Mazda CX-5 2.2 SkyActiv-D - DPF filling fast

[spektr]

Injector washers
DPF cleaning

[hiej]

I have had same problem on 2010 Mazda3 for almost one year.

different engine, not the Skyactive (it is the R2 2.2d with 185 HP) but same behaviour:

- frequent regenerations specially if pushing hard the engine ( one evey 150/200 kilometers instead of 450/480)
- PM-ACC and PM-DSD growing fast and sometimes suddenly
- regenerations triggered when PM-ACC reached 6 g/l instead to be triggered by PM-GEN = to 6 g/l
- no errors on PCM

I've tried everything:
- cleaned EGR, EGR cooler end related pipes
- cleanend the intake manifold
- cleaned injectors
- used various kinds of DPF cleaners
- changed injectors washers
- done every kind of EGR/ITB, injectors and sensor calibrations
- done DPF resets, assessment, forced regenerations...

but no improvements

at the end, I've changed the EGR electronic part (the motor) and everything is fixed now: even if the engine have more than 240.000 kilometers regenerations starts again every 450/480 kilometers.
PM_GEN reaches 6.0 g/l and PM-ACC and PM-GEN grows slowly and not randomly like before.

I know Skyactive have 2 EGR valves, maybe the issue is in one of their actuator motors.

[spektr]

Nice, thx for sharing your experience!

[skyx]

This is a pretty interesting discussion and I would like to leave my findings.

I work at a Mazda dealership mainly as a diagnostic tech. We had many trouble with one Skyactiv D 2.2. The car had 40k km on the odo. The vehicle is doing regens every ~50KM. It had the latest PCM calibration done, injectors tested out to be okay, differential pressure sensor also okay. Everything has been double checked. All PCM parameters have been reset, injection quantitiy learning done, but no avail.

It seems that whatever is done to this vehicle it does clog the dpf up fast, and in 5500-6000km we get the oil level diluted almost to the X mark.

What I have found out is that they usually do pretty frequent regens, about 200-250KMs, where as some BMW with N57 will do them as much as 750-800km.

Also, we don't get any support for this from Mazda, the main thing they always talk about is short trips, which other cars with DPFs will do just fine without any problems.

It seems that these Denso ECUs don't really have the best strategies for doing active regens, even since the old RF and R2 engines oil dilution is a problem, whereas I don't really remember anyone having oil dilution problems with other vehicle brands.

We also have a couple of vehicles with revised SH engines (without IDEVA, increased compression ratio and revised 4pin injectors) doing regens from 240 to 400km, but still diluting the oil to the X mark in as little as 6000km. A PCM calibration is said to be released for this fixing this problem, but I doubt they will fix it.


I have one possible theory. We found 2.2 Skyactiv Ds as little as 50000km to experience P0401 insuf. flow faults. This always results in the intake manifold being clogged in such a way that I have never seen before in even big mileage diesels. My finding here is that these engine management systems hugely rely on EGR to reduce NOx, because Skyactiv was developed not to have any aftertreatment systems (AdBlue) but still conform to Euro 6 emissions. In this way utilizing the EGR too much, soot is created clogging up the DPF very fast, requiring frequent regens.

The new revised 2.2 SH with AdBlue should have fixed this problem, that is why I have seen them with 400KM regens.

And for the end: clean diesel is a big lie, all of this crap is just "bodged" to conform to emissions but longevity is not looked for. Besides why would you have a D when you have a masterpiece like the Skyactiv G and X?

[spektr]

Nice post man. Well i bought a D mainly because towing a trailer. Otherwise, i think i woul go for g192 at that time, now maybe for g194. But unofortunate, in Europe this G engine comes without turbo, which is a pitty. I would instantly buy such engine...

About D and intake manifold. Is there anything to prevent this? When you see the regen is too frequent, one option is to take this apart and do a special cleaning. There is a special sensor which could also be clogged i guess.

[skyx]

Nice post man. Well i bought a D mainly because towing a trailer. Otherwise, i think i woul go for g192 at that time, now maybe for g194. But unofortunate, in Europe this G engine comes without turbo, which is a pitty. I would instantly buy such engine...

About D and intake manifold. Is there anything to prevent this? When you see the regen is too frequent, one option is to take this apart and do a special cleaning. There is a special sensor which could also be clogged i guess.

Yes, you are right about the G.

It seems like the worst case of clogging was on a vehicle that is only driven in the city with traffic and short trips.

I don't think you can prevent this from happening apart from not doing short and slow trips.

I think that cleaning should be done at about 100-120k km. The MAP sensor is located on the intake manifold and it will be full of carbon. I will provide some pictures when I get the time.

[spektr]

Thanks, for your input. Well, i am watching those DPF parameters for a while now, and last time i saw that it really needs some hard driving on a highway. After that PM_ACC_DSD value goes down significaly. As for my knowledge this is the PID everyone should watch in case something strange is going on with the whole regeneration ..DPF stuff.

And of course, the injector washers are still the key problem. I will change them next service at around 80k kilometers, just to be sure. This is really cheap to prevent a catastrophy.

[skyx]

Thanks, for your input. Well, i am watching those DPF parameters for a while now, and last time i saw that it really needs some hard driving on a highway. After that PM_ACC_DSD value goes down significaly. As for my knowledge this is the PID everyone should watch in case something strange is going on with the whole regeneration ..DPF stuff.

And of course, the injector washers are still the key problem. I will change them next service at around 80k kilometers, just to be sure. This is really cheap to prevent a catastrophy.

Of course the injector washers are the biggest problem. It also doesn't hurt to check oil pressure every now and then (EOP PID at least 3.1bar on 4000rpm). Also we very commonly had the oil pump chain snapping, mostly on earlier 2.2D from 2013-2015, we never had the exact year when they started using the revised chain. The redesigned chain has 5 yellow links whereas the old has 3.

I had a 2.2 Skyactiv D grenade itself just 100 meters away from our workshop when I went on a test drive, #4 conrod went through the engine block. We never disassembled this as the customer just towed the vehicle away. This engine can be pretty reliable when looked after, but they mostly are not.

[skyx]

This is the extreme case of intake manifold clogging I talked about. Only about 50k km on the odo. This condition almost always triggers a P0401 or P0101 DTC.

I think that there's a huge story behind the SH engine.

[spektr]

OMG, that must be some extreme city driving that diesel wasn't made for...omg