The application potential of ammonia fuel in internal combustion engines is significant; however, unburned ammonia and combustion products may enter the lubrication system, affecting tribological behavior of critical friction pairs. This study investigated the tribological behavior of the piston ring-cylinder liner (PRCL) pair at different temperatures by introducing aqueous ammonia into the lubricating oil to simulate the friction interface of ammonia-fueled engines. The results show that the effect of ammonia is highly temperature-dependent. At temperatures above 90°C, ammonia has minimal impact on lubricant performance and PRCL tribological properties. In contrast, at room temperature, ammonia significantly alters the properties of lubricants and induces corrosive wear on cast iron cylinder liners. It also changes the composition of the tribofilm, reducing its wear resistance. Nevertheless, friction is reduced at room temperature. This is likely because the increased presence of wear debris, including magnetite, catalyzes lubricant degradation during friction and promotes the formation of amorphous carbon on the worn surfaces. These findings provide insights into the effect of ammonia on lubrication and wear in ammonia-fueled engines.