As a new diesel vehicle owner I have been taking some time to look at the regen process. I understand the principles but have never looked at the detail. I researched this mainly because I do have periods where I only run short journeys at rural road speeds and wanted to understand what the risks are and what the warnings, if they ever appear, might be telling me.

 

Looking at the tech blurb on the EA288 engine http://www.briskoda.net/forums/topic/372793-self-study-guide-for-ea288-diesel-engine/?hl=%2Bgeek#entry4389658

 

I found some of the detail I was looking for. It identifies 5 types of regen which are reasonably self explanatory:

• Passive regeneration.

• Heat-up phase.

• Active regeneration.

• Regeneration trip by customer

• Service regeneration

 

I was also looking for some info on what information I would get about the failure of regen cycles and impending dpf issues. There is no warning that a regen has failed. However, the first warning light comes at a load of 30 grams at which point you obviously need to do a customer regen trip. The final ‘get to a garage quickly’ comes on at 40 grams hopefully allowing the car to have a service regen before the filter is NFU. (45 grams load)

 

The other interesting things that I found were:

1. “Mileage regeneration” is used as an additional safety system to keep the load condition of the diesel particulate filter low.
2. The ECM automatically initiates an active regeneration if there has been no regeneration, or no successful regeneration, in the last 465 miles, regardless of the load condition of the diesel particulate filter.
3.  “The charge pressure is adapted so that during regeneration torque does not change noticeably for the driver.”

 

First question. Is this new tech for Skoda coming with the EA288 engine or is it all pretty much basic stuff used on older engines?

 

Second question. Is it necessary for the car to be driven in a steady state for a given period to achieve a regen once it is triggered?

 

Third Question. Can I tell when it is in regen phase if as Skoda claim the torque will not change noticeably? I guess a drop in mpg might be apparent?

 

Over to all you diesel gurus out there.

 

thanks in advance

First question:

No, this is not anything new - it works like this in my EA189 as well. Car actually feels slightly more powerfull when doing a regen due to charge pressure being regulated

 

Second question:

I read somewhere, that the new generation is not that sensitive to the driving method. "Older" units such as my EA189 CAYC likes around 2500 rpm when doing a regen.

 

Third question:

On my car, I can tell a regen is ongoing by:

 

RPM at idle raised to 1000 (it does this when starting up below 0 degrees as well to heat up)

A smell of burned diesel

Start/stop unavailable.

KM/L on MFD drops slightly when driving

Just drive the car normally when it's regenerating. More often than not, you probably won't notice when it happening. 

 

I find my car regenerates every 350 miles or so, sometimes it'll be lower if i've been sitting in the **** London traffic. 

 

From personal experience and over 150,000 miles of DPF diesels:

(Apologies for going over some of the things mentioned above)

 

The oil temperature will be slightly higher than normal, usually 99-103ºC on average. 

 

The idle RPM will be slightly higher than usual (just a shade under 1000 rpm)

 

The engine may feel a little 'lumpy' at part throttle, this is due to post injection taking place to raise the exhaust gas temperatures to around 550-600ºC for regen.

 

You may hear the exhaust note become a little 'boomy' at certain rpm. Mine is like that at around 2200-2500rpm, at part throttle. 

 

The cooling fans may continue to run at full speed for a few minutes when turning off the engine during regen. This is to dissipate the build up of heat in the engine bay. (There is no problem interrupting a regen BTW, it will simply resume on the next journey, once the engine is up to temperature).

 

There will be a hot/burning smell for the first few thousand miles. This is just the various coatings, release agents and excess sealants burning off with the increased heat. This is normal and will pass. Ever followed a car with a brand new exhaust on it? That.......

 

Occasionally, there may be the odd puff of white from the exhaust. This is the incinerated soot being kicked out the back and is normal. 

 

Some of the above may vary slightly as my experience is based on 2 CFGB CR170 engines, but I am guessing there won't be much difference. 

 

And the final rule: forget about the DPF and just enjoy the car. As long as there are no warning lights on the dash, there is nothing to worry about. 

+1 on all the above

Exactly what dstev2000 posted. BUT...if the DPF light comes on, do NOT ignore it!

Thanks everyone for the prompt responses :clap:

 (There is no problem interrupting a regen BTW, it will simply resume on the next journey, once the engine is up to temperature).

That's especially good to know thank you. I couldnt imagine that it wouldnt given the process but confirmation is nonetheless welcome.