If Dexcool was such a bad coolant, as some people have said it is, it would start to attack the intake gaskets as soon as it was poured into the cooling system. That’* not the case, nor does that occur with any other brand of long life coolant. The problem is not the brand or type of coolant in the cooling system. The problem is any type of corrosion inhibitor will eventually wear out. Once this happens, the coolant becomes acidic and allows corrosion to attack the metal surfaces around the coolant ports as well as the intake manifold gaskets.