zero1342

2009 (series 2) Manual with ~35k miles (bought used).

About 3-4 months ago I noticed the coolant was not at the full line and since then have had to add coolant 3-4 times. Each time the coolant has either been at the L line or a bit above it. Two weeks ago I added fluorescent dye to track down the leak and then got in there to look around. I attached pictures of what I discovered.

There was coolant that had collected around the passenger side of the engine down around the top of the oil pan. I didn't find anything around the water pump, thermostat or on the associated coolant hoses and nothing up around the radiator. And the location of where I found the coolant is behind and below the water pump so I don't see how a leak starting there would get to the region around the oil pan without leaving a trail. I took out the battery, oil pan rock guard and splash shield to get in there and get a good look.

I'm concerned that the leak is actually due to a blown water seal between one of the irons and the front rotor since I haven't been able to find an external leak source, however there is no coolant in the oil (checked dip stick) and no smoke comes out the back.

Also the car is completely up-to-date on everything and the coolant was completely flushed last year when I replaced the coolant reservoir due to a Mazda bulletin. I've been using one of the PEAK brands of 50/50 coolant (Maryland) since that flush.

Any ideas? I've also included a pic of a bare engine for reference. You can use the horizontal threads on the bolt in my pic to match up the location on the bare engine pic. Thanks for any help!