One problem related to radiator has been reported for the 2013 Mazda CX9. The most recently reported issues are listed below.
The radiator failed internally with no warning, no leaks no engine light nothing, mixing antifreeze into the oil and destroying the engine. My machine informed me that there was no way of me knowing this was happening and its faulty the way they make the radiator it causes this to happen. Now my radiator is bad and my engine. I was driving and suddenly a noise started then power went and pulled over and wouldn't start again. No warning nothing. No leaks no engine light prior.