DPF warning lamp with poor fuel economy

[Ben100]

Hi there. New owner and first post, sadly problems already. DPFs and fuel economy have been covered in separate posts but I can't see them related on the same thread so here goes..

At the end of Aug I bought a LWB T32 150 4M Kombi with a manual box. 68 reg with 66k. V smart in grey, twin sliders, heated seats, Nav, reversing camera, tow bar, foldy mirrors - really nice spec. I should be very pleased I guess, however.....

It's first journey was from Brigewater Van Centre to my home in North Bucks; a decent run taken v steadily. It had another run back to Bridgewater and back again (long dull story, returned to fix numerous bodywork items and missing parts that hadn't been completed/supplied before initial collection..)

MPG was 36 which was disappointing given the van was empty apart from myself and 2 boys. Looking on threads here I might have hoped for something in the forties?

I now average 26 MPG. No lead footing, just regular driving, some duals, some city driving. A few tools onboard but nothing too heavy.

Last week the DPF warning light started combining on intermittently. I called into my local van centre, they hooked it up to diagnostics and there was no record of the warning lamp (typically this wasn't on at the time). It had various faults recorded and they were then closed down. Does this make any sense? A picture of them is (hopefully) attached.

Watching the clip of the Aussie chap venting about DPFs, I wondered if it could be an airflow sensor issue and therefore excessive fuel usage?

Has anyone experienced the same, or does my MPG sound normal.

At times the van feels awkward to drive in the right gear; the dish will tell me to shift from 5th to 6th but when I do, there's no torque so 6th just feels like an overdrive cruising gear. With this in mind and before the DPF lamp came on I was considering a Revo remap and hoped it may also improve economy.

Ben

 

[mmi]

Last week the DPF warning light started combining on intermittently

What kind of driving you did before the light came on (the last 30 miles before)? Did you drive with fuel low light on? Fuel low light inhibits DPF regeneration thus turning DPF warning on fairly soon.

there was no record of the warning lamp

True, it's not a fault thus not logged in fault memory.

 

[Ben100]

Hi Robert - no half a tank.

Why wouldn’t it be recorded as a fault if the dpf amber lamp came on?

 

[ThreeBridgeT6]

Hi @Ben100. I have a 19 plate T30 204DSG with full camper conversion, with around 5500 on the clock. It has mixed use - quite a lot of short journeys around town, and some longer stuff including trips away. I log my consumption through the Road Trip app and as you can see from the attached snap, my consumption varies wildly. A couple of these are skewed by my forgetting to put the info until a short while after I've filled up, but it's a pretty accurate picture. As you're 4M then you're probably going to be slightly more thirsty than me, but this will be compensated by your 150 to my 204. I think the honest answer is they're generally thirsty. I still get 45mpg out of my 14 year old 3 litre Merc with 165K on the clock on a run, and early 30s round town.

 

[mmi]

Why wouldn’t it be recorded as a fault if the dpf amber lamp came on?

I think it's considered to be still within engine's normal working envelope for a while - just an early warning. VW's way of thinking
However, if the DPF regeneration isn't allowed to take place eventually there will be a fault recorded.

 

[DaveD]

At times the van feels awkward to drive in the right gear; the dish will tell me to shift from 5th to 6th but when I do, there's no torque so 6th just feels like an overdrive cruising gear.

Ignore the display, use your own judgement, the van can't see the road ahead, you can.
I have no idea why VW think we all need to be told when to change gear, anybody that needs the display to tell them when to change gear should buy the DSG version instead, no offence intended.

 

[huw169]

Lol, as a DSG driver, no offence taken!
I agree with you.

 

[Julian Kavanagh]

Hi there. New owner and first post, sadly problems already. DPFs and fuel economy have been covered in separate posts but I can't see them related on the same thread so here goes..

At the end of Aug I bought a LWB T32 150 4M Kombi with a manual box. 68 reg with 66k. V smart in grey, twin sliders, heated seats, Nav, reversing camera, tow bar, foldy mirrors - really nice spec. I should be very pleased I guess, however.....

It's first journey was from Brigewater Van Centre to my home in North Bucks; a decent run taken v steadily. It had another run back to Bridgewater and back again (long dull story, returned to fix numerous bodywork items and missing parts that hadn't been completed/supplied before initial collection..)

MPG was 36 which was disappointing given the van was empty apart from myself and 2 boys. Looking on threads here I might have hoped for something in the forties?

I now average 26 MPG. No lead footing, just regular driving, some duals, some city driving. A few tools onboard but nothing too heavy.

Last week the DPF warning light started combining on intermittently. I called into my local van centre, they hooked it up to diagnostics and there was no record of the warning lamp (typically this wasn't on at the time). It had various faults recorded and they were then closed down. Does this make any sense? A picture of them is (hopefully) attached.

Watching the clip of the Aussie chap venting about DPFs, I wondered if it could be an airflow sensor issue and therefore excessive fuel usage?

Has anyone experienced the same, or does my MPG sound normal.

At times the van feels awkward to drive in the right gear; the dish will tell me to shift from 5th to 6th but when I do, there's no torque so 6th just feels like an overdrive cruising gear. With this in mind and before the DPF lamp came on I was considering a Revo remap and hoped it may also improve economy.

Ben

View attachment 134427

Sorry, new to this but so hacked off with my van, thought I'd moan and hope someone would see and either sympathise or say they've had same experience / suggest solutions. I realise and apologise for probably responding to someone's related post but don't really understand how this forum works (as in, it's not clear to me how to post a new subject)
T6 Kombi 4M 204 manual (they do exist) 2018, bought pre-reg with 27 miles.
Live on a hill and 20 mile, B and A road drive to work, and back, averaged 44 mpg from 'new', at first.
Drove it too carefully I think and things soon started clogging up. Van is capable of 50 mpg if carefully driven, occasionally but, if driven carefully, the walk away from it is always to the sound of that fan doing something, including running down the battery (recently replaced) and producing a worrying smell. Then the van seems to pay me back with sub 30mpg for the same journey & circumstances.
I haven't yet found the sweet spot of driving it hard to clear the particulate, so oscillate from a tank that lasts as much as 600 miles to as little as 390.
Would consider selling it but now there have been 8 warranty-covered repairs / replacements inc. DPF and a burnt-through exhaust pipe section that fed fumes threw the air vent, I want to think, surely this post-emissions scandal, value-engineered Friday PM van in beautiful, met grey sat nav heated seats Highline 56k can't have anything more go wrong!?

Hopefully someone will respond and, more hopefully, I shall get a notification, and find it.

Have a good weekend in the meantime all.

JK

 

[Pete C]

How often do you do a drive of more than your 20 miles to/from work ?

Pete

 

[JDC]

I get that smell on mine as well but it appears its just the DPF doing a regen surely?? I give mine a blast on the motorway to clear the soot levels and that seems to cure my van. Should have a little sticker on the windscreen telling you what to do when the light comes on or in the handbook. Drive at 2000 revs but make sure the engine has warmed up first. It takes mine about 20 min. May just need to blast more often, they aren't very good plodding around doing 20 miles a day. I go mad at my lad for doing it!!!!

 

[Howzat]

It takes 15-20 minutes at 2k - 2.6k ish revs to complete a regen, so even on B roads just stay in 2nd and 3rd and keep the revs at 2k or above for this length of time once you see the temperature gauge at operating temp (12 o'clock)
The trick is knowing when you're van is trying to regen. There are a few signs to look out for, the main one being increased revs at idle, and once you know when just drive it like stated above.
Search the forum for 'regen'

EDIT. Keep the fuel tank above 9 o'clock otherwise regens wont run at all.

 

[Dellmassive]

44-50mpg.

On a 204 4M,with Hilly A and B roads .

Thats very optimistic in my eyes.

We have a 204 DSG panel van.


********************

This is what we get:

Full tank averages are 25-35mpg

average fill volume @ 65ltrs

worst tank range: 304miles

best tank range: 507miles

average tank range: 400miles

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The other mechanical items are common on these van, cracked EGR exhaust pipe and dpf clean, EGR clean/replacement etc.


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@Dellmassive`s T6 T32 Sportline 204 LWB DSG PV MY18 - Van Adventure

@Dellmassive`s T6 T32 Sportline 204 LWB DSG PV MY18 - Van Adventure as you all know my main contribution to the Forum is my "How i Done It" threads, over here: ++++ https://www.t6forum.com/threads/dellmassive%E2%80%99s-how-i-done-it-blogs.8510/ ++++ which is great and well, but i...

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..

 

[huw169]

********************

This is what we get:

Full tank averages are 25-35mpg

average fill volume @ 65ltrs

worst tank range: 304miles

best tank range: 507miles

average tank range: 400miles

**********************

This is the same as my 199

 

[Julian Kavanagh]

How often do you do a drive of more than your 20 miles to/from work ?

Pete

Semi retired now so very rarely do short journeys. NB my regen light has only come on a couple of times in 5 years. Interesting what is said re. low fuel level. Overall, I don't think it's plausible that a van can have such a range of mpg returns with what will be similar driving style/journeys and am convinced the tech or bolt-on devices aren't working in harmony

 

[JDC]

Mines the same. Less than a quarter of tank, the van appears to do constant regen, unusual fuel smell and rubbish mpg. More than a quarter of a tank, no issues whatsoever. Mines used by my lad doing short journeys to work and back, I have the pleasure running it up the motorway to clean the DPF. Do you think VW could sort it Julian??

 

[huw169]

Mines the same. Less than a quarter of tank, the van appears to do constant regen, unusual fuel smell and rubbish mpg. More than a quarter of a tank, no issues whatsoever. Mines used by my lad doing short journeys to work and back, I have the pleasure running it up the motorway to clean the DPF. Do you think VW could sort it Julian??

That does not sound right. Low fuel level typically inhibits regen.
Is your van older than 2019? If so, might be worth getting VW to put the updated software on. There were a number of fixes.

 

[Julian Kavanagh]

Mines the same. Less than a quarter of tank, the van appears to do constant regen, unusual fuel smell and rubbish mpg. More than a quarter of a tank, no issues whatsoever. Mines used by my lad doing short journeys to work and back, I have the pleasure running it up the motorway to clean the DPF. Do you think VW could sort it Julian??

(Huw's suggestion sounds worth pursuing)
Can't say I completely buy regen not working if less than 1/4 full. But there was one occasion in France when the mpg was plummeting and we only just made it to fuel station. Continued on motorway with full tank - at 130kph, in 5th for half hour and that next tank lasted over 525 miles.
Have heard regen only happens at at least 70mph, but this too may be old wives' tale.
My current policy is to leave in 1st and 2nd beyond natural rev sound (say 2750 rpm) and then always keep revs at 2000+; keep Start Stop off so I can check idling speed at junctions. This does at least seem to have led to fewer fan over-runs once parked up / switched off

 

[huw169]

Regen is not about speed but revs.
2000 - 2500 rpm is fine. It will regen at idle but takes longer.
Start stop is auto disabled during regen
Less than 1/4 it’s inhibited on older software. Newer software reduces this, but not sure what new limit is. Mine doesn’t seem to care about fuel level now, just gets on with it.

If it’s doing something different then something is not right.

If you never let it finish then it will always feel like it is trying to regen.

 

[JDC]

That does not sound right. Low fuel level typically inhibits regen.
Is your van older than 2019? If so, might be worth getting VW to put the updated software on. There were a number of fixes.

It's a 16 plate T6 140 manual. To clear, I get it on the motorway keep above 2000 revs for about 20min and it clears the soot level enough to stop the regen then I go top up the fuel tank.

 

[DaveD]

It's a 16 plate T6 140 manual. To clear, I get it on the motorway keep above 2000 revs for about 20min and it clears the soot level enough to stop the regen then I go top up the fuel tank.

The 140 suggests it's a Euro 5 engine, i.e. no Adblue. (They upped the power to 150 with the EU 6 version)
These operate in a different way with regards to DPF regens, others more knowledgeable than me might explain.
I've got a Euro 5, manual gearbox 140, I've never seen any lights on or been aware of when it regens in 40K miles of mixed driving but like all engines, short journeys are a MPG killer.