to a misfire. This issue is so common it's often called the 'Pentastar Tick'.
   How to confirm: Listen for a distinct ticking/tapping noise from the top of the engine that increases with RPM. A visual inspection with the valve cover removed is needed to confirm a failed rocker arm, which may appear loose, off-center, or have a damaged roller.
   Typical fix: Replace all rocker arms and lifters on the affected bank (in this case, the right/passenger side bank). The camshaft must be inspected 🎬 Watch this walkthrough on replacing rocker arms and camshafts. for lobe damage and replaced if any scoring or wear is found.
   Est. part cost: $200-$400 for a full kit
4. Left Cylinder Head Failure ⚪ Low Probability → Shop Engine Cylinder Head 2012-2013 models are part of a range known for a manufacturing defect causing excessive valve guide/seat wear in the left cylinder head. Chrysler issued an extended warranty (X56) for this issue covering 10 years/150,000 miles. While P0305 is on the right bank, this known engine history is important context.
   How to confirm: If spark and fuel issues are ruled out, a cylinder leak-down test is required. TSB 09-002-14 specifies that leakage of 25% or more confirms 🎬 Watch: Advanced diagnostic steps for Pentastar valve train repairs. a mechanical engine fault requiring head replacement.
   Typical fix: Replacement of the left cylinder head assembly. This is a major repair. The updated part number is 68141353AC, which supersedes several previous versions.
   Est. part cost: $800-$1500
5. Faulty Fuel Injector ⚪ Low Probability → Shop Fuel Injector
   How to confirm: Swap the fuel injector from cylinder 5 with another cylinder. If the misfire code follows the injector, it is the cause. This is more labor-intensive than a coil swap as it requires removing the intake manifold. A technician can also test the injector's resistance, which should be around 12 ohms.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $50-$120

Rare But Worth Checking

• Vacuum Leak: A leak in a vacuum hose or the intake manifold gasket can lean out the air-fuel mixture and cause a misfire. This would typically affect more than one cylinder but can sometimes present as a single cylinder misfire initially.
• Low Compression: Beyond the specific cylinder head issue, general wear on piston rings or valves can cause low compression, leading to a misfire. A compression test will diagnose this.
• Clogged Catalytic Converter: While a misfire can damage a catalytic converter, a clogged converter can also increase backpressure and cause misfires, though it usually triggers other codes as well.

Diagnosis Steps

1. Use an OBD-II scanner to confirm P0305 and check for any other pending or stored codes. Note the freeze-frame data to see the conditions under which the misfire occurred.
2. Identify cylinder 5. On the 3.6L Pentastar, it is the rearmost cylinder on the passenger's side (right bank), closest to the firewall.
3. Listen for a distinct ticking noise from the passenger side valve cover area, which could indicate a failed rocker arm or lifter.
4. Swap the ignition coil from cylinder 5 with the coil from cylinder 3 (middle, passenger side). Clear the codes and run the engine to see if the misfire moves to cylinder 3 (code P0303). If it does, the coil is bad.
5. If the misfire remains on cylinder 5, remove the spark plug. Inspect it for wear, fouling, or incorrect gap. If it looks suspect, replace it. You can also swap it with another cylinder's plug to see if the code follows.
6. If the code remains P0305, inspect the wiring and connector for the ignition coil and fuel injector on cylinder 5 for any visible damage or loose connections.
7. If no obvious cause is found, a mechanical issue is more likely. Perform a cylinder compression test and a leak-down test on cylinder 5. Low compression or significant leakage (over 25%) points to a mechanical engine problem (e.g., rocker arm, camshaft, valve, or piston rings) likely requiring professional diagnosis and repair.

Parts You'll Likely Need

• Ignition Coil (OEM #5149168AH) — A common failure point for ignition systems that directly causes a single-cylinder misfire.
  Trusted brands: Mopar, NGK, Delphi
  OEM price range: $50-$80
  Aftermarket price range: $30-$60
• Spark Plug (OEM #SP142582AC) — Spark plugs are a routine maintenance item and will cause misfires when they wear out or become fouled.
  Trusted brands: Champion, NGK
  OEM price range: $10-$20
  Aftermarket price range: $5-$15
• Left Cylinder Head Assembly (OEM #68141353AC) — The definitive fix for the known manufacturing defect on early Pentastar engines that causes compression loss and misfires. This is the updated part number, superseding RL141353AC and others.
  Trusted brands: Mopar
  OEM price range: $1000-$1500
  Aftermarket price range: $800-$1200
• Rocker Arm & Lifter Kit (OEM #5184296AH (Rocker Arm), 5184332AA (Lifter)) — Addresses the common valvetrain ticking and misfire issue caused by failed rocker arm bearings. It is recommended to replace as a set for the affected bank.
  Trusted brands: Mopar, Mahle, Melling
  OEM price range: $300-$500
  Aftermarket price range: $200-$400

Related Codes That Often Appear With This One

• P0300 — If the misfire becomes more widespread or is intermittent across cylinders, a P0300 (Random/Multiple Cylinder Misfire) may be triggered alongside P0305.
• P0205 — This code indicates a fault in the cylinder 5 injector circuit. If seen with P0305, it strongly points to a problem with the fuel injector for cylinder 5 or its wiring.
• P0301, P0303 — These codes indicate misfires on other cylinders of the right bank (passenger side). Seeing them together with P0305 strongly suggests a problem affecting the entire bank, such as a clogged catalytic converter for that bank or a widespread valvetrain issue.

Technical Service Bulletins (TSBs) & Recalls

• 1810216: Lists various DTCs including P0305 - Cylinder 5 Misfire.
• 09-002-14 REV. B: Details the diagnosis (cylinder leakage test) and repair (replace left cylinder head) for misfire codes P0300, P0302, P0304, and P0306 on 2011-2013 models, including the Avenger, under the X56 Warranty Extension.

Platform-Specific Known Issues

• Extended Warranty (X56) for Left Cylinder Head: 2011-2013 models with the 3.6L engine, including the Avenger, were subject to a 10-year/150,000-mile extended warranty for a faulty left cylinder head that caused misfires (P0302, P0304, P0306). While this warranty may now be expired due to time, it highlights a well-documented factory issue. The associated TSB is 09-002-14, which instructs technicians to perform a leak-down test and replace the head if leakage is 25% or greater.
• Rocker Arm/Lifter Failure ('Pentastar Tick'): The 3.6L Pentastar engine is widely known for rocker arm bearing failure, which creates a distinct ticking sound. This failure can happen on either bank and is a common cause for single-cylinder misfires like P0305. The failed rocker often damages the camshaft lobe, requiring both to be replaced. This issue was the subject of a class-action lawsuit.

Mechanic-Grade Diagnostic Values

• Fuel Pressure — expected: 407 kPa +/- 34 kPa (59 psi +/- 5 psi). Failure: Pressure significantly below specification can cause lean misfires.
• Fuel Injector Resistance — expected: 12.0 - 16.0 Ohms. Failure: A reading significantly outside this range, or an open/short circuit, indicates a faulty injector. One real-world case showed a faulty injector reading over 60 ohms.
• Long Term Fuel Trim (LTFT) — expected: Close to 0%, within +/- 5%. Failure: A high positive percentage on Bank 1 (e.g., >10%) could indicate a vacuum leak or fuel delivery issue affecting cylinders 1, 3, and 5.
• Mode $06 Misfire Counter (Cylinder 5) — expected: Near zero during normal operation.. Failure: A high or rapidly increasing count confirms the PCM is actively detecting misfire events on cylinder 5, often before the check engine light becomes steady or flashes.

Scan Tool Commands That Help

• wiTECH (Chrysler/Dodge/Jeep Dealer Tool): Injector Kill Test — To confirm if a misfire is fuel-related. The technician can command the PCM to stop firing the cylinder 5 injector. If the engine's RPM and running characteristics do not change when cylinder 5 is killed, it confirms that cylinder was not contributing, pointing towards a problem with that cylinder's fuel, spark, or compression.
• wiTECH (Chrysler/Dodge/Jeep Dealer Tool): Misfire Counters — To view real-time and historical misfire counts for each individual cylinder. This is more detailed than generic Mode $06 data and can help identify intermittent misfires or misfires that occur only under specific load, temperature, or RPM conditions.

Wiring & Ground Locations

• Cylinder 5 Injector/Coil Harness — The main engine harness runs along the top of the engine. The injector wiring (Part # 5148037AM) and knock/oil/temp sensor wiring (Part # 5148105AH) are specific sub-harnesses.. The wiring for cylinder 5, being at the rear of the engine bay, can be exposed to high heat. A break or short in the injector or coil control wire will cause a P0305. Inspect the harness for chafing, melting, or brittle connectors.
• G308 — Right rear of the engine.. This is a primary engine ground. A loose or corroded connection at G308 can cause erratic behavior in sensors and actuators, including the ignition coils and fuel injectors, potentially leading to misfire codes.
• PCM (Powertrain Control Module) — Located in the left rear of the engine compartment.. All ignition coil and fuel injector commands originate from the PCM. A faulty driver circuit within the PCM, though rare, can cause a persistent P0305 that isn't resolved by replacing engine components. This is usually a last resort diagnosis.

Real Owner Repair Stories

• Reddit user post on a similar 3.6L Pentastar engine (2015 Jeep Wrangler 3.6L Pentastar) — P0303 (Cylinder 3 Misfire)
  ❌ Tried (didn't work) Swapped coil pack; misfire did not move., Swapped spark plug; misfire did not move.
  ✅ What actually fixed it An ohms test on the fuel injectors revealed the injector for the misfiring cylinder read 63.2 ohms, while a good injector read ~12 ohms. Replacing the single faulty fuel injector resolved the misfire.
• Dodge Journey Forum user 'looking for opinions' (2010 Dodge Journey 3.5L V6 (similar V6 architecture, different engine)) — P0305 Cylinder 5 misfire
  ❌ Tried (didn't work) Replaced ignition coil., Replaced spark plug., Used Sea Foam engine treatment., Used Mopar combustion chamber cleaner.
  ✅ What actually fixed it A compression test revealed the root cause. Cylinder 5 had only 60-70 PSI, while other cylinders were at 190 PSI. The final diagnosis pointed towards a mechanical failure, likely excessive carbon buildup on the valves or a bad rocker arm/lifter, requiring cylinder head service.

OEM Part Supersession History

• 5184296AD, 5184296AE, 5184296AF, 5184296AG → 5184296AH — Updated design to improve durability of the rocker arm, specifically the roller and needle bearings which were a common failure point causing the 'Pentastar Tick'.
  Heads up: All previous versions are superseded by 5184296AH. It is recommended to use the latest 'AH' version for repairs.
• 05184085AC → RL184085AC — Standard part number update and remanufactured part designation.
  Heads up: These part numbers refer to the fuel injector (Bosch 0280158233) and are interchangeable.

Model Year Variations Within This Range

• 2011-2013: These early model year 3.6L Pentastar engines are most susceptible to the left cylinder head failure due to valve guide wear, as noted in Pass 2.
• 2014+: Starting around 2014, changes were made to valvetrain components, including valve guides and seals, to improve longevity and reduce wear. While rocker arm failures can still occur, the widespread cylinder head issue is less prevalent in these later models.
• 2016+: A significantly updated version of the 3.6L Pentastar was released for 2016, featuring two-stage variable valve lift, a higher compression ratio (11.3:1 vs 10.2:1), and redesigned heads. While not in the 2012-2014 Avenger, it's important to note that parts like intake manifolds, injectors, and coils are not interchangeable with the earlier generation Pentastar.