[AlanHo]

I went to visit an old friend in hospital this evening - a round trip of 41 miles of which 29 miles are on the motorway and the remainder in town.

I brimmed the car 184 miles (296 km) before I set off and the average trip economy was reading 59.9 mpg (4.72 l/100k) when I started the journey.

I noticed as I cruised the motorway in 6th gear at about 60 mph (97 kph) the average economy steadily falling no matter how gently I caressed the throttle. When I left the motorway I was stopped at some traffic lights and instead of the engine stopping whilst I was stationary the instrument display showed "Auto Stop Deactivated" which I thought a little strange. By the time I reached the hospital the economy trip showed 57.8 mpg (4.89 l/100k) and I began to suspect that the DPF was regenerating and had inhibited the engine auto-off feature.

An hour later I set off for home and had to pass through 2 sets of traffic lights before rejoining the motorway with the economy trip showing 57.4 mpg (4.92 l/100k). Both sets of lights were on red and on both occasions the engine remained running and the instrument display showed "Auto Stop deactivated".  As I cruised the motorway it steadily fell to 56.4 mpg (5.01 l/100k) - hovered there for about 5 minutes - then started to gradually climb until it reached 57.2 mpg (4.94 l/100k) by the time I exited the motorway. On the trip through sububia to my home I was stopped 3 times at traffic lights and each time the engine auto-stop worked OK when I was stationary. When I got home the trip read 57.1 mpg (4.95 l/100k).

I am sure that this behaviour is consistent with the DPF regenerating - I guesstimate it did this for about 30 minutes and 28 miles - but there was no light or indication in the instrument display.  It may be my imagination - but during the period when the DPF was possibly regenerating the car felt considerably more lively. On the motorway I had to give it a burst to safely overtake some lorrries and it felt just like my previous i30 with a healthy and strong burst of acceleration.

I won't bore you with the maths - but I have calculated that the average economy during the 30 minute period the DPF was regenerating was about 42 mpg (6.73 l/100k)

[Dazzler]

Very useful and informative .. Thanks Alan 

[Asterix]

Hi Alan

Sounds pretty much like the way my car behaves when I suspect it regenerates.

[eye30]

Unless you have a different handbook to me there is no mention in the book warning of this.

[jem]

Good info You would of thought they would have made it so a light comes on when Regeneration starts,Then you wouldn't have people like me who would be thinking is a diesel the way to go.

[Phil №❶]

There has to be a sensor that triggers the ecu to start regeneration. If we find that, a light could be rigged fairly simply. Need a schematic diagram 

[AlanHo]

Unless you have a different handbook to me there is no mention in the book warning of this.

In my 2012 i30 owners manual it states (page 7-81) :-

Diesel Particulate Filter (If equipped).

The DPF system removes soot emitted from the vehicle.

Unlike a disposable air filter, the DPF system automatically burns (oxidises) and removes the accumulated soot according to the driving condition. In other words, the active burning by engine control system and high exhaust gas temperature caused by normal/high driving conditions burns and removes the accumulated soot.

However, if the vehicle continues to be driven at low speed for long time, the accumulated soot may not be automatically removed because of low exhaust temperature. In this particular case, the amount of soot is out of detection limit, the soot oxidation process by engine control system may not happen and the malfunction indicator light may blink.

When the malfunction indicator light blinks, it may stop blinking by driving the vehicle at more than 60km/h (37 mph) or at more than second gear with 1500-2000 engine rpm for a certain time (about 25 minutes)

If the malfunction indicator light continues to be blinked in spite of the procedure, we recommend that the system be checked by a HYUNDAI authorised repairer.

If you continue to drive with the malfunction light blinking for a long time, the DPF system can be damaged and fuel consumption may worsen.

CAUTION - Diesel fuel

it is recommended to use the regulated automotive diesel fuel for vehicle equipped with the DPF system

If you use diesel fuel including high sulfur (more than 50 ppm sulfur) and unspecified additives, it can cause the DPF system to be damaged and white smoke can be emitted.

It is not very informative and can be taken two ways. But my reading of this is that the DPF will be "silently" regenerated as required. However if this does not happen because the car is constantly being driven too slowly - a warning light will blink to advise you to give the car a thrashing.

[Shambles]

^-- does your manual really have all those typos?

[eye30]

Not got to that page yet   

Just looked and as you state above.

What appears odd to me is as you drove quite long and at speed then according to the book it shouldn't have activated.

[AlanHo]

Not got to that page yet   

Just looked and as you state above.

What appears odd to me is as you drove quite long and at speed then according to the book it shouldn't have activated.

We drove back from Scotland on the 4th at high speed. I brimmed the tank and the car was only used for local journeys on the 6th and 7th - adding 50 miles to the odo. On the morning of the 8th we travelled down the M42, M5 and M50 to Ross on Wye and back home via Worcester in appalling heavy rain where it was unsafe to cruise at more than 50 mph. This trip added another 140 miles to the odo. That evening I did the hospital visit and the car appears to have regenerated during that trip.

Hence - if I am correct in my supposition - it regenerated after doing only about 15 miles miles after the 140 mile slow motorway round trip (and only 235 miles after the end of the fast trip from Scotland).

Something doesn't seem quite right, does it?.....................

[eye30]

Something doesn't seem quite right, does it?.....................

No..

Here is something to check out.

On the new shape one of the instruments tells you how long you have had the engine running. 
If you zero it and then when it next regenerates zero and then the next.

See if it is time related action?

[Phil №❶]

Something doesn't seem quite right, does it?.....................

Wait a minute, the car probably has a sensor which detects back pressure which is a result of soot deposits. These deposits will build up according to driving conditions and will not be at a set interval.

- If exhaust temps are cool, due to short trips or low speeds, soot will deposit.
- If roads are wet, spray will cool the exhaust & soot will deposit.
- High speed freeway driving in normal mode, will still deposit soot.

When DPF regen is activated, we know extra fuel is supplied to aid exhaust temp increase, coupled with sufficient engine revs to facilitate the regen, both have to be present to remove deposits.

According to my logic, it would not be possible to anticipate exactly when a DPF regen is going to take place.

[AlanHo]

Wait a minute, the car probably has a sensor which detects back pressure which is a result of soot deposits. These deposits will build up according to driving conditions and will not be at a set interval.

- If exhaust temps are cool, due to short trips or low speeds, soot will deposit.
- If roads are wet, spray will cool the exhaust & soot will deposit.
- High speed freeway driving in normal mode, will still deposit soot.

When DPF regen is activated, we know extra fuel is supplied to aid exhaust temp increase, coupled with sufficient engine revs to facilitate the regen, both have to be present to remove deposits.
According to my logic, it would not be possible to anticipate exactly when a DPF regen is going to take place.

The DPF is mounted immediately on the outlet of the turbo where exhaust gases are at their hottest. Hence the DPF will not be affected by water spray off the road - it is tucked too high up between the engine and bulkhead.

[Phil №❶]

Scratch point 2 then 

[neoto]

Something doesn't seem quite right, does it?.....................

Wait a minute, the car probably has a sensor which detects back pressure which is a result of soot deposits. These deposits will build up according to driving conditions and will not be at a set interval.

- If exhaust temps are cool, due to short trips or low speeds, soot will deposit.
- If roads are wet, spray will cool the exhaust & soot will deposit.
- High speed freeway driving in normal mode, will still deposit soot.

When DPF regen is activated, we know extra fuel is supplied to aid exhaust temp increase, coupled with sufficient engine revs to facilitate the regen, both have to be present to remove deposits.

According to my logic, it would not be possible to anticipate exactly when a DPF regen is going to take place.

Your logic is sound. And my logics was the same, but.... (this is true for previous 2011 generation of i30 diesel):
- it regenerates exactly at 700 km intervals, no matter how and where I drive - winter, summer, city, highway,...
- I could anticipate the next DPF and even trigger it (I just floor the accelerator somewhere around the mark when the DPF should be starting - and it starts...).

However, I have noticed that since 50.000 km mark, my i30 is doing regenerations on each 500km. The last fuel tank saw 3 regenerations - one at the beginning, one in the middle and one in the end of the 1160 km driven. Recently, I mostly do highways (my average speed is around 75 km/h).

[Phil №❶]

Something doesn't seem quite right, does it?.....................

Wait a minute, the car probably has a sensor which detects back pressure which is a result of soot deposits. These deposits will build up according to driving conditions and will not be at a set interval.

- If exhaust temps are cool, due to short trips or low speeds, soot will deposit.
- If roads are wet, spray will cool the exhaust & soot will deposit.
- High speed freeway driving in normal mode, will still deposit soot.

When DPF regen is activated, we know extra fuel is supplied to aid exhaust temp increase, coupled with sufficient engine revs to facilitate the regen, both have to be present to remove deposits.

According to my logic, it would not be possible to anticipate exactly when a DPF regen is going to take place.

Your logic is sound. And my logics was the same, but.... (this is true for previous 2011 generation of i30 diesel):
- it regenerates exactly at 700 km intervals, no matter how and where I drive - winter, summer, city, highway,...
- I could anticipate the next DPF and even trigger it (I just floor the accelerator somewhere around the mark when the DPF should be starting - and it starts...).

However, I have noticed that since 50.000 km mark, my i30 is doing regenerations on each 500km. The last fuel tank saw 3 regenerations - one at the beginning, one in the middle and one in the end of the 1160 km driven. Recently, I mostly do highways (my average speed is around 75 km/h).

So, has your driving pattern changed to cause the 700/500 variation or are you driving the same routes 

[neoto]

Same routes, same driving style. And the switch was not gradual at all - it just started doing 500 km between regenerations.

[Phil №❶]

The only other thing I can think of and it is purely a guess, could the EGR valve be a contributor to soot. As the valve ages, it's performance may contribute to soot. 

[neoto]

Still, the manual says that regenerations should be happening at periods of about 1000 km.
The main Slovenian dealer tested a few cars and discovered that all of them regenerate at 700 km and not at 1000 km. Unfortunately, I did not receive this in a written copy.
Anyway, I will let them explain me why this became 500 km in my case after 1 year (50.000 km) of mostly highways...

[davedicko]

  After reading about the DPF Regeneration it seems to me that the ISG pretty much works when it wants,unlike other manufacturers where its either on or off,I have just taken delivery of a 2012 crdi 128bps style nav,and thought the ISG would be a good feature,it is ( when it works )...........Dave.

[rustynutz]

Welcome to the forum, Dave... 

[AlanHo]

It might throw some light on this discussion if we all re-visit this post...

https://www.i30ownersclub.com/forum/index.php?topic=13595.0

[d3matt]

I've done over 4,000 miles in my i30 now (not yet 6 weeks old!!) and I was wondering if it had done a DPF regeneration.  Not noticed anything different yet, but many times the stop/start is disabled at times when it would normally switch off.
But then I do mostly motorway driving,  so maybe a DPF regeneration isn't needed.

[AlanHo]

My car possibly regenerated 235 miles after I did a 153 mile trip back from Scotland at very high speed. I say 'possibly' because the only symptoms were the ISG stopped activating and the average economy trip suddenly started to fall even though I was cruising gently on a level road at the time.

Since then, I had done a further 243 urban miles when today I was in 50 mph restricted traffic on the M42 and I noticed the average economy trip falling again. When I left the motorway 10 mintues later and was stopped at traffic lights the ISG did not activate but 10 minutes later on town roads it started activating again and the economy trip started to creep up again. I can think of no other reason than the DPF was regenerating yet again.

Unfortunately - on this new model - the instant fuel economy display is a bar graph going from 0 to 50 mpg. Hence it is not possible when cruising the motorway to see what the instant consumption is because it will almost certainly exceed 55 mpg at 60 mph on the flat. When I suspect regeneration is taking place I flick to the instant economy display and can see it showing roughly 35 to 40 mpg.

Because I zero the average economy trip each time I brim the tank - if regeneration occurs only a few miles later it makes a big difference to the average displayed quite quickly. However - as more miles are added the effect is less noticeable. Perhaps this is why I have not been so conscious of regeneration before because I have only recently left the everaage economy display on all the time to check the performance of the new car.

I think I will go back to my old system - drive the car for fun rather than economy and keep an eye on economy by manual calculation each time I brim the tank.

As an aside - I have noticed that the car is now feeling decidedly more lively and feels as spritely - perhaps more so - than my previous i30. I have put 3740 miles on the odometer in 10 weeks from new. I indulged in a drag race today with a young buck in a very noisy (presumably with a tuned engine) Astra who sat alongside me at the lights with his engine screaming - clearly ready to drop the clutch because there were roadworks 150 yards ahead and his lane was coned off into mine. He didn't make it - but it was a very close call. His go-faster stripes, lowered suspension, huge exhaust pipes and baseball cap on backwards did him no favours. However - he got me later - I kept to the 40 mph speed limit and he didn't.