One problem related to engine funny noise has been reported for the 1997 Mazda 626. The most recently reported issues are listed below.
When the gear shift is in drive, and the brake is pressed, the car shakes violently and so much that it actually creates a humming noise. The vibration is so intense that it cause ears to clog up. Took car to browns mazad dealership, because still under warranty. Was told it was the motor mounts. They had my car for a total of two weeks, waiting on a "part" which happend to be a bolt and when I pick up the car, it was in worse condition than when I brough it in. I was told that the some vibration is normal, but I am literally shaking when the car idles in the drive gear. Nasty attitude. I am still covered under warranty and I asked to have the mounts replaced, but was told it was within 'specs' therefore, live with it. This could become a potential safety hazard, because I have to put the car in neutral gear to stop the shaking.