One problem related to water pump has been reported for the 2000 Cadillac Deville. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2000 Cadillac Deville based on all problems reported for the 2000 Deville.
Engine began overheating and took it to our mechanic who replaced the water pump. Engine continued to overheat and same mechanic replaced all of the upper seals. Eventually, a pressure test and camera insert by my mechanic confirmed a blown head gasket. Confirmed that result with pepe Cadillac in white plains, NY. Checked the price to have the head gaskets replaced, but since this engine has to be removed from the bottom of the vehicle, the costs are outrageous and the only acceptable fix for these aluminum heads are bolts rather than the gm serts. Bad engine design by gm since their bolts were too short and the bite was not large enough in the block to prevent the head gaskets from blowing. Sad epitaph for a car with only 65k lightly driven miles on it having spent all of it's off road life in our garage. After much research, I was able to confirm that this is an inherent problem with the northstar engine during that period and was finally solved after 2004. Gm knows about the engineering northstar engine problem but refuses to accept responsibility for it.