Chrysler Pacifica coolant leak and cylinder #5 misfire issue on Chrysler Pacifica

Some Chrysler Pacifica owners report experiencing coolant leaks, particularly in the 3.6-liter engine, which can lead to overheating, loss of cabin heat, and potential engine damage. These coolant leaks may result in coolant seeping into the cylinder, causing a misfire, specifically noted in cases of a gasket leak. Owners have identified cylinder #5 misfires indicated by the OBDII code P0305, which points to issues in that cylinder. Possible causes for this misfire include faulty spark plugs, ignition coils, fuel injectors, vacuum leaks, low compression, or timing issues. To diagnose the specific cause of a cylinder misfire, some owners report swapping components like spark plugs, coils, and injectors, while monitoring misfire data with a scan tool. Addressing these misfire issues may require replacing components and conducting thorough diagnostic tests to identify and resolve the underlying causes, including any coolant seepage into the cylinder.