A reader tip pointed us to an issue with Mazda's recent Skyactiv-D diesel engines in Australia. Apparently, the vehicle's particulate filter may be the source of some engine oiling issues. Our reader sent us this note regarding the issue
I’m really looking forward to the new skyactiv D engines coming to North America next year. As I was looking for info about them I came across issues with oil rising over the full mark. Seems to be caused by diesel leaking into the oil sump after being sprayed to burn off contaminates in the particulate filter (apparently this happens in other manufacturers diesels as well.) Most of the problems reported seem to be in Australia but apparently it is happening in Europe too. I know that the CX 5 Diesel is very popular in Japan but I didn’t find anything about the issue in JapanMazda sent out this leaflet to diesel owners regarding monitoring the oil, while forums have been alight with this topic. While some would-be owners have canceled their orders for CX-5 and Mazda 6 diesels, it appears that new engine software and a re-designed dipstick (which can give owners a more accurate reading of the oil level) can remedy the problem.