P0307 on 2011-2018 Ram 1500 5.7L Hemi: Cylinder 7 Misfire Causes and Fixes

What's Unique About the 2011-2018 Ram 1500

On the 5.7L Hemi V8, a P0307 code isn't always a simple ignition problem. These engines are equipped with a Multi-Displacement System (MDS) that deactivates four cylinders, including cylinder 7, to save fuel under light load. This system uses special hydraulic lifters that are a notorious weak point. The roller bearing on the MDS lifter can seize or the lifter itself can collapse, causing a loss of valve lift and a persistent misfire that won't be fixed by replacing ignition parts. This failure often results in the lifter's roller grinding against the camshaft, destroying the lobe and requiring replacement of the camshaft, all lifters, and associated gaskets—a common and expensive repair for this engine.

Symptoms You May Notice

• Solid or flashing Check Engine Light
• Rough or shaky idle
• Hesitation or stumbling during acceleration, especially under heavy load like going uphill.
• Noticeable loss of engine power
• Audible ticking or tapping noise from the engine, known as the 'Hemi tick', often loudest near the driver's side firewall.
• Reduced fuel economy
• Engine may disable the MDS and remote start features

Most Likely Causes

1. Worn or Fouled Spark Plugs 🔴 High Probability → Shop Spark Plug The 5.7L Hemi uses two spark plugs per cylinder (16 total), increasing the statistical chance of a single plug failing. They are a regular maintenance item, with a 30,000-mile interval for the stock copper plugs used until 2014 models. Fouling can occur from oil consumption or rich/lean conditions.
   How to confirm: After ruling out the coil, remove the two spark plugs from cylinder 7. Inspect for a worn electrode, cracked porcelain, or heavy carbon/oil deposits. Compare to a plug from a working cylinder.
   Typical fix: Replace the spark plugs. It is best practice to replace all 16 spark plugs at the same time for even performance. Use the correct type (copper vs. iridium) specified for your model year, as the ignition systems differ.
   Est. part cost: $60-$150 (set of 16)
2. Faulty Ignition Coil 🔴 High Probability → Shop Ignition Coil
   How to confirm: Swap the ignition coil from cylinder 7 with another cylinder (e.g., cylinder 1). Clear the codes and drive the vehicle. If the code changes to P0301, the ignition coil is faulty.
   Typical fix: Replace the faulty ignition coil. It is recommended to use a quality OEM (Mopar) or reputable aftermarket brand. The original part number 56029129AF was later superseded by 68238603AA.
   Est. part cost: $40-$80
3. Failed MDS Lifter and/or Worn Camshaft Lobe 🟡 Medium Probability → Shop Engine Camshaft This is a widely documented failure point on the 5.7L Hemi. The roller bearing on the MDS lifter (especially on an MDS cylinder like #7) can fail, causing the lifter to stop rotating and grind a flat spot on the corresponding camshaft lobe. This prevents the valve from opening properly and is often preceded by a ticking noise.
   How to confirm: If ignition and fuel system checks do not resolve the misfire, a mechanical issue is likely. Listen for a persistent ticking noise with a stethoscope near the cylinder 7_valve cover. Perform a compression test on cylinder 7. The definitive check involves removing the driver's side valve cover to inspect the valvetrain for cylinder 7, looking for a rocker arm that is loose or has no movement while the engine is cranked.
   Typical fix: This is a major repair that involves replacing the camshaft, all 16 lifters (both MDS and standard), pushrods, head gaskets, and timing components. Many owners opt to install a non-MDS camshaft and lifters and use a tuner to disable the MDS system.
   Est. part cost: $800-$2500+
4. Faulty Fuel Injector ⚪ Low Probability → Shop Fuel Injector
   How to confirm: After ruling out ignition components, swap the fuel injector from cylinder 7 with another cylinder. If the misfire code follows the injector, the injector is bad. You can also use a 'noid light' to confirm the injector is receiving an electrical pulse from the PCM.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $50-$150

Rare But Worth Checking

• Intake Manifold Gasket Leak: → Shop Engine Intake Manifold A vacuum leak near the cylinder 7 intake runner can lean out the air/fuel mixture enough to cause a misfire. This can be diagnosed with a smoke test.
• Broken Valve Spring: While less common than lifter failure, a broken valve spring can cause a loss of compression and a severe misfire. This would be visible upon removing the valve cover and has been reported by owners.
• PCM Software Issue: Chrysler has released TSBs like #18-084-16 and #18-022-21 for some model years to update PCM software for overly sensitive misfire detection. It's worth checking with a dealer if any apply to your VIN.
• Wiring Harness Damage: The wiring for the cylinder 7 coil and injector runs near the back of the engine on the driver's side. Heat or chafing can damage these wires, causing an intermittent or persistent misfire. A visual inspection and continuity test may be required.

Diagnosis Steps

1. Read the codes with an OBD-II scanner and confirm P0307 is the primary code. Note any other codes present, especially MDS-related codes (P34xx).
2. Listen for an audible ticking noise from the driver's side of the engine bay. A persistent tick that increases with RPM is a strong indicator of a mechanical lifter/camshaft issue.
3. Swap the ignition coil from cylinder 7 (rearmost, driver's side) with cylinder 1 (front, driver's side). Clear the codes and drive. If the code changes to P0301, the coil is bad.
🎬 See how to swap coils and plugs to find a misfire.
4. If the code remains P0307, swap the two spark plugs from cylinder 7 with the plugs from cylinder 1. If the code moves to P0301, the plugs are the issue.
5. If the code remains P0307, inspect the fuel injector. Check for a pulse with a noid light. For a definitive test, swap the injector with another cylinder and see if the misfire follows.
6. If ignition and fuel checks pass, perform a compression test on cylinder 7. A significantly low reading (more than 20% lower than other cylinders) indicates a mechanical problem like a bad valve, piston ring, or valve spring.
7. If a tick is present or compression is low, remove the driver's side valve cover. Inspect the valve springs for breakage and watch the rocker arms for cylinder 7 while the engine is manually cranked. Lack of movement or excessive looseness indicates a collapsed lifter and likely a wiped camshaft lobe.
🎬 Watch this walkthrough of a Hemi camshaft and lifter replacement.

Parts You'll Likely Need

• Ignition Coil (OEM #56029129AF (superseded by 68238603AA)) — Ignition coils are a common failure item that directly cause a single-cylinder misfire.
  Trusted brands: Mopar, NGK, Delphi
  OEM price range: $50-$80
  Aftermarket price range: $30-$50
• Spark Plugs (OEM #SPLZFR5C11 (NGK Copper, pre-2014) or NGK Iridium for 2014+) — As a standard maintenance item, worn or fouled spark plugs are a primary cause of misfires. The Hemi uses 16, making individual failure more likely.
  Trusted brands: NGK, Champion
  OEM price range: $100-$150 (set of 16)
  Aftermarket price range: $60-$120 (set of 16)
• Camshaft and Lifter Kit (OEM #MDS Lifters: 5038785AD. Non-MDS Lifters: 5038784AD.) — Required for the common 'Hemi tick' failure. A persistent P0307 not solved by ignition/fuel parts is a strong indicator that this major mechanical repair is needed. The kit should include the camshaft, 16 lifters, head gaskets, and bolts.
  Trusted brands: Mopar, Melling, COMP Cams
  OEM price range: $1200-$2000 (for parts kit)
  Aftermarket price range: $800-$1500 (for parts kit)

Related Codes That Often Appear With This One

• P0300 — If the cause of the misfire (like a failing lifter) begins to affect other cylinders or if there's a widespread fuel delivery issue, a P0300 (Random/Multiple Cylinder Misfire) code may appear alongside P0307.
• P3449 — This code means 'Cylinder 7 Deactivation Control Circuit'. Its presence with P0307 strongly points towards an issue with the MDS system (lifters, solenoids) as the root cause of the misfire. TSBs confirm this link.

Technical Service Bulletins (TSBs) & Recalls

• TSB 18-084-16: Involves a PCM software update to address several falsely set DTCs, including P0307, and to improve MDS mode transitions.
• TSB 18-022-21: For 2020 models but relevant, this TSB involves a PCM flash to correct issues causing misfire codes across all cylinders (P0300-P0308), including rough idle after a cold start.
• TSB 18-031-14 Rev. A: While for a Jeep Cherokee, this bulletin shows a history of Chrysler addressing false P0300-level misfire codes via software updates, which can be relevant context.
• TSB Bulletin #18-002-25: Notes that P0307 can occur alongside P0300, P0301, P0304, and P0306, as well as MDS-related codes like P3400 and P3497.
• TSB Bulletin #1814522: Lists P0307 as a potential diagnostic trouble code that may appear in conjunction with B2286 regarding lost or unlearned calibration.
• TSB Bulletin #1800624: Indicates that customers may experience an engine misfire and P0307, requiring a software reprogramming procedure to resolve.

Platform-Specific Known Issues

• The most significant issue tied to this code on the 5.7L Hemi is the failure of the Multi-Displacement System (MDS) lifters. This is a well-documented problem that can cause a misfire code before leading to more severe engine damage if ignored. Forum discussions frequently link a 'Hemi tick' that progresses to a P030X misfire code, ultimately requiring lifter and camshaft replacement.

Mechanic-Grade Diagnostic Values

• Ignition Coil Primary Resistance — expected: 0.558 - 0.682 Ohms at 70-80°F. Failure: A reading outside of this range indicates a faulty coil.
• Fuel Injector Resistance — expected: ~11.5 - 12.5 Ohms. Failure: A significantly higher or lower reading, or an open circuit (O.L.), points to a failed injector.
• MDS Solenoid Resistance — expected: 10.3 Ohms at 68°F. Failure: A reading significantly different from the specification suggests a faulty MDS solenoid.
• Fuel Pressure (Key on, Engine off or running) — expected: Approximately 58 PSI for 2004+ models. Failure: Significantly lower pressure (e.g., 35 PSI) indicates a weak fuel pump or regulator issue.
• Engine Compression — expected: Approximately 180-220 PSI, with less than 20% variation between cylinders.. Failure: A reading on cylinder 7 that is significantly lower (e.g., 150 PSI when others are 220 PSI) points to a mechanical issue like a worn cam lobe or poor valve seating.

Scan Tool Commands That Help

• Chrysler wiTECH: Misfire Counters — To monitor live misfire events on cylinder 7 during a test drive under specific load conditions (e.g., going uphill) where the symptom is most prevalent. This confirms the PCM is actively detecting the fault when it happens.
• Chrysler wiTECH: Cylinder 7 MDS Solenoid Actuation — When P3449 is also present, this bidirectional command can be used to manually activate the solenoid. An audible click should be heard. Lack of a click or no change in engine behavior can help isolate a faulty solenoid or its wiring.

Wiring & Ground Locations

• Cylinder 7 Ignition Coil Control Wire — At the Powertrain Control Module (PCM) connector. For a 2011 model, this is a Dark Blue/Tan wire.. If the ignition coil and spark plug are good, a break or short in this specific wire between the PCM and the coil will prevent the coil from firing, causing a persistent P0307. A continuity test on this wire is a critical step before condemning the PCM.
• Engine Ground Strap — Typically located from the engine block to the chassis frame rail on the driver's side.. A poor or corroded main engine ground can cause a variety of electrical issues, including weak spark. While it would likely cause multiple random misfires (P0300), it can sometimes manifest as a single-cylinder misfire initially if that cylinder's circuit is most sensitive to the voltage drop.

Real Owner Repair Stories

• RamForum.com user 'KDL' (2011 Ram 1500 5.7L Hemi) — P0307 code, engine runs fine under normal load but sputters badly under heavy load (uphill/passing). Also had a persistent 'Hemi Tick' loudest over cylinder #7.
  ❌ Tried (didn't work) Changed spark plugs, Replaced #7 ignition coil, Visually inspected valve springs (appeared okay), Swapped fuel injectors between cylinder #1 and #7
  ✅ What actually fixed it The final fix was a complete camshaft and lifter replacement. The #7 lifter had failed and wiped the corresponding lobe on the camshaft, which was the root cause of the misfire under load.
• DodgeForum.com user (2017 Ram 1500 5.7L Hemi with 22,000 miles) — Recurrent P0307 check engine light, sometimes accompanied by lower performance and higher fuel consumption.
  ❌ Tried (didn't work) Dealer reset the code multiple times, Dealer re-flashed the PCM software
  ✅ What actually fixed it The user was advised by other forum members that this is a classic symptom of an impending lifter/cam failure, even at low mileage, and to push the dealership for a mechanical inspection of the valvetrain under warranty rather than accepting software flashes.

OEM Part Supersession History

• 53021726xx, 68060714AA, 5038785AB → 5038785AD — Revisions to improve the reliability of the MDS lifter assembly.
  Heads up: While all are for the 5.7L Hemi, it is critical to use the latest revision (5038785AD) when replacing failed lifters to get the most updated design. Using old stock or a mix of old and new part numbers is not recommended.

Model Year Variations Within This Range

• 2014-2018: Starting in the 2014 model year, the 5.7L Hemi switched from copper resistor spark plugs (30,000-mile interval) to longer-life iridium plugs (100,000-mile interval). Using the wrong type of plug can affect ignition performance and longevity.
• 2013: The 2013 model year introduced a refreshed interior and exterior, and was the first year the 8-speed automatic transmission became more widely available with the 5.7L Hemi, though the core engine design and its vulnerabilities (like lifter failure) remained the same as earlier years in the range.

Diagnostic Flowchart

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0301 — Often appears during diagnosis when swapping the ignition coil or spark plugs from cylinder 7 to cylinder 1 to verify if the misfire follows the component. TSB Bulletin #18-002-25 notes P0301 can appear alongside P0307.
• P0300 — Random/Multiple Cylinder Misfire. TSB 18-022-21 and TSB 18-031-14 Rev. A note that PCM software issues can cause false misfire codes across all cylinders, including P0300 and P0307.
• P3400 — Represents MDS-related codes (P34xx). These frequently accompany P0307 if the root cause is a collapsed Multi-Displacement System lifter on cylinder 7. TSB Bulletin #18-002-25 confirms this link.
• P0308 — Mentioned in TSB 18-022-21 alongside P0307 as part of a range of misfire codes (P0300-P0308) that may require a PCM flash to correct rough idle issues after a cold start.

Frequently Asked Questions