Check the oil filled motor mounts carefully. They will leak and collapse. If the fan blades are worn down on the ends or the engine just sits there and doesn't move at all when idleing then the mounts are shot and the engine pan is resting on the frame. Probably the most important thing to look at is signs of head gasket leakage. High mileage (>175k) turbos can blow head gaskets. Concider this if there's any signs of oil or coolant leakage around the cylinder head gasket. Take the car on a drive up a long hill if possible. Try to keep the turbo gauge in the boost (yellow) area at least 5-10 seconds to be sure the turbo isn't starting to go bad. If the needle suddenly drops down out of the yellow area and you loose power the turbo has started to seeze up. This is another expensive repair. '89 is probably one of the better years for the 740's. A good one will last a long time.