Mazda SUV Range

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.

This sounds like a potentially very dangerous fault. Any car that wanders across the road or doesn’t go where the driver points it is an accident waiting to happen. A serious one, at that. At this point, the first piece of advice is to not drive the vehicle any farther and have it towed to a workshop for it to be inspected.

There’s one other possibility here. And that is that what you’re feeling is the car’s lane-keeping assistance program. This can often feel as though the steering it trying to plot its own course (which it is, in a way) in order to keep you centred in your lane. It only works up to a point, beyond which driver input will overcome it. I wonder if that’s what you mean by 'unsticking' the steering.

However, as far as I can tell, this model Mazda didn’t some with lane-keeping assistance (it has lane-departure warning only) so I think you’re back to square one and a tow-truck. Either way, this should be a warranty issue if there’s anything seriously wrong, so don’t be afraid to try a different dealership.

The sluggish performance and the erratic tachometer needle may not be related at all. That said, they could very well both be symptoms of the same problem. A lot of mechanics, when shown an erratic dashboard gauge, will start by checking for a bad earth point. A poor earth can lead to all sorts of problems, as a healthy flow of electricity is vital to the basic functions of any modern car.

But before you rush out to find an auto electrician, bear in mind that this sounds very much like a problem that would be covered by Mazda’s factory warranty. Provided you have had the car serviced correctly and it hasn’t been submerged in a flood or something equally drastic, the first step is to take it back to Mazda and allow the dealer to tackle the problem.