What is the valley-plate coolant leak issue on the 2019-2023 Lexus GX460 and what does it involve?
The 2019-2023 Lexus GX460 with the 4.6L V8 can develop a coolant leak in the valley between the cylinder banks, often from the valley-pipe O-rings or gaskets under the intake manifold. Symptoms include a sweet coolant smell, dropping coolant level with no obvious external leak, a possible low-coolant warning, and eventual overheating if ignored. The 2024 and newer GX550 uses a different twin-turbo V6 and is not affected by this specific issue. Repair typically requires removing the intake manifold and replacing the valley gaskets or O-rings.
Estimated repair cost: $2,650.00