One problem related to coolant leaking has been reported for the 1998 Cadillac Eldorado. The most recently reported issues are listed below.
Starting with dic message of "low coolant", I have experienced an engine overheating problem. After the Cadillac dealer in durango colorado was unable to find a problem ( replaced hoses, water pump), my mechanic (in albuquerque)found a cracked head that was leaking coolant internaly. Fixed the head, but now the head bolt holes stripped. Used oversized helicoils , but block material still to soft and cannot torque down the head bolts without pulling helicoils. Aluminum metal got to soft and have to replace the engine. This engin only has 82k+ miles and should not be doing this. Aluminium for block/head materia is stupidity. Weight savings cannot be that much to have shorter life of an engine. L.