Chevrolet Impala DexCool antifreeze causing recurring sludge buildup in cooling system on Chevrolet Impala

Some Chevrolet Impala owners report experiencing recurring sludge buildup in the cooling system due to the use of DexCool antifreeze. This sludge formation can lead to significant cooling system issues, and mixing DexCool with green antifreeze is known to exacerbate the problem by creating a brown sludge in the radiator. Many owners have raised concerns about corrosion and clogging associated with DexCool, which can also deteriorate plastic intake gaskets and potentially cause antifreeze leaks into the engine. Furthermore, flushing the cooling system may not fully eliminate DexCool sludge, and in severe cases, radiator replacement might be necessary. It is crucial for owners to avoid mixing DexCool with conventional green coolant to prevent sludge formation that could clog the cooling system. While DexCool is designed for a longer lifespan with a change interval of every five years, mixing it with non-OAT coolant can significantly reduce this interval to just two years or 30,000 miles, highlighting the importance of proper maintenance and coolant selection.