Mazda Repair Questions? Ask Mechanics for Answers ASAP
I think you may have torn the transmission motor mount. The mount is on the driver's side on top of the transmission. It may have torn when you hit the puddle, or it was just then when you began to notice it. It is loudest when the AC is on because it requires more torque form the engine because of the increased load from the AC compressor. The easiest way to tell if the mount is out is to look at the mount and see if it is covered in rubber bits. It's tough to see because it's under the battery box, but you can usually sneak your and underneath it and pull it out covered in rubber from the mount.
The noise from this mount is occasionally confused for an exhaust leak because of the rattling noise it makes which gets worse as it wears out.
I think it might just lessen as the vehicle warms up because it requires less torque to get the vehicle to move when the engine is at operating temperature. The first time I saw one of these I changed the rear mount, and front mount thinking it was one of them even though they both looked fine. Then when it persisted I finally realized there was a third mount- the transmission mount on the driver side. I changed it and the noise was gone.
Yeah, let me know how it looks. I've changed about 20 or so of those mounts since the first time I discovered it.
Yeah, I would agree; that mount does look a little worn. I would still change that transmission mount also, just from experience. My fleet has about 200 ford focuses and 4 cylinder fusions and they have the exact same engine and mount set-up and it seems like we have changed all of the mounts at some point.
I also found this TSB from mazda. Might be a good place to check as well.
Turning the wheel probably just puts extra load on the engine from the power steering pump and/or shifts things around so that the worn part on the mount is vibrating against metal on the frame.
I'm glad I could help! Let me know if you need any more advice.