Excessive engine vibration or knocking noises heard while the engine is idling, being started or switched off are usually caused by a defective engine mount at the top right side of the engine. A redesigned engine mount is available to alleviate this problem.
Car Problem Reports
Mazda Mazda3 Defective Engine Mount May Cause Excessive Vibration/Noise
Mazda Mazda3 Problem
Average Mileage: 95,100 mi (67,500 mi - 112,800 mi)
Visitor, 2005 Mazda Mazda3, 67,500 mi
I am currently having this problem.It is getting progressively worse. Problem occurs on passenger side when idling with foot placed on brake.