Two problems related to engine have been reported for the 2005 Mazda MAZDA3. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Mazda MAZDA3 based on all problems reported for the 2005 MAZDA3.
2005 Mazda 3 hatchback with 55k miles had engine mount crack. Quick search online appears this is a common problem.
My Mazda3 2005 has had an a/c compressor problem. This expensive part has been replaced 4 times to no avail. It fails again every time, and Mazda insists there is no problem with the part.