On the 2.3L engine, above the oil filter there is an oil cooler that circulates oil by a water jacket. The original part is a Ford part and the gasket eventually hardens over time and fails, leaking massive amounts of oil on the ground. The issue could empty you engine of oil in a matter of minutes if the gasket failure is severe enough. Simply replacing the gasket is not enough, as replacement gaskets do not create a good enough seal. The leak will usually come back again within a few weeks or months. The permanent fix is to buy the oil cooler assembly that is manufactured in Japan and replace the Ford part for the Mazda Japan assembly oil cooler which costs a little more, but actually works. This will be built better and have a real rubber gasket that actually fixes the issue.

I bought a Mazda5 2008 used last year. It is no longer under warranty. The engine blew according to a Mazda dealer. They said no oil when checking the dip stick, but we know the car should have had oil. This is the cherry on top of many problems we have had with the car. These include: the air bag light kept coming on, the trans control module was replaced after 6 months of owning the car and car stalling, then the car continued to stall and our mechanic said it needed a new transmission (this was 2 weeks ago). I am frustrated because we are now responsible for the costs but we bought Mazda because we wanted a reliable car. :-(