Mazda Reviews

The problem of the sump filling with diesel was not unknown on early CX-5 diesels. A leaking injector is possible, but the main cause of this was believed to be the car’s DPF regeneration process dumping large amounts of fuel into the engine, some of which finds its way past the piston rings and into the sump. Either way, a new engine is a large expense.

There’s every chance that Mazda won’t offer any help given the age of the vehicle, nor is this type of engine damage usually a cause for an insurance claim. It would definitely be worth contacting Mazda Australia’s customer service division, but don’t hold your breath.

Modern cars absolutely hate having low battery voltage. It throws everything into chaos and can easily produce the sort of problems you’re having as the major components of a car are, these days, all controlled by computers.

By turning the car off and on again, you’re effectively performing the old Alt-Ctrl-Del function to reboot a home computer or laptop. As such, and especially since the transmission works perfectly when you reset it, this is almost certainly an electrical problem. A more permanent reset might be needed, so try leaving the battery disconnected overnight and then reconnect it next morning. This will often return things to normal.

First things first: are you sure the leak is coming from the gearbox and not the engine? It can be very hard to discern the difference in a manual car, although it’s easier in an automatic as the transmission fluid is usually a red colour.

Beyond that, oil can escape from a gearbox through a variety of places. The breather could be allowing fluid out, the pan seal could be leaking, the rear gearbox seal could be faulty or you could even have a cracked transmission casing. Don’t rule out a leaking drain plug, either, as this is a very common source of a leak. You might even find the leak is coming from somewhere within the transmission cooler and its plumbing.