2012 Yaris 1.4 D4D Frequent Economy Drop

[Beetle75]

Hi all

I recently bought a used 2012 1.4 Diesel from the Toyota dealership with ~37000 miles. I love the car and Im very happy with the economy since we bought it as a commuting car. I calculate from the last 2 fill ups we are getting ~65 MPG.

One thing seems a bit worrysome though. On a couple of occasions (had the car 1 month now) I will suddenly see the displayed average MPG falling fast under normal driving conditions (~2000 rpm, 50 mph) in 4th or 5th gear. I seem to be able to remedy this by dropping gear and reving to about 3000 rpm for a few seconds. Then the economy goes back to normal.

The turbo seesm to work well with very fast pick-up in 3rd and 4th. Im not expert in cars or engines Im afraid but from what I have read in these forums there could be some problem with the Turbo?

Any advice would be very much appreciated. I would like to catch something if its wrong before any danage is done. The car does have 2 years left on its warranty.

Thanks

[FROSTYBALLS]

The 1.4 D4D is subject to a recall currently - see the first post of the following thread, and use the link to the recall checker to see whether your car is affected:

http://www.toyotaownersclub.com/forums/topic/165486-recall-for-auris-yaris-urban-cruiser-iq-and-corolla/

[Heidfirst]

wonder if this could be caused by a DPF regeneration?

[Beetle75]

wonder if this could be caused by a DPF regeneration?

Hi. Thanks for your replies. I checked the link and my vehicle is not affected by any recemt recalls.

I read about the DPF and maybe thats what it is. But would the regeneration process be affacted by briefly increasing the rpms?

Thanks

[Devon Aygo]

wonder if this could be caused by a DPF regeneration?

Hi. Thanks for your replies. I checked the link and my vehicle is not affected by any recemt recalls.

I read about the DPF and maybe thats what it is. But would the regeneration process be affacted by briefly increasing the rpms?

Thanks

During DPF regeneration the car adds additional fuel into the engine which passes through the engine into the DPF and burns to clear the filter, whilst this occurs fuel economy will drop and the engines running will be altered. If at all possible when you notice this regeneration starting do not alter the way the car is driving, keep the speed above 50kmh and revs above 2500rpm. If you alter your driving habits the regeneration may be cancelled requiring another attempted regen soon.

[MEP's Yaris GS]

wonder if this could be caused by a DPF regeneration?

This would be the case normally, however OP states average MPG display, and not the instantaneous one. OP can you clear up which display you're referring to please.

This may help. I believe its not Fiat specific, and similar may occur in Toyota's with DPFs also.

[Beetle75]

wonder if this could be caused by a DPF regeneration?

This would be the case normally, however OP states average MPG display, and not the instantaneous one. OP can you clear up which display you're referring to please.This may help. I believe its not Fiat specific, and similar may occur in Toyota's with DPFs also.https://www.youtube.com/watch?v=Wq5sMAt2zS4https://www.youtube.com/watch?v=7uTfWsUJYPs

Hi. Both the average MPG and current MPG fall. The average slowly decreases and the current falls by 20 or so MPG.

I think next time it happens I will just not do anything and see if it recovers by its self in which case it might just be the DPF regeneration.

Thanks

[MEP's Yaris GS]

Sounds very much like a DPF regen now you've confirmed whats happening.

[Beetle75]

Hi

Happened again today. This time I didnt increase rpms and after 15 minutes it went back to normal. From a current average of 30 mpg to 60 mpg. It does seem like a DPF. Howeve when I take my foot of the accelarator it goes straight to 99.9 MPG unlike the car in the you tube video above.

Thanks to all for your suggestions. I dont think I have to worry about it.

[MEP's Yaris GS]

Howeve when I take my foot of the accelarator it goes straight to 99.9 MPG unlike the car in the you tube video above.

That may be a manufacture / software specific quirk :)

[MikeSh]

Howeve when I take my foot of the accelarator it goes straight to 99.9 MPG

That's the instant mpg, not the average.