Mazda CX-5 Forums
Technical Section => Engine/Transmission/Powertrain/Exhaust => Diesel and DPF issues => Topic started by: Deeps on October 28, 2015, 02:33:48 pm
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This is a somewhat lengthy video but explains in depth how DPF regeneration works with mention also being made to Mazda's take on the issue.
https://youtu.be/fNO-oUHmKXU
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Earlier today, with 1,025 km's on the clock, my CX-5 went through it's second regeneration. With the first taking place at a touch over 500km this appears to bear out my suspicions that Mazda have programmed the firmware to execute a regeneration cycle at the 500 km+/- mark irrespective of the current state of the filter.
This second regeneration was very short in duration and the awful smell that was evident first time around was more acceptable to the nasal passages lol. Whether this was due to my top-up fuel fill being with a so-called better grade of diesel or because the engine had now had a few km's put on the clock I wouldn't like to say.
As an aside - the engine oil level dropped by a couple of millimetres upon checking after the first 500km but remains at the same level with now 1,090km on the clock so oil consumption at this moment in time is negligible. From an appearance aspect, the viscosity appears to be the same i.e. feels like undiluted oil on the fingers, and the colour is as new with no smell of diesel present.
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Earlier today, with 1,025 km's on the clock, my CX-5 went through it's second regeneration. With the first taking place at a touch over 500km this appears to bear out my suspicions that Mazda have programmed the firmware to execute a regeneration cycle at the 500 km+/- mark irrespective of the current state of the filter.
This second regeneration was very short in duration and the awful smell that was evident first time around was more acceptable to the nasal passages lol. Whether this was due to my top-up fuel fill being with a so-called better grade of diesel or because the engine had now had a few km's put on the clock I wouldn't like to say.
As an aside - the engine oil level dropped by a couple of millimetres upon checking after the first 500km but remains at the same level with now 1,090km on the clock so oil consumption at this moment in time is negligible. From an appearance aspect, the viscosity appears to be the same i.e. feels like undiluted oil on the fingers, and the colour is as new with no smell of diesel present.
How are you able to tell the regeneration is happening? I have done nearly 7000 miles and have not noticed anything out of the ordinary happening during any journey.
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There are a few clues really - (1) if you've set the OBC to read fuel consumption (actual not average) then this will rise for a short period although your speed hasn't increased - assuming you're not accelerating of course. (2) there will be a sort of burning smell a bit similiar to the smell you get with a new heating/toaster element and (3) if you spot any of the last two, then look through the rear view mirror and you might catch a cloud (a puff really) of white smoke - similar but obviously not the same as the black stuff when really giving some throttle to a diesel engine.
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Hi, after reading this post maybe I have a concen. My Cx5 diesel averages between 48 to 52 mpg then at regular intervals the average consumption will drop to 42ish, normally when off the throttle going down hill the instant mpg reading is zero, when this event happens its between 20 to 25mpg on the same off throttle down hill conditions. This seems to happen every 200 to 300 miles.
Iv noticed this happing even on really long runs,over 500 mile plus. The car does hardly any runs less than 20 miles ever. Am I being fussy or do you think there is something wrong..
Iv had many diesel cars and iv never had this before.
H
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Sounds normal to me Howard. Apart from the zero reading down hill i thought mine read 99 mpg off throttle, but rarely use anything but the average read out. CX-5 has a timed regen about 250 miles.
Only once have i seen a cloud of smoke through the rear screen, just as i was pulling into my drive!
My instantaneous readout DROPS when i have a PDF burn. :)
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Why can't we have a DPF regen warning on the display? My car nearly always regens (that I've noticed) when I'm on the way home from work, it seems that the last mile drag uphill provides the ideal throttle/temperature etc conditions for it to happen but the first I notice is when I park up on the drive & the car doesn't go in to iStop mode. My neighbours must think I'm a bit mental because I then have to get out of the car & sniff around it to see if I can smell the tell tale burning smell, if I do I then jump back in the car & drive around for 10 minutes when all I
really want to do is go indoors for a cup of tea! The cars computer knows it's doing it so it can't be that hard for Mazda software bods to write some code to display a message when it starts/stops.
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Quite agree Howard.
I do know some fiats do have a dash light when a regen is running.
Another thing I've noticed during a regen if I lift off the throttle the exhaust makes a strange noise, sounds a little like an exhaust leak, I've noticed it a couple of times before I twigged it.
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Also a record of regens completed/failed on the fuel economy monitor screens wouldn't go amiss.
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Just got back from shopping 3 mile away, DPF was cleaning just as I pulled into the garage, but I couldn't be bothered to waste fuel driving round just to finish it.
Along with a dash indicator, a start DPF burn button would be useful, especially during a long trip.
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So what are the implications of stopping a regen mid cycle?
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Diesel in the oil.
Last car raised by around 8mm above full before service. The oil used is designed to cope with some dilution, so I don't worry about it.
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Car manufacturers don't want the owner knowing that a regen is taking place. It's supposed to be automatic and a lot of owners would worry about it. I'm not keen on leaving mine part way through with the fans running and it smelling of burning or the thought of possible dilution.
It's a legacy of running a modern diesel.
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A very interesting article posted a little earlier by Willpower that I shall have to read through a few more times. That said, para 3 raised an eyebrow especially as my own CX-5 shall shortly be called into duty pulling our caravan. On a 'typical' motorway run I'm pulling around 2,000rpm at the 120km/h mark with the Auto box of course now in 6th gear. There's absolutely no way these conditions are going to be met when pulling a caravan and I'm now beginning what impact this will have on DPF regeneration.
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I've had enough of DPF cars.
Yesterday i was driving home from a days fishing a 15 mile trip with 42 mpg on the inaccurate average read out, only to detect the exhaust bubbling noise on the overrun telling me yet another DPF clean was on going.
Read out which shows around 2.5 mpg high was down to 36 mpg, i can get around that with a petrol car, so my next car will probably be a turbo petrol.
Towing i got 25mpg and 27mpg, less the 2.5 mpg error, so really not impressive, i got much more with the manual car
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I know exactly what you mean. I set the trip meter on the CX3 and it seemed to regen close to every 200 miles regardless of duty cycle. It would be helpful if they would give some indication and you could suspend or induce it as mine always seems to coincide with short trips rather than my mixed duty 23 mile journey to work.
It seems odd that every other country in the world have the option of the 2.5 petrol AWD auto. We don't???
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I'm given to believe that this is taken from the Mazda training manual.
(http://i724.photobucket.com/albums/ww248/Alan_Ingham/Mazda%20CX-5/Emission%20System_zpsgzlbxr7i.jpg) (http://s724.photobucket.com/user/Alan_Ingham/media/Mazda%20CX-5/Emission%20System_zpsgzlbxr7i.jpg.html)
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It seems odd that every other country in the world have the option of the 2.5 petrol AWD auto. We don't???
I suspect that some of that is down to company car tax being based on a % of vehicle value, with % determined by CO2 emissions. That makes the 2.2 Diesel very tax efficient (the 150 and 175 versions have the same CO2 figure ???), probably the best in its class, and one of the main reasons why I'm on my second one (as a company car).
Alan
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I can only recall two occasions in 70K miles where I remember a DPF regen on by first CX5 and I've not seen one as yet on by second (currently 15K miles). I assume that they must be happening? However, I do tend to do at least one long round trip per week of at least 150 miles, so they must be happening at motorway speed in which case you'd not notice anyway?
Alan
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I can only recall two occasions in 70K miles where I remember a DPF regen on by first CX5 and I've not seen one as yet on by second (currently 15K miles). I assume that they must be happening? However, I do tend to do at least one long round trip per week of at least 150 miles, so they must be happening at motorway speed in which case you'd not notice anyway?
Alan
Motorway running is probably the best for the engine and quite right, you won't notice the regens. They might be cheaper for CCT but mine is in private ownership and I would put up with the lower fuel efficiency of a petrol.
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Why can't we have a DPF regen warning on the display?
Actually, there is a quite reliable way, discovered today. If you know that roughly every 250 miles you have a regen, just display the App -> iStop and when regen happens the engine icon is not longer blue and the iStop become "NOT READY" for the whole length of the process, also the average mpg consumption on that page displays "--.--". When after 7-10 minutes the regen has completed, the engine icon returns blue and the iStop becomes "READY". I now have reset the Trip A so I will keep an eye from now on.
After my first service (13k miles) the oil level was just above the max, however now after just 3k miles the oil level has risen of about 8 mm above the max, that means I had many interrupted DPF regens.
With this tip I should hopefully be able to make sure to never interrupt DPF regens. Also, after my first service my drive habits have changed, I still drive 50 miles a day, but no longer on the M4 so it is now somehow more difficult to reach and maintain the right condition for the DPF regen and minimise interruption.
Eddy
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Why can't we have a DPF regen warning on the display?
Actually, there is a quite reliable way, discovered today. If you know that roughly every 250 miles you have a regen, just display the App -> iStop and when regen happens the engine icon is not longer blue and the iStop become "NOT READY" for the whole length of the process, also the average mpg consumption on that page displays "--.--". When after 7-10 minutes the regen has completed, the engine icon returns blue and the iStop becomes "READY". I now have reset the Trip A so I will keep an eye from now on.
After my first service (13k miles) the oil level was just above the max, however now after just 3k miles the oil level has risen of about 8 mm above the max, that means I had many interrupted DPF regens.
With this tip I should hopefully be able to make sure to never interrupt DPF regens. Also, after my first service my drive habits have changed, I still drive 50 miles a day, but no longer on the M4 so it is now somehow more difficult to reach and maintain the right condition for the DPF regen and minimise interruption.
Eddy
Is this the later KF model. Did you check your oil immediately after it was serviced?
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Is this the later KF model.
It's the 2016 model being built in February 2017. I bought the car in June 2017.
Did you check your oil immediately after it was serviced?
Unfortunately I didn't. I know, my bad, I should have really. I don't know whether the oil level was above the max already (unlikely knowing the dealer; when I bought the car last year, the tank had only 30 miles worth of diesel and the dealer had the very embarrassing excuse that their fuel pump did broke the day before, appalling as I bought the car in cash!)
I need to keep an eye on the oil level weekly of course, bit with the iStop application page I can finally keep an eye on it.
The oil is definitively very dark and smell of diesel a little bit, but I don't really fancy pumping out the oil via the dipstick and top up. I've managed to replace the oil as Mazda recommend after 12.5k miles before, hopefully I should be able to do again ;)
I'm glad you replied as I found your posts always very interesting and knowledgeable. I've read somewhere in this forum that you always put a can of BGxxx after 10k miles, is that really make a difference? I filled her with Shell vPower since day one and stick with it. Do you reckon the additives in the diesel are not enough to keep everything clean? Thanks for your advice.
Eddy
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OK, that’s interesting because somebody I was talking to reckoned his 2016 didn’t dilute his oil but that’s another story!
You can get in a proper mess with this oil dilution without the dealer helping. It should have 5.1 litres of oil added which usually brings it to about 5-6mm below the full mark. It should also have the oil data reset or it will start throwing warning lights up. It’s up to you what you do now. You could tell the dealer and let him sort it out or continue to run and see how far you get. If you are mechanically minded, you could do your own oil changes and reset your own oil data.
Regarding fuel additives, a can of BG244 once a year won’t harm even using V Power but that fuel is heavily loaded with detergent so you are already doing good.
Keep your chin up. It’s all part of running modern diesel engined cars.
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Just out of interest - because it makes a massive difference to the re-gen cycle - what version of the car's firmware are you lads on? Mazda finally fixed the re-gen issue with firmware EU 59.00.502. If you're on an earlier version then you'll continue to have the issues you describe.
The very latest firmware version is EU 59.00.532 but really, as long as you're on EU 59.00.502 (or the latest EU 59.00.532), you will see an end to these bloody re-gen, oil contamination issues. Your dealer should install either of these firmware versions - preferably the latter obviously.
Let me know if you need more info.
Cheers
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Just out of interest - because it makes a massive difference to the re-gen cycle - what version of the car's firmware are you lads on? Mazda finally fixed the re-gen issue with firmware EU 59.00.502. If you're on an earlier version then you'll continue to have the issues you describe.
The very latest firmware version is EU 59.00.532 but really, as long as you're on EU 59.00.502 (or the latest EU 59.00.532), you will see an end to these bloody re-gen, oil contamination issues. Your dealer should install either of these firmware versions - preferably the latter obviously.
Let me know if you need more info.
Cheers
I'm on the EU 59.00.502, the dealer did the update in April 2018 as part of the first 12.5K miles service, however I can still see oil dilution, unless the dealer did put more oil than required (unlikely).
I will keep an eye on the oil level in the upcoming weeks and also using the iStop application page to make sure I never interrupt one.
Could you please elaborate more on how Mazda could have fixed the oil dilution issue with a firmware update? If I understood properly the oil dilution is a side effect of interrupting the regen by means of switching the car off, so unless the new firmware update is actually preventing the car from switching off during the regen I don't understand how that could be achieved? Again, this is from my understanding of the whole process and, of course, I could be totally wrong and interested to see comments from experts.
Eddy
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Firstly, that firmware update is for the audio system. It has nothing to do with the engine.
In addition, let me assure you that dilution is not just a function of interrupted regens. My 2016 had good long runs that got right up to temperature. I knew they were happening by the exhaust note and the loss of Istop but it still diluted at an alarming rate. There may well be software patches that will address some of the dilution but you need to speak to the dealer.
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OK, that’s interesting because somebody I was talking to reckoned his 2016 didn’t dilute his oil but that’s another story!
You can get in a proper mess with this oil dilution without the dealer helping. It should have 5.1 litres of oil added which usually brings it to about 5-6mm below the full mark. It should also have the oil data reset or it will start throwing warning lights up. It’s up to you what you do now. You could tell the dealer and let him sort it out or continue to run and see how far you get. If you are mechanically minded, you could do your own oil changes and reset your own oil data.
Regarding fuel additives, a can of BG244 once a year won’t harm even using V Power but that fuel is heavily loaded with detergent so you are already doing good.
Keep your chin up. It’s all part of running modern diesel engined cars.
Hi, just wondering if you actually do your own oil changes. If so, what oil do you use? Looking at doing interim oil change my self if and when needed.
Many thanks in advance.