Ford F-150 antifreeze smell when running, suspected issue with coolant reservoir O-ring on Ford F-150

Some Ford F-150 owners report experiencing an antifreeze smell while running, which may indicate issues with the coolant reservoir O-ring or other components. These owners often find it necessary to check the overflow reservoir for coolant levels, ensuring they are within the recommended range. Additionally, some report inspecting the A/C drain tube for antifreeze drips, which could suggest problems with the heater core. In cases of small leaks in the heater core, owners may notice a smell without visible antifreeze, often accompanied by dark residue due to evaporation. To diagnose the issue, some owners perform pressure tests on the cooling system to identify leaks or pressure loss. Caution is advised when checking the reservoir cap while the engine is warm to avoid sudden pressure release. If the heater core is the source of the problem, some owners find that replacing it requires dashboard removal, indicating the complexity of the task. Furthermore, those affected by a recall related to the powertrain control module can access free reprogramming services by contacting Ford customer service for more information.