Diesel in Engine Oil

Faults and Technical chat for the Mazda CX-3
mimiaris
Posts: 6
Joined: Tue Apr 02, 2019 8:56 pm
Location: Croatia

Post by mimiaris »

Hi, I am Marko from Croatia. Please if you can send the dpf regeneration process from the fuse box .My email adress: markod1980@gmail.com

bogdanandronesterca
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Joined: Tue May 07, 2019 7:20 am

Post by bogdanandronesterca »

Bought a used 2016 CX 3 1.5 diesel, 3 weeks ago with 107000km on the clock. Noticed that the oil was high to the X mark on the dipstick. On oil change I measured the oil that I took out and it was around 6.3 Liters(including the oil that i took out of the filter, more than 1 liter to much), and according to the label on the engine, last oil change was 8000 km ago. I think the car is doing a lot of silent DPF regeneration around 3 times a week since I-Stop not working and fan continue running after engine stop (no warning signs in the dash or in the main screen). Tomorrow it is scheduled for service diagnostic. Guess I will be needing new injectors and like people mentioned here before it is no guaranty problem will not come back. I am surprised that no factory recalls have been made for this problem. Expected more from a car that is less than 3 y old, good job Mazda... Will let you know more after the trip to the service.
bogdanandronesterca
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Post by bogdanandronesterca »

The official Mazda Dealer did a full diagnostic on the car and said it is in great condition and has no errors. Told them about the oil going up on the dip stick and they said that the dilution is a common thing with the diesel engines which are not suited for short trips and I should monitor it and change the oil if it gets to the x mark, and "under no circumstances should be the car driven after the oil gets to the x mark which can lead to engine damage". They printed out a full Data Service Record of the car mentioned it had been recalled 2 times, one time for the pistons that hold up the tailgate and one time for the software update that was related oil dilution (update for injectors function, DPF regen, and others). Glad the the owner before me did the service on time...Still think that the diesel getting into the oil in such large amounts when the silent regeneration is interrupted, is caused by a pour engine design by mazda. Will monitor the level of the oil and let you know how it goes. Until now I did 700 km with the new oil and the mark it is ok on the dipstick. Dealer suggested filling the oil to the minimum mark on the next oil change, to prolong the overfilling from dilution.
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AndyRen
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Post by AndyRen »

I can't really help you, but fuel in the engine oil is a problem with all newer diesel engines with dpf's not just Mazda! Short trips are a major problem with the resultant failed regen's when the engine is switched off before the regen has finished.
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bogdanandronesterca
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Joined: Tue May 07, 2019 7:20 am

Post by bogdanandronesterca »

I have been monitoring when the car is doing the silent regeneration, so I don't interrupt the process and the oil has not been rising since. Does anyone know how I can speed up the silent regeneration process. Or maybe is it time based and it will stop after a period of time regardless of how many km you have done or how many revs/ speed you are driving at, since the start of the regeneration? On my last silent regen, after the process started, I drove around 7 min at city speed avg 35-40 km/h then I got to the parking lot and and accelerated with the car in neutral every few seconds. Did this for 10 minutes and still did not finish, so I figured maybe the wheels have to be moving... I moved the car 40 meters and the regen process was completed. Was it a coincidence that it ended when I moved the car? Did anyone managed to see the silent regeneration complete while the car is not moving but the engine was on?
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AndyRen
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Post by AndyRen »

I may be wrong but I think it's a bit more complicated than that, there are sensors covering all manner of engine/exhaust/DPF soot levels etc that may vary on a day to day basis dependent on engine temp, external air temp etc etc, so I don't think you'll ever get a proper result??

As I say, I may well be wrong? But when you notice the car doing a re-gen then continue to drive it for a while (time and speed I couldn't say though).
16 plate 2L Petrol, 120bhp Soul Red Sport Nav...
bogdanandronesterca
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Joined: Tue May 07, 2019 7:20 am

Post by bogdanandronesterca »

I noticed that I get better distances between DPF regenerations and less oil level rise after I changed my oil to Ravenol VMP USVO 5w30 and replaced the dpf differential pressure sensor, it did not happened straight away it took a while until I noticed the difference. Distance between regenerations have gone from 60km when driving outside city to 120-140 and from 50km or less in the city to 70-80km. It is not ideal but the biggest improvement so far. Managed to do 7000km so far with this oil change and the level went from just above the low mark (hole) on the dipstick (when the oil change was performed) to just at the high mark (hole, not the x at the top). Will continue to use the same oil for the next oil change, hope things will keep improving, or at least won't get worse :).
I want to mention that before the changes mentioned above I have tried the oil Mazda Original Oil Ultra DPF 5W-30 (which had made the matters worse), performed the DPF Regeneration wihile the car was stationary with the engine running (triggered with diagnostic tool), performed the injector calibration via diagnostic tool, and none had any noticeable effect.
PAVLOS
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Joined: Tue Sep 29, 2020 8:30 pm

Post by PAVLOS »

Hi from Greece and thanks for accepting my register
i am an owner of CX3 1.5 DIESEL AWD with about 45.000 km. (my 2016)
Yesterday while i was parking the flashing DPF apears.After that i went in local mazda service .They checked it and the first think is that they found diesel in engine oil .They tried several times to regen DPF and they didn't managed at all .After all they told me that the possible cause of that is faulty injectors and must be replace them.I am very suspicius about that conclusion and i will be really greatfull if you share your opinions about that. (the car works very smoothly until now with no problem at all no knocks from injectors,with full throttle,...as a normal car)

thanks in advance
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AndyRen
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Location: Down a bit, down a bit more, right a bit, down a bit.... Right there - Kent

Post by AndyRen »

Faulty injectors could possibly be the case, it their seals are leaking it could allow fuel into the oil....

https://www.injectorrx.com/fuel-injecto ... injectors/
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mr_chris79
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Joined: Wed Jun 30, 2021 12:29 am

Post by mr_chris79 »

anchorman wrote: Fri Jan 19, 2018 1:21 pm You can actually force a regen on a CX-3 without turning a wheel. It will run through a variety of engine speeds for set periods of time all on its own.
Is it possible for me to get the pdf please? I have performed a regen using forscan and reste the oils dilution data straight after I changed the oil but your comment about varying engine rpms has me wondering if the forced regen instigated by forscan wasn't enough.
2016 CX3 1.5td
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