DPF Regen issues

[Notoriousdhb]

Hi, sorry for posting a new topic as I am sure there is a topic somewhere within this site - just new to the site at the moment.

I purchased a 68 plate CX-5 2.2 150bhp manual on 1.9.2018. having done only 4600 miles, I needed an oil change much to my disappointment due to diesel contamination. My regular journey to and from work comprises of 50/60 mph driving up A roads and I do two 100 mile motorway journeys per month.

The problem for me was not not knowing when the regen was happening and how often it happens. I have read various comments on the internet suggesting 250/300 miles - can anyone confirm please?

Friday gone, I noticed for the first time my car conducting a regen, however, I had to stop at red lights. Indications were that it was still doing the regen and this continued for an additional 2 minutes once the lights went green. I'm hopeful all went well - just can't be sure.

I have also got a theory which I would like to put out their. On the IStop monitor, three conditions have to be met for the IStop function to work (Engine, Air Con, Battery). My understanding if one or all of these are not met then the IStop function will not work. Also, my understanding is that when the car is doing a regen, the IStop will not work. Based on this, can I monitor when the car is conducting a regen based on the blue glow for the engine going out along with an increased MPG.

I only ask, as I have not noticed any of the other indications such as loud fans or white smoke etc.

Many thanks for your time and hoping to hear some positive feedback. Negative also welcome of it comes with a positive spin on it.

[ROCKETRON]

I thought all this dilution was all sorted now on the later cars like yours. I have an old 13 reg cx5 and get very little dilution but I always try to finish a regen and will often drive further than needed just to finish the regen. Regens on my car seem to be around 280-400 miles. Also I only use the car for long journeys so I am sure that helps. It is true that I stop doesn’t work when doing a regen but there are lots of other reasons why it doesn’t come on particularly at this time of the year so wouldn’t be a good way of spotting a regen. I find keeping an eye on av mpg the best way of being aware of regens..

[Notoriousdhb]

Hi and thanks for the reply. In response to you saying you thought the problems were now sorted on the newer models. The garage I bought it from are a bit in agreement with that as they said it should not be happening and can't understand why - it did not help that I had to go to a different Mazda dealer to get the oil changed due to proximity etc. They said it looks like my car needs a software update but they are not sure when it will be released (this is a bit confusing to me because if the problems should not be happening, how do they know it needs a software update that does not exist yet). The confusing part is the garage which undertook the oil change said it was perfectly normal for this to happen at 4600 miles/4.5 months old. I disagree as I should not have to undergo 3 oil changes per year. Discussions have taken place between both garages and it now appears that I may experience this again in the next 4600 miles. It was then hinted that it may be my driving style.

My driving style consists of a mixture of 40/50/60 mph to and from work which is about 17 miles each way. I also do two one hundred motorway drivings over the weekends per
 Month. Whilst I agree that I am not a heavy mileage driver, on purchasing the car, I was informed that the petrol version I wanted would not really be suitable and my driving behaviour is best suited to the version I now own. I feel the sales team say one thing whilst the tech team contradict. They all should be singing of the same sheet tbh.

I suppose all I can do is monitor the Regens and do regular oil checks. I was hoping the Regens would be of a regular intervals so I could at least predict it happening and ensure I could time it on a route on the motorway etc. As far as Regens go, I take it they are only passive?

Also, when my car was performing a regen and then I had to stop at a red light, would this cause a regen failure? Or would it have successful because when the lights turned green the mpg was very low and the blue engine glow was out for about 2 minutes. Just don't know if I must drive at a set speed and with high revs (2200) to complete regen or if this can happen if I am in a 30 zone etc.

Sorry for all the Q's, just trying to be proactive in preventing undue problems.

[Bert321]

I have also got a theory which I would like to put out their. On the IStop monitor, three conditions have to be met for the IStop function to work (Engine, Air Con, Battery). My understanding if one or all of these are not met then the IStop function will not work. Also, my understanding is that when the car is doing a regen, the IStop will not work. Based on this, can I monitor when the car is conducting a regen based on the blue glow for the engine going out along with an increased MPG.

Yes you can monitor whether the car is doing a regen by the lack of glow around the engine icon.  The glow also won't be there if the engine is cold tho.

FWIW My previous 64 plate and my current 17 plate do a regen every 170-200 miles.  They last maybe 7 miles at motorway speeds.  I try to keep the revs above 2k to help it along.

[ROCKETRON]

As far as Regens go, I take it they are only passive?


The regens in a cx5 are only active, ie they inject diesel into the exhaust stroke to heat up dpf to high temperature. A passive regen is a regen that is done by driving the car hard(full throttle on steep hill e.g) and getting the dpf hot enough to burn ff particulate matter. Not sure the cx5 does passive regens as active regens are done at set intervals.

[Notoriousdhb]

Sorry, got the active, passive bit wrong way round but you have confirmed what I thought in that they are timed intervals as i did try to force a regen on motorway but no regen took place.

[kiakid2]

I can only manage 6500 mile between oil change warning illuminations - which is a bit disappointing when the service interval @12000 miles cannot be achieved. Fortunately for me I am only doing 7000 miles per year.
Strange though - I have never been aware of any regeneration taking place! 

[Willpower]

> kiakid2     Could you sort out your fuelly entries please. One is sufficient and they don't match anyway.   Thanks   

[ROCKETRON]

> kiakid2     Could you sort out your fuelly entries please. One is sufficient and they don't match anyway.   Thanks 

As your fully consumption is only 39mpg for a manual car I assume that you are mainly doing short traffic town centre type driving. During this type of driving it is harder to detect a regen using the av mpg method. When you are cruising on motorway the av mpg stays fairly constant, but drops a bit if speed goes up and goes up a bit when av speed is slower, when a regen starts that av figure drops noticeably when you were not expecting it to. During high traffic town centre type driving the figures go up and down a lot anyway depending on t/lights acceleration etc.so it’s harder to recognise a drop caused by regen.

[Jonno21]

On my June 2018 built CX5, bought mid October 2018, I've done approx 3,300 miles and the oil level hasn't budged. According to Fuelly my average mpg is 43.4mpg. My previous 2016 CX5 averaged 40.0mpg and the oil level did rise a couple of mm over the max mark it was well below the X mark with no warning lights with oil changes at the annual interval. I average 11,500 miles per year. Notorious, I suggest there is something wrong with your car.

[Notoriousdhb]

Hi everyone and thanks for the feedback given. I have today just noticed the car doing another regen which is 200 miles since the last one. I have now got a base line to work with as I now anticipate another regen in 200 miles. Trip computer reset to enable easy monitoring.

@jonno21. You may well be correct as the garage initial thoughts was that this is not correct given the age of my car and did say I may require a software update when it comes out. However, I am now keeping a close eye on everything now. To be honest, as I have been unaware of when previous Regens have been taking place, I could have been turning the engine off mid-way but can't be sure. Also, based on my mileage and the car doing a regen @ 200 miles (only based on previous two admittedly), that equates to 5 Regens a month that may not have completed. I am keeping an open mind on it and hoping things will stay trouble free until service on Sept 19. I am also going to do weekly oil checks as a precaution. If the problems persist, then I would for sure say the car is at fault. If the issues stop between now and Sept19 then I will accept it may be down to my driving style and not (foolishly) knowing when previous Regens have occurred.

Once again, thank you for your feedback and input on personal experiences. I hoping to be in a position to post a positive update in the months to come that may offer some reassurances to new cx5 owners.

[Anchorman]

On my June 2018 built CX5, bought mid October 2018, I've done approx 3,300 miles and the oil level hasn't budged. According to Fuelly my average mpg is 43.4mpg. My previous 2016 CX5 averaged 40.0mpg and the oil level did rise a couple of mm over the max mark it was well below the X mark with no warning lights with oil changes at the annual interval. I average 11,500 miles per year. Notorious, I suggest there is something wrong with your car.

Jonno, is yours the Adblue version?

[Notoriousdhb]

Hi Anchorman, I know the Q was not directed at me but I thought the adblue only came out on the models released 01.09.2018. I think this is why the diesel models only have the one exhaust whereas previous non adblue had the two exhausts.

[Jonno21]

On my June 2018 built CX5, bought mid October 2018, I've done approx 3,300 miles and the oil level hasn't budged. According to Fuelly my average mpg is 43.4mpg. My previous 2016 CX5 averaged 40.0mpg and the oil level did rise a couple of mm over the max mark it was well below the X mark with no warning lights with oil changes at the annual interval. I average 11,500 miles per year. Notorious, I suggest there is something wrong with your car.

Jonno, is yours the Adblue version?

Hi Anchorman - Yes, It's the Adblue version. Notorious - I have only one exhaust pipe.

[Anchorman]

Collected my GT today. Single exhaust and I shall be watching my oil carefully!