2016 CX-9 with 91,000 miles.
I noticed the coolant level in the tank was consistently low, even after adding more. After a week of repeatedly topping off the coolant every other day, I removed the engine undercover and discovered a messy green residue all over the place. I contacted MazdaUSA and confirmed that my 2016 CX-9 is still covered under the CPO Limited Powertrain Warranty until 7/28/23 or 100,000 miles, which is just about another two months in my case. Initially, I suspected a leaking water pump or gasket when I brought it to my local dealer. However, they informed me that it's actually a crack in the cylinder head. Fortunately, this issue will be covered by my CPO warranty, but I'll have to wait for a week to get the replacement part. In the meantime, I'm using the dealer's courtesy vehicle for free since the loaner car is not covered by Mazda. I'm uncertain about how long I should remain optimistic. I had plans to continue driving my CX-9 for a long time, but now I'm not sure what to expect.
