One problem related to engine cooling system has been reported for the 1998 Cadillac Seville. The most recently reported issues are listed below.
Sudden erratic readings such as engine hot, ac off, and service engine soon light on. Engine reduced cylinder operation to 4 cylinders, power reduced significantly. Family in car and heavy traffic could have been dangerous situation in both cases. Found blown head gaskets and coolant entering into 2 cylinders. Mileage only 70,343.