Honda Pilot transmission and coolant fluid mixing issue due to valve failure at 120,000 miles on Honda Pilot

Some Honda Pilot owners report experiencing issues with coolant and transmission fluid mixing, often due to failures in the radiator or transmission cooler. For instance, a 2006 Honda Pilot owner noted this problem at 112,000 miles, incurring an average repair cost of around $1,250. In some cases, such failures result in transmission fluid contaminating the engine and coolant entering the transmission, making it difficult to completely clear the transmission system. Additionally, one driver faced a second transmission failure at 180,000 miles after an initial replacement under warranty at 35,000 miles, which also led to the mixing of fluids. Reports of transmission fluid mixing with coolant in the radiator have emerged, resulting in expensive repairs due to transmission failure. In a specific incident, a line failure caused antifreeze and transmission fluid to mix, necessitating the replacement of the radiator and coolant, as well as multiple flushes of the transmission. These experiences underscore the critical need for Honda Pilot owners to promptly address any signs of fluid mixing to avoid further damage and significant repair costs.