The 2018 Ram 1500 represents the final year of the fourth-generation model, featuring either the 5.7L HEMI V8 or 3.6L Pentastar V6. When your Ram 1500 displays P0304 indicating a cylinder 4 misfire, considering age-related wear patterns helps identify the likely cause.
Understanding P0304 in Your 2018 Ram
At this age, your Ram 1500 may have accumulated significant mileage where normal wear affects ignition and potentially mechanical components. Cylinder 4 is on the right bank in both HEMI and Pentastar configurations. The powertrain control module monitors each cylinder's contribution to identify misfires precisely.
Age-Related Considerations
Spark plugs may have exceeded their service interval and require replacement. Ignition coils can develop internal failures after years of heat cycling. On HEMI models, the Multi-Displacement System lifters may have accumulated wear—a well-documented issue on higher-mileage trucks that can cause misfires during cylinder deactivation.
Thorough Diagnosis
Given the vehicle's age, take a comprehensive approach. Inspect all ignition components rather than just cylinder 4. On HEMI models, evaluate MDS lifter condition if misfires occur during light-load cruising. Check compression to identify any mechanical wear. Verify fuel injector operation.
Repair Considerations
Replace all spark plugs as a set given the mileage. Test ignition coils and replace any showing weakness. On HEMI models with confirmed MDS lifter issues, options include individual lifter replacement or complete MDS delete. Ensure oil changes use correct specification oil for MDS operation.