Oil temperature and DPF

[Ecomatt]

9 hours ago, J.R. said:

Not at all sure, I am working from memory and the units being a volume are meaningless when the service limit for the DPF is expressed in grammes.

 

I am probably out by one decimal place in one direction or the other, what I can say with certainty is the the number clicks up one digit every 10000 miles, it was 0.9 (or 9 or 0.09) from 90K miles throught to 100K when it increased to 1.0 (or 10 or 0.1).

 

But despite 2 years of googling nowhere can I find what the service limit is in volume terms or a conversion factor from grammes to volume so I am no closer to knowing how close to full my ECU erroneously believes the DPF to be, I am doing frequent long removal journeys towing trailers at present, 500 miles yesterday, the frequency of regens is far too high and it does not take into account all the passive regeneration going on, I rely heavily on the vehicle at present and need to know if it is going to arbitrarily shut down soon.

As I understand it the service limit is not determined by volume but is by the grams value. If it reaches 45grams or above in load value then VW recommend it to be replaced. If you have any doubts it might be an idea to run some dpf cleaner through it. They do actually work as the fuel is injected after the burn cycle into the combustion chamber and evaporates, being heated again and chemically altered by the cat and then into the dpf. Helping the soot to be burned off. 

[J.R.]

I don't have any doubts, I can measure and take heed of the DPF differential pressure sensor, unfortunately VAG's stupid algorithm doesn't.

 

I agree that the service limit is measured in grammes which is what makes it so feckin stupid that the measuring block data for oil ash is expressed as a volume and nobody can give a correlation between the two.

 

I could use some of your snake oil, it might even lighten the oil ash as it will my wallet but it will not make the slightest bit of difference to the ECU which is going to blindly carry on adding X volume =????? grammes for every 10K miles driven until it decides that its game over, that could happen to me at any time and there is not a thing that I can do about it or even know when it will happen.

 

The only option I can see is telling the ECU that the DPF has been replaced.

 

How in dogs name did we get from having super reliable vehicles after 100 years of development to the overcomplicated shower of **** that we are driving in recent years?

[Ecomatt]

1 hour ago, J.R. said:

I don't have any doubts, I can measure and take heed of the DPF differential pressure sensor, unfortunately VAG's stupid algorithm doesn't.

 

I agree that the service limit is measured in grammes which is what makes it so feckin stupid that the measuring block data for oil ash is expressed as a volume and nobody can give a correlation between the two.

 

I could use some of your snake oil, it might even lighten the oil ash as it will my wallet but it will not make the slightest bit of difference to the ECU which is going to blindly carry on adding X volume =????? grammes for every 10K miles driven until it decides that its game over, that could happen to me at any time and there is not a thing that I can do about it or even know when it will happen.

 

The only option I can see is telling the ECU that the DPF has been replaced.

 

How in dogs name did we get from having super reliable vehicles after 100 years of development to the overcomplicated shower of **** that we are driving in recent years?

Europe and their stupid Euro emissions!

You could always get the DPF cleaned as a prevetative measure. Something that if I plan to keep my current car for another 2 years I will get done.

 

[J.R.]

It is becoming clear that either I am not explaining well enough or you are not understanding what my problem will be.

 

It does not matter how clean my DPF is, whether I run snake oil through it or have it professionally cleaned the ECU will take not the slightest bit of notice it may report actual readings for soot but what triggers the regens and the game over when it believes the oil ash limit is exceeded are the calculated figures.

 

My car thanks to the measures I have implemented (DPF emulator) produces 1/5 of the soot that the algorithm says is there, nonetheless it regens when only 5 or 6g of soot is measured because the calculated value has exceeded 22g.

 

Even if the oil ash were rising at the level the algorithm thinks it is I still have no idea how close I am to the service limit because the stupid thng reports it as a volume and not a mass and nowhere can I find what the service limit is in volume or a conversion factor.

 

Neither can I find out what will actually happen when the calculated volume does exceed the still unknown service limit.

 

Do you understand my concern now? It is not that my DPF might be clogged, I know full well that it isn't, if only the ECU algorithm would take heed of its own measured readings.

 

 

[langers2k]

I never found an official limit for the oil ash volume. On some forums they mention 175ml but plenty of folk have reported 200-250ml or even 300ml+. That suggests that nothing happens assuming it can still burn the soot off.

 

I never saw much of a correlation between measured and calculated soot mass so that's completely normal. I don't think 'calculated mass' takes into account passive regen so it often much higher.

 

The 45g limit only applies to soot mass, if it hits 45g it's no longer safe to regenerate so needs replacing or removing for cleaning. This is completely unrelated to the oil ash volume.

[J.R.]

Thankyou so much Langers, that is the first reassurance I have had on the subject.

 

I am doing long autoroute journeys towing very large frontage heavily loaded trailers, the engine is so loaded that the fuel consumption drops from the usual 55mpg to 28mpg, 500 miles on Saturday, almost every time I stopped for fuel or a pee the fans were running as they were on arrival, in urban driving it was regenning every 100 miles despite only showing 6g of soot, it seems the same is happening even when under constant passive regeneration over 500 miles.

 

It's the fuel consumed in doing so that I begrudge.

 

My UK neighbour has the same engine in an Octavia, he made sure to buy one that had not had the emissions "fix" done and has kept it that way, he does mainly short journeys now but has only ever heard the fan running on shutdown twice in several years.

[langers2k]

I wouldn't be surprised if the extra load increased under bonnet temps so it may not have been a interrupted regen causing the fan to run on.

 

Running a pre-fix software may help reduce the number of regens. My pre-fix CFHC Octavia would regen every 300-350 miles so around a third as often. I've no idea how much fuel that would save but only a couple of litres per tank at a guess...

 

TBH - I just left my car to do it's thing. As long it's not using oil and the oil ash volume is increasing consistently, it's probably fine.

[Ootohere]

@Kachaka  How are things this week?

 

How long from a cold start until the Coolant gauge shows 90*oC  & how many miles before the Oil Temp shows 50*oC and is the oil temp still not getting to above 80*oC if you are maybe driving for 30 minutes or more?

[Kachaka]

On 22/01/2022 at 15:09, roottoot said:

@Kachaka

Has your car had the VW Group Emissions Cheat FIX carried out, so the new Engine Management and a flow device fitted in the Air Intake?

Was that done before you got it or since?

 

http://skoda-auto.com/services/recall-actions

 

Checked with the VIN of the car and shows the car is not affected! 

[Kachaka]

1 hour ago, roottoot said:

@Kachaka  How are things this week?

 

How long from a cold start until the Coolant gauge shows 90*oC  & how many miles before the Oil Temp shows 50*oC and is the oil temp still not getting to above 80*oC if you are maybe driving for 30 minutes or more?

I booked an appointment to do an assessment of the DPF on 1st of February.

 

Oil temp shows over 50*oC after approximately 4-5 miles but even after 30 minutes driving it is still between 70-75. 

[Ootohere]

So best check if showing not affected because the fix was done.  Is there a sticker in the spare tyre well?   Ask Skoda UK customer services if not affected because they already were allowed to tick your car off the list?.   Easy to look for the flow device in the  air intake.      

Edited 24 January, 2022 by roottoot

[Ootohere]

What milage had the car done and when was the oil changed last?   Is it 5w 30 FS III that is used.  So to VW 504 00 / 507 00.

[Ecomatt]

5 hours ago, J.R. said:

It is becoming clear that either I am not explaining well enough or you are not understanding what my problem will be.

 

It does not matter how clean my DPF is, whether I run snake oil through it or have it professionally cleaned the ECU will take not the slightest bit of notice it may report actual readings for soot but what triggers the regens and the game over when it believes the oil ash limit is exceeded are the calculated figures.

 

My car thanks to the measures I have implemented (DPF emulator) produces 1/5 of the soot that the algorithm says is there, nonetheless it regens when only 5 or 6g of soot is measured because the calculated value has exceeded 22g.

 

Even if the oil ash were rising at the level the algorithm thinks it is I still have no idea how close I am to the service limit because the stupid thng reports it as a volume and not a mass and nowhere can I find what the service limit is in volume or a conversion factor.

 

Neither can I find out what will actually happen when the calculated volume does exceed the still unknown service limit.

 

Do you understand my concern now? It is not that my DPF might be clogged, I know full well that it isn't, if only the ECU algorithm would take heed of its own measured readings.

 

 

The ECU will trigger an active regen based on the following 

 

The soot load of the particulate filter is calculated by two pre-programmed load models in the ECM.
One load model is determined from the user driving style and values from the exhaust gas temperature sensor and lambda 
probe signals.
Another soot load model is the flow resistance of the particulate filter. It is calculated using data from the G450 Exhaust 
Pressure Sensor 1, the exhaust gas temperature sensors, and the calculated exhaust mass flow from the ECM.

 

We will never know the actual values predetermined by VW as they will be kept out of the public domain. From what I have read and understand I dont think there is a service upper limit based on oil load alone. From what I gather it is all based on flow. You can mathematically work out the weight of the oil volume. But first you need to know how much the oil residue would weigh per Litre to gram. Far beyond my skill set as I am not a scientist with the correct equipment to be able to measure

[Kachaka]

2 hours ago, roottoot said:

What milage had the car done and when was the oil changed last?   Is it 5w 30 FS III that is used.  So to VW 504 00 / 507 00.

I will contact Skoda UK and ask them.. don’t have a spare tyre neither any stickers.

 

the car is at 140,000 miles and used only 5w 30 FS which is recommended from VW

[Berty21]

Hi just read about your probs.... I have the same car mine has done 300,000 plus and it does in winter time take a lot long to heat up ,so its prob a winter thing...

if your in limp home mode use a code reader to clear off any codes (£15 on amazon) this might keep limp home at bay.

there is no need for speed to clear out DPF JUST HIGH REVS....

If it was mine i would change air filter as a dirty one will effect power and fuel consumption

and do a oil and filter change.... use OE or Mahle filters and Castrol edge 5W30 LL 

Fill tank with Shell or BP expensive  Diesel ( do this every 3rd fill up anyway)

get    JLM Diesel Extreme Clean 1000ml  this does work!!!

Now take a long Day trip say at least 100miles on the motorway after the first 5 miles use low gears to get oil hot when its 70+ use low gears

and keep car 500rpm under the red line while cruising  for 5 miles then a bit of cruising in 5th gear for a 1mile and just repeat for the journey.

Come of at junctions and accelerate back on-again

the idea is to get the exhaust HOT and burn of all the crap. If your in limp home mode its still achievable maybe use A roads instead of the motorway.

The higher octane fuel will help with this and it does not produce much ash if any at all so good for your DPF.

PS EVERY GARAGE WILL SAY ITS YOUR DPF its just a easy target

 

 

 

 

[Kachaka]

2 hours ago, Berty21 said:

Hi just read about your probs.... I have the same car mine has done 300,000 plus and it does in winter time take a lot long to heat up ,so its prob a winter thing...

if your in limp home mode use a code reader to clear off any codes (£15 on amazon) this might keep limp home at bay.

there is no need for speed to clear out DPF JUST HIGH REVS....

If it was mine i would change air filter as a dirty one will effect power and fuel consumption

and do a oil and filter change.... use OE or Mahle filters and Castrol edge 5W30 LL 

Fill tank with Shell or BP expensive  Diesel ( do this every 3rd fill up anyway)

get    JLM Diesel Extreme Clean 1000ml  this does work!!!

Now take a long Day trip say at least 100miles on the motorway after the first 5 miles use low gears to get oil hot when its 70+ use low gears

and keep car 500rpm under the red line while cruising  for 5 miles then a bit of cruising in 5th gear for a 1mile and just repeat for the journey.

Come of at junctions and accelerate back on-again

the idea is to get the exhaust HOT and burn of all the crap. If your in limp home mode its still achievable maybe use A roads instead of the motorway.

The higher octane fuel will help with this and it does not produce much ash if any at all so good for your DPF.

PS EVERY GARAGE WILL SAY ITS YOUR DPF its just a easy target

 

 

 

 

I just ordered the car code reader from Amazon to delete the error. In the next couple of days when my tank is almost empty, I will put the DPF cleaner, fill tank with Shell V Power and drive on the motorway on second and third gear at around 4000rpm. Also will do couple of accelerations from a junction and see if there is any improvement!

will even see if the oil temp goes above 80 degrees

[Kachaka]

Does anybody know why I cant erase the codes? The car is in ignition and the engine is off.. 

[J.R.]

Did it find any codes to erase?

 

Did you make a note of them?

 

What were they?

 

If its a cheap P.O.S. then it won't be able to access the relevant modules to erase the codes especially mission critical ones like ABS, airbags etc.

[ChoonDoode]

On 24/01/2022 at 00:08, J.R. said:

How in dogs name did we get from having super reliable vehicles after 100 years of development to the overcomplicated shower of **** that we are driving in recent years?

 

Because things have now been designed to wear out. I've got a selection of tools left to me by my Grandad. They're made of toughened wood and steel. Some are well more than double my age and they're in perfect working order. On the other hand, I was forever replacing some of the tools I used to have to use. Cheap plastic and weaker aluminium.

 

 

[Ootohere]

@Berty21What Cetane does the Shell V-Power diesel show on the pump as being higher than the Regular Diesel's cetane.   (It is Cetane not Octane)

You could just add the readily available Cetane Booters. 

Edited 27 January, 2022 by roottoot

[BogdanB]

Any way to trick the soot mass calculated? It's really anoying since it goes up at almost a constant rate and getting way more regens now in the winter, since i let the car sit with engine running while i defrost / clean snow.

[Ecomatt]

2 hours ago, BogdanB said:

Any way to trick the soot mass calculated? It's really anoying since it goes up at almost a constant rate and getting way more regens now in the winter, since i let the car sit with engine running while i defrost / clean snow.

Not that I am aware of. More to the point would you want to, as it would just eventually block up totally.

[BogdanB]

Soot mass measured says otherwise though 🤔

[langers2k]

Just leave it to do it's thing...

 

If the calculated value is causing a few more regens, apart from a small amount of fuel usage, it shouldn't make much difference to anything else

[J.R.]

Mine was regenning once again straight after a 500 mile 120kph autoroute journey towing a 1400kg trailer VCDS showed 210kms since the last regen which means that despite the high revs, high load, high oil temperature it will already have regenned 3 times on the autoroute, the VAG emissions fix sucks!!

 

Mine produces very little soot as the EGR is disabled by an emulator it regens on a measured 4-6g of soot, it will have been zero on the autoroute.

 

Using VCDS I managed to tell it that it had a new DPF but all this will change is the oil ash volume figure should I choose to view it in VCDS, I also tried a couple of different adaptions those of the DPF pressure sensor and also another related sensor, I noticed afterwards that the calculated soot value had dropped to zero but it was rising before my eyes with the engine ticking over.

 

There is one extreme measure that I am considering but I will only do it when I know I will be at base with a working computer & VCDS for an extended period you can actually switch off the automatic regens, I would like to do this and see exactly how many miles the car covers before the measured soot value reaches the pre "fix" threshold of 30g and then do a forced regen while driving.

 

If it is as infrequent as I believe it will be then I would consider leaving it and doing a regen as part of periodic maintenance.