One problem related to engine exhaust system has been reported for the 1997 Buick Park Avenue. The most recently reported issues are listed below.
The plastic air plennom on the top of the 3800 engine of the newer gen motors cars that they are now using will not hold up under the heat. The egr tube which extends up into the plastic air intake burns a hold into the cooling system surrounding the egr tube, causing coolant to drian into the the motor intake chamber. In turn, the coolant then mixes with the oil and ruins the motor rod bearings. I have already replaced one motor and am now experiencing similar trouble with the second motor for the same problem. They need to go back to the metal air intakes!.