Was it running on three cylinders?

[Biker_Rob]

Had it for 3 weeks and delighted with it.

The fuel consumption exceeds what I expected and I find myself always in the fuel consumtion monitoring screen and I have the dash readout set to the instant consumption. After staring at it for 3 weeks and 500 miles I know what to expect in all normal conditions.

Today it started to give really bad fuel consumption - about 60% of what I'd expect in mpg.

Then I became aware of other symptoms:

1. Idling a bit lumpy - hard to spot becasue its so smooth anyway, but definitely not right.
2. Istop not working (no I didn't look at the Istop screen - I didn't know where to find it at the time)
3. No temp warning during driving but the fan running on when exiting the car - this is with ambient at 10C and I've never experienced it at all before.
4. If you freewheel in Neutral (please no advice from Advanced Motorists), normally the instant fuel consumption meter tops out at 170mpg within about a second, but in this mode it doesn't even top out at all - it can be all over the place when coasting.

So I let it cool down and went out for another drive. Same again.

Then while on the 2nd test run after about 8 miles as if by magic, it goes back to normal. All symptoms gone.

Something was definitely not right but I'm hoping it was some aberation like foreign matter in an injector or something. If it happens again I'll be off to the dealer.

Anyone had this?

While I'm here, I'll mention something else. Is it me being dumb or is there no easy way to stop the audio player? I use a USB stick and its easy enough to mute it but it carries on playing without sound and you lose where you were up to - why don't they just make the function of the 'Mute' to be 'Pause & Mute' - that would fix it. The pause on the audio screen is too much fiddling if you're not already on that screen.

[st3v3cx-3]

Regarding the USB, I think this has been raised by other forum members and the answer was that there is no way to stop/pause the audio player. Might also apply to the CD although I've never used it so can't confirm. Perhaps Mazda might alter the mute function accordingly in due course - ideally via an infotainment software upgrade.

Hope the engine quirks referred to by anchorman's posting below don't spoil your enjoyment of your newly acquired CX-3.

[Edited 16-4-17: Removed comments about engine as explained by a subsequent user's posting]

[Deleted User 406]

You can pause the USB on the display using the control wheel.

[anchorman]

It's perfectly normal and all of the diesels do it - very often unnoticed.

It's regenerating the DPF (diesel particulate filter) and will do it every 150-200 miles. During this time, it pumps neat fuel into the exhaust and super heats the carbon caught in the filter. If you happen to be driving continuously during the process, the only thing you are likely to notice is that it sounds a bit throaty on overrun and that the istop is cancelled during the process. You may get a smell of burning if you come to a stand and as you've noticed, those fans run continuously. If you watch your instant economy, you'll find it goes through the roof as there is a price to pay! Another aspect is that if you interrupt it like you did when the fans kept running, it will dilute the sump oil so you are advised to keep an eye on that. There is an X on the dipstick above the normal 2 marks. If it gets to that, the oil needs changing or it may warn you on the dash as it measures viscosity.

[UKDucatiman]

It's perfectly normal and all of the diesels do it - very often unnoticed.

It's regenerating the DPF (diesel particulate filter) and will do it every 150-200 miles. During this time, it pumps neat fuel into the exhaust and super heats the carbon caught in the filter.

And that's good for the environment, right

[anchorman]

It's perfectly normal and all of the diesels do it - very often unnoticed.

It's regenerating the DPF (diesel particulate filter) and will do it every 150-200 miles. During this time, it pumps neat fuel into the exhaust and super heats the carbon caught in the filter.

And that's good for the environment, right

Well, I’m no chemist but apparently, guzzling fuel to burn off carbon is the lessor of two evils. I find it bewildering too.

[Biker_Rob]

Well thanks anchorman for the comprehensive explanation. It's put my mind at rest and I'll look out for it next time. I'm sure the Developers at Mazda argued with the Marketeers about whether its a good thing to have an indication on the dash when this process is occuring.

[anchorman]

Yes it would be useful but some people go into meltdown when they see a warning light so I can also see why they don't. I just go off the sound of the engine and the fact the istop doesn't work. If it happens while I'm hoofing down the motorway then I guess it hadn't effected me