[UtkarshC]

Thanks to Rakesh Balasubramanya for sending this information in. Heartfelt gratitude for sharing it with other enthusiasts via this Team-BHP share page!

Hi Team-BHP,

Good Day!!!

I am writing this email as you are already aware of many people facing problems with BS6 diesel engines regarding the REGEN/DPF issue.

I bought a Mahindra Marazzo M6+ on Jan 30th 2021 and so far I have faced REGEN/DPF issues 16 times and very frequently. Please find the details below.







Seriously, it has become harassment to me. Now, on the 2nd of October, a breakdown happened when I was travelling with my family on NICE road Bangalore.

After inspecting for 4 days, they have sent me an email as below.



I have asked them for a replacement and they are least bothered about it and are telling me that they can only replace the engine and not provide a replacement for the vehicle or make a refund.

As per the BS6 norms, vehicles should not be driven in certain conditions to avoid REGN/DPF issue. Following is M&M’s reply to the question, “when does REGEN/DPF problem can occur?”

"As explained to you several times, DPF / REGEN process is common in all BS6 diesel vehicles. If the vehicle continues to be driven at any of the following conditions, the accumulated soot may not be automatically removed because of low exhaust temperature.

• Heavy traffic driving conditions, especially in the city
• Frequent short trips
• Low speed for a long time"

[Bibendum90949]

With frequent DPF choking, I guess below is the reason for engine damage. The excess oil they talk about is the soot reaching oil sump I reckon.

Originally Posted by Bibendum90949

I gather that driving long enough with a clogged DPF is detrimental to its life besides loss of power and can even create back pressure to the engine that can cause engine damage or even soot getting to the oil sump through the combustion chamber.

[PrideRed]

BS6 for sure is complex and not trouble free as BS4. Irrespective of manufacturer one needs to handle these cars carefully. Few things to consider(Mostly based on my personal experience)

1. BS6 diesel donot like city traffic. If you are buying BS6 diesel and just use in peak traffic 90% of time, its an overkill.
2. In highways too, one needs drive at varying speeds. Driving at constant speed especially anything less than 70-80, you are inviting more regens and possible trouble.
3.Quality of fuel is extremely important. If you are doubtful of a station, please avoid.
4. I guess outside temperature and altitude will also have an impact. Lower temperatures and higher altitude will make regen difficult.
5.You need to rev up engine once per drive, from my personal experience, this helps.
6. Keep a watch on AdBlue if that's applicable to your car.

I am sure there are lot of users who buy car without knowledge of BS6, some even don't know there is DPF and car needs AdBlue. If expectation is fill it shut it forget it, one needs to cautious, have some basic understanding and a use case.

[lsjey]

No wonder, the demand for diesel vehicles have come down drastically. I think BS6 will effectively kill diesel engines altogether. I used to like the torque of Vista and Manza a lot. I still love the diesels and miss them, even though I like the Honda City ivtech engine.

This is really sad. I think there have been enough instances of DPF issues for affected people to band together and file a class action suit. Only then manufacturers will sit up and notice.

Regards,
lsjey

[Kosfactor]

Gentlemen our humble BHPian found the solution to DPF problems sometime ago.

Originally Posted by GTO

If your DPF is getting blocked primarily because of short-commute city driving, it only means one thing = GET A LIFE (sorry, no offence meant ).

- Go for a long drive on the highway .

- If no time for highway, go for a long drive in the city @ higher speeds. E.g. in Mumbai, it could be the Sea Link & Freeway. In Bangalore, it could be the airport road.

- Give the car an Italian tune-up from time to time (sample video below).

After all, as BHPians, we live to drive! So go out, and drive for the pleasure of it. Tell the wife that "my DPF needs it".

https://www.Youtube.com/watch?v=JgJgSxCFv1A

A bad habit among drivers with diesel is short shifting, lugging the engine to extract maximum juice out of the fuel. Diesels need to run, BS4 will clog your Catcon, BS6 will clog that and DPF.

[CarLover79]

It's a double whammy if you are an Indian car buyer at the moment. On one hand, BS6 diesels are having these issues and if you were to choose petrol, the fuel prices are sky high and mileage in larger vehicles is not economical. Add to it, confusing statements on blended petrol being made mandatory.

[gopi_rm]

I see two issues here on the owners’s side:
1. Whenever “DPF fully clogged, connect laptop/take it to service centre…” warning appears, the car must be taken directly to the nearest service centre. It means DPF is clogged beyond self regen limit. One should not try to regen it by driving on the highways.
2. Driving at 60-80 kmph on the highway at top gear might not trigger regen. Irrespective of the speed, engine rpm is the main factor to activate regen. So even if one drives at slow speeds, maintain mid to higher rpm constantly to activate regen. This applies only if the stage 1 warning appears. For stage 2 warning, regen via service tester is mandatory.

DPF is a sensitive and expensive component so handle the warnings carefully. Unfortunately this is the problem with BS6 diesels and such cars are meant for people who uses the car mainly on highways. With BS7, petrol will also get GPF (Gasoline Particulate Filter) and it is already offered by many OEMs due to Euro 6d temp norms here in Europe.

[Kiran Joshi]

Originally Posted by PrideRed

BS6 for sure is complex and not trouble free as BS4. Irrespective of manufacturer one needs to handle these cars carefully. Few things to consider(Mostly based on my personal experience)

1. BS6 diesel donot like city traffic. If you are buying BS6 diesel and just use in peak traffic 90% of time, its an overkill.
2. In highways too, one needs drive at varying speeds. Driving at constant speed especially anything less than 70-80, you are inviting more regens and possible trouble.

I think these are the real life situations where we drive our cars most of the time. OEM must sort of out concerned issues beforehand. Other wise what is the point of purchasing a car (under constant stress of breakdown) and not using it in a way its meant for?

Issues such as DPF and EPC just spoil the end user experience of brand new car. Onus lies upon dealer and OEM to arrive at the solution at the earliest.

Has any one reported DPF issue with Hyundai or Kia cars also?

Regards

[Leoshashi]

Originally Posted by PrideRed

1. BS6 diesel donot like city traffic. If you are buying BS6 diesel and just use in peak traffic 90% of time, its an overkill.
2. In highways too, one needs drive at varying speeds. Driving at constant speed especially anything less than 70-80, you are inviting more regens and possible trouble.

Couldn't agree more. When Dad drives the Crysta, he has seen DPF bars going to 5th level. He likes to cruise and is a gentle driver. I sometimes revv the Crysta diesel too like Petrols and love to accelerate hard. With my driving, it never goes beyond the 3rd bar. High speed I'm not sure, but I believe higher RPMs is what these engines need. Please correct me if I'm wrong.

[Rahul Rao]

The entire commercial vehicle market got over the DPF issue by circulating U tube videos like these, Videos are available in English, Hindi, Tamil, Marathi and Punjabi.

https://www.youtube.com/watch?v=4Xk5zmz_wKE

https://www.youtube.com/watch?v=m3QRtrSdcG0

When semi literate drivers trained themselves within a few months, I cannot understand why literate people cannot follow procedures.
A acquaintance facing DPF issue with his Fortuner was about to call service station, got a shock of his life when a driver whose truck was getting unloaded said DPF is choked, see how to clear it on U tube, and showed his saved video, this person saw procedure on U tube and did accordingly, then said he thought the light was a alternator or some other warning.

Rahul

[anjan_c2007]

I believe BS VI car makers need to prominently display stickers on the front drivers side, displaying precautions and preventive measures to be taken by owners and drivers of such cars.

A maximum percentage of owners do not care to go through the owners manual, nor most are teambhp members or do their search and study here.

Did Maruti sage R. C. Bhargava opt out of the BS VI diesels foreseeing the REGEN/DPF issues?

[PrideRed]

Originally Posted by Kiran Joshi

I think these are the real life situations where we drive our cars most of the time. OEM must sort of out concerned issues beforehand. Other wise what is the point of purchasing a car (under constant stress of breakdown) and not using it in a way its meant for?

Issues such as DPF and EPC just spoil the end user experience of brand new car. Onus lies upon dealer and OEM to arrive at the solution at the earliest.

Has any one reported DPF issue with Hyundai or Kia cars also?

Regards

These are everyday use case but for BS6 to run flawlessly, one has to have some understanding of system and be cautious. I am not saying manufacturers have flawless implementation but if someone ends up idling for hours or gets a poor quality fuel regularly, will be too hard for a manufacturer to work on a solution for a factor which is out of their control. For potential buyers, if you don't have a use case for BS6 diesel, then better to stick with Petrol. The EPC issue seem to be specific to Kushaq and Skoda has some work to do.

Originally Posted by Leoshashi

Couldn't agree more. When Dad drives the Crysta, he has seen DPF bars going to 5th level. He likes to cruise and is a gentle driver. I sometimes revv the Crysta diesel too like Petrols and love to accelerate hard. With my driving, it never goes beyond the 3rd bar. High speed I'm not sure, but I believe higher RPMs is what these engines need. Please correct me if I'm wrong.

Yes Higher RPM, but then many current diesel have low idling and tall gearing. 100KM/Hr comes in at 1500-1700RPM, the engine definitely needs to be hitting more than 2K RPM often. With manual its a bit easier, with auto people don't bother . If you are in Eco mode, upshifts are quick and hardly you will be doing more than 2K RPM. Sport mode, gear limiter should be used liberally. Advantage with Crysta manual is you are doing 2K or more in 5th gear while cruising at 100KM/Hr.

[Kosfactor]

Originally Posted by Kiran Joshi

Has any one reported DPF issue with Hyundai or Kia cars also?

Regards

Yes KIA was the first crossover to offer BS6 diesel IIRC and naturally one of the first to report DPF related errors. You can find it in our forum or click on my earlier post in this thread ^.

[sidg]

It seems only the products from mainstream companies are getting DPF issues. I did not come across any such issues in the Mercedes/BMW. Does it have a different mechanism? or the owners are taking due precautions so that it does not get clogged. I am sure not all the owners of Mercedes/BMW must be driving on highways regularly.

[ashwinprakas]

Among the below requirements;

1. Heavy traffic driving conditions, especially in the city
2. Frequent short trips
3. Low speed for a long time

My Bolero scores a perfect 3/3 and she's at over 5k on the odo and hasn't thrown a tantrum yet.

I live in KL so it's always B2B Driving, trips are obviously short, as for speeds I take my feet of the pedals when I'm in 5th and the idle assist takes over, we'd been to Munnar, Vagamon etc like that, the Highway potency is crap anyhow so at least we make good use of the awesome low end.

Also to add, the Bolero in its short 6 months of life it has stayed idle for the majority of it courtesy my honeymoon, Lockdown and my love for the Alto which has gone up courtesy it being drivable whereas the Bolero is the one driving you.

Having cleared the air my theory is that cars with excessive overdrives are the ones facing the issue cause considering the Bolero the gearing is paced to crawl and hence it is quite common to go over 2k on the tacho even during normal driving and I'm assuming it's DPF gets regenerated as such.

Again my assumption could be wrong and it could be something else that's triggering the frequent DPF issues, feel free to correct me as I'd like to get to know more about this.