DPFs. More hassle than they're worth?
Discussion
Have an Audi with the 3.0 TDI engine. Recently been having DPF issues. Did a 500 mile motorway journey without issue (mostly doing 60-65mph), and as soon as I go out the next day the DPF light pops up. Took it for a spirited drive, when it decided to go into limp mode. Attempted a forced regeneration and the soot level just kept increasing. Currently on 39g with no clue what to do next. 70% of my driving is on the motorway however previous to my ownership the car was doing just 5k a year, possibly round town. I wouldn't expect it to clog like this though after such a long run. Most stories you hear are from people who drive around town and never allow the car long runs to regen properly.
The common solution seems to be gut the DPF and have it mapped out. Same goes for the EGR system and even Adblue. Which makes me wonder, are these systems causing more problems than they intend to solve?
The common solution seems to be gut the DPF and have it mapped out. Same goes for the EGR system and even Adblue. Which makes me wonder, are these systems causing more problems than they intend to solve?
A DPF is an emissions control device; it's designed to make the particulate emissions from a diesel engine vaguely acceptable. They certainly have downsides, but without them diesels would have been implicitly banned a decade ago. Mostly (but obviously not exclusively) they fail when people use diesel powered cars for things they're really not suited for.
Driving a diesel which was type approved with a DPF without one is, quite rightly, a criminal offense.
Driving a diesel which was type approved with a DPF without one is, quite rightly, a criminal offense.
kambites said:
A DPF is an emissions control device; it's designed to make the particulate emissions from a diesel engine vaguely acceptable. They certainly have downsides, but without them diesels would have been implicitly banned a decade ago. Mostly (but obviously not exclusively) they fail when people use diesel powered cars for things they're really not suited for.
Driving a diesel which was type approved with a DPF without one is, quite rightly, a criminal offense.
THIS! 1000 times this!Driving a diesel which was type approved with a DPF without one is, quite rightly, a criminal offense.
Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car!
Makes me laugh how many people buy the wrong car for their needs because they get suckered in by "high mpg" figures (which we all know are not even close to real world) And seem to forget that currently diesel is 10p a litre more than petrol so even if your getting 45mpg. Cost wise its equivalent to 35mpg in a petrol car. AND you don't have DPF, AdBlue and all the other emissions crap that goes wrong!
Oh and the answer for a DPF regen is NOT a "spirited drive" (despite what the PH big dick swingers think) Its a relatively stable 50-60mph for a good 30-60mins! Caining it makes the problem worse!
I have a 335d xdrive BMW. No DPF issues in 54k miles. As stated it needs occasional long distances to keep it clear.
Not sure about the diesel price v petrol. It’s more like 45mpg is equivalent to 42 mpg for petrol prices. A diesel is about the torque really (not comparing to EV torque delivery, here).
Not sure about the diesel price v petrol. It’s more like 45mpg is equivalent to 42 mpg for petrol prices. A diesel is about the torque really (not comparing to EV torque delivery, here).
BunkMoreland said:
Makes me laugh how many people buy the wrong car for their needs because they get suckered in by "high mpg" figures (which we all know are not even close to real world) And seem to forget that currently diesel is 10p a litre more than petrol so even if your getting 45mpg. Cost wise its equivalent to 35mpg in a petrol car. AND you don't have DPF, AdBlue and all the other emissions crap that goes wrong!
You’re laughing, possibly at the wrong people - how on earth should non car people, or non mechanically minded people know any better? The people who are laughing are the dealers who sell diesels to people with completely inappropriate use cases. My partner (before I met her) was sold a Audi A1 diesel even after specifically asking would it be OK for short city journeys with the occasional (2 monthly) long trip, and was still sold a diesel even though petrol alternatives were available. She’s now in a petrol Mazda 2.
I bought a Discovery Sport diesel (which has additional design related DPF issues) when no petrol alternative was available. When the petrol DS was launched, LR suddenly developed a conscience and had a ‘Is diesel right for you’ type checklist.
Dashnine said:
You’re laughing, possibly at the wrong people - how on earth should non car people, or non mechanically minded people know any better? The people who are laughing are the dealers who sell diesels to people with completely inappropriate use case.
For the huge majority of buyers, a car is a white goods item first, and perhaps a status symbol second. They have no interest in or knowledge of what they're buying beyond what they're told by the dealer. For a long time, diesels were grossly mis-sold to an awful lot of people. A lot of people will, rightly or wrongly, when they need a washing machine or oven, go into Currys and ask the salesman what would suit them; why would a car be any different for those people?
Megaflow said:
DPF's work if the engine is operated in the correct manner, and the correct manner means load & temperature.
Pootling around at 1500rpm and minimal throttle will lead to a blocked DPF.
My wife drove a VW diesel for 8yrs like that and it never gave a single issue.Pootling around at 1500rpm and minimal throttle will lead to a blocked DPF.
This idea of taking them for a fast run every week is nonsense - the dpf never gets anywhere near hot enough to passive regen as the engine is so lightly loaded in normal UK use. Indeed we took it across the M62 and back one weekend and then it did an active regen on the school run on Monday morning.
It active regenned around every 300 miles for 10 mins or so, and would start one within a couple of miles from home, so it didn't need a hot engine. With her use (lots of 4 mile trips to school or shops) she was forever stopping it mid-regen and even that didn't cause any issue.
The only thing I will say is we always ran it on V-Power. The cost was a bit galling but she only used a tank a month.
I did chicken out at 8yrs - felt like it was tempting fate to keep it - and dumped it and bought a petrol.
Edited by Sheepshanks on Sunday 15th September 12:53
BunkMoreland said:
THIS! 1000 times this!
Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car!
Makes me laugh how many people buy the wrong car for their needs because they get suckered in by "high mpg" figures (which we all know are not even close to real world) And seem to forget that currently diesel is 10p a litre more than petrol so even if your getting 45mpg. Cost wise its equivalent to 35mpg in a petrol car. AND you don't have DPF, AdBlue and all the other emissions crap that goes wrong!
Oh and the answer for a DPF regen is NOT a "spirited drive" (despite what the PH big dick swingers think) Its a relatively stable 50-60mph for a good 30-60mins! Caining it makes the problem worse!
….Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car!
Makes me laugh how many people buy the wrong car for their needs because they get suckered in by "high mpg" figures (which we all know are not even close to real world) And seem to forget that currently diesel is 10p a litre more than petrol so even if your getting 45mpg. Cost wise its equivalent to 35mpg in a petrol car. AND you don't have DPF, AdBlue and all the other emissions crap that goes wrong!
Oh and the answer for a DPF regen is NOT a "spirited drive" (despite what the PH big dick swingers think) Its a relatively stable 50-60mph for a good 30-60mins! Caining it makes the problem worse!
Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car! laugh
…..
10 years in, average 60 mpg
£35 annual tax
0 Dpf errors
You absolute loon
The answer is.. definitely don’t remove it. Easy way to get slapped with a big fine (£1k) and forced to rectify or scrap the car…
Most companies that offer it have a disclaimer like the below:
“Our DPF Removal service is sold for off-road use only. Removal of a DPF will almost invariably make your vehicle illegal for use on a public road.”
There have been plenty of examples of this getting enforced on MOT testers and garages.
Not to mention, it’s morally a rubbish thing to do
Most companies that offer it have a disclaimer like the below:
“Our DPF Removal service is sold for off-road use only. Removal of a DPF will almost invariably make your vehicle illegal for use on a public road.”
There have been plenty of examples of this getting enforced on MOT testers and garages.
Not to mention, it’s morally a rubbish thing to do
I would guess a faulty pressure sensor, get yourself the VAG DPF app on android and a ELM327 bluetooth reader / dongle "vgate" ones work well, on the app you have to select the correct engine code, it will tell you everything happening on an active dpf regen, yes on VAG cars they will regen at 1500 rpm, even on idle, because it's the temperature of the DPF that matters, when it hits over 600c the regen will happen quickly, it does this by adding extra diesel called post injection, when you can also see grey smoke when you stop, passive regen happens under certain parameters, usually on a dual carriageway. (They will also regen pootling around town, you'll see the smoke when you stop and set off again)
Thrashing it will be counter productive to a regen, because it will slow it down, or it will stop, or lifting your foot off the throttle, on a VAG common rail tdi, the best method I've discovered after doing 100's is 4th gear at about 60 mph the rpm's will be about 2000 to 2200, you can thrash it a little to get it hotter, then aim for a hill at that speed, once it hits 600 plus c on the dpf the regen happens quickly, probably 10-12 mins.
It's not a brilliant idea to switch them off during an active regen because of the increased risk of fuel dilution, people do that everyday.
Thrashing it will be counter productive to a regen, because it will slow it down, or it will stop, or lifting your foot off the throttle, on a VAG common rail tdi, the best method I've discovered after doing 100's is 4th gear at about 60 mph the rpm's will be about 2000 to 2200, you can thrash it a little to get it hotter, then aim for a hill at that speed, once it hits 600 plus c on the dpf the regen happens quickly, probably 10-12 mins.
It's not a brilliant idea to switch them off during an active regen because of the increased risk of fuel dilution, people do that everyday.
My sister-in-law bought a Skoda Rapid 1.6 diesel in 2013 and still has it. Amazingly suffered no DPF problems. She lives on Jersey and a journey as long as 10 miles is rare. Never driven over 40mph & mainly between 20 & 30.
I'm surprised VAG even sell diesels on Jersey. A document on their web-site in 2013 stated diesels were not recommended for small islands, & even mentioned Jersey as such an island!
I'm surprised VAG even sell diesels on Jersey. A document on their web-site in 2013 stated diesels were not recommended for small islands, & even mentioned Jersey as such an island!
James6112 said:
BunkMoreland said:
THIS! 1000 times this!
Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car!
Makes me laugh how many people buy the wrong car for their needs because they get suckered in by "high mpg" figures (which we all know are not even close to real world) And seem to forget that currently diesel is 10p a litre more than petrol so even if your getting 45mpg. Cost wise its equivalent to 35mpg in a petrol car. AND you don't have DPF, AdBlue and all the other emissions crap that goes wrong!
Oh and the answer for a DPF regen is NOT a "spirited drive" (despite what the PH big dick swingers think) Its a relatively stable 50-60mph for a good 30-60mins! Caining it makes the problem worse!
….Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car!
Makes me laugh how many people buy the wrong car for their needs because they get suckered in by "high mpg" figures (which we all know are not even close to real world) And seem to forget that currently diesel is 10p a litre more than petrol so even if your getting 45mpg. Cost wise its equivalent to 35mpg in a petrol car. AND you don't have DPF, AdBlue and all the other emissions crap that goes wrong!
Oh and the answer for a DPF regen is NOT a "spirited drive" (despite what the PH big dick swingers think) Its a relatively stable 50-60mph for a good 30-60mins! Caining it makes the problem worse!
Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car! laugh
…..
10 years in, average 60 mpg
£35 annual tax
0 Dpf errors
You absolute loon
150ppl @ 45mpg diesel v 140ppl @ 35mpg petrol over 1000 miles would be 101L used for diesel @ £151.52 v 129L used for petrol @ £181.33
Dashnine said:
You’re laughing, possibly at the wrong people - how on earth should non car people, or non mechanically minded people know any better? The people who are laughing are the dealers who sell diesels to people with completely inappropriate use cases.
To be fair. Its true that shiny suited sales people did sell regardless of whether it was correct for their needs. But at some point personal responsibility should kick in No? Everyone knows 90%+ of sales people are dishonest!
James6112 said:
….
Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car! laugh
…..
10 years in, average 60 mpg
£35 annual tax
0 Dpf errors
You absolute loon
Well as you've managed that, then that's absolutely true for every diesel driver isn't it! Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car! laugh
…..
10 years in, average 60 mpg
£35 annual tax
0 Dpf errors
You absolute loon
There are ZERO problems for everyone with any diesel car and its emissions systemsMDMA . said:
Maths not a strong one for Bunky.
150ppl @ 45mpg diesel v 140ppl @ 35mpg petrol over 1000 miles would be 101L used for diesel @ £151.52 v 129L used for petrol @ £181.33
You're right. I should have added on that Diesel cars are more expensive to buy in the first place. Lets pick a ball park figure of 2K (Audi A3 35 TDI vs 35 TFSI as an example)150ppl @ 45mpg diesel v 140ppl @ 35mpg petrol over 1000 miles would be 101L used for diesel @ £151.52 v 129L used for petrol @ £181.33
So you need to drive thousands of miles to offset that fuel saving. My quick maths suggest 66K at £30 saved per 1000miles
I switched to a bmw 330d from a 335i a few years ago. 37mpg in the diesel vs 27mpg in the petrol, more than offsets the extra 7p a litre that diesel costs over petrol.
As for the dpf, my car is on 162k and still has a dpf. I had to pay someone £250 a few years back to clean it out, but it's still there. I understand it stopped regening because the glow plugs needed changing.
All sorted now, hoping to get the car to 200k and still on the original dpf.
As for the dpf, my car is on 162k and still has a dpf. I had to pay someone £250 a few years back to clean it out, but it's still there. I understand it stopped regening because the glow plugs needed changing.
All sorted now, hoping to get the car to 200k and still on the original dpf.
aproctor1 said:
kambites said:
Driving a diesel which was type approved with a DPF without one is, quite rightly, a criminal offense.
I'll stick some more coal on the fire tonight,.just for you.“Take that Greta Thunberg”
Edited by Gibbler290 on Sunday 7th April 19:33
BunkMoreland said:
Dashnine said:
You’re laughing, possibly at the wrong people - how on earth should non car people, or non mechanically minded people know any better? The people who are laughing are the dealers who sell diesels to people with completely inappropriate use cases.
To be fair. Its true that shiny suited sales people did sell regardless of whether it was correct for their needs. But at some point personal responsibility should kick in No? Everyone knows 90%+ of sales people are dishonest!
James6112 said:
….
Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car! laugh
…..
10 years in, average 60 mpg
£35 annual tax
0 Dpf errors
You absolute loon
Well as you've managed that, then that's absolutely true for every diesel driver isn't it! Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car! laugh
…..
10 years in, average 60 mpg
£35 annual tax
0 Dpf errors
You absolute loon
There are ZERO problems for everyone with any diesel car and its emissions systemsMDMA . said:
Maths not a strong one for Bunky.
150ppl @ 45mpg diesel v 140ppl @ 35mpg petrol over 1000 miles would be 101L used for diesel @ £151.52 v 129L used for petrol @ £181.33
You're right. I should have added on that Diesel cars are more expensive to buy in the first place. Lets pick a ball park figure of 2K (Audi A3 35 TDI vs 35 TFSI as an example)150ppl @ 45mpg diesel v 140ppl @ 35mpg petrol over 1000 miles would be 101L used for diesel @ £151.52 v 129L used for petrol @ £181.33
So you need to drive thousands of miles to offset that fuel saving. My quick maths suggest 66K at £30 saved per 1000miles
I have a 10 year old Freelander 2 diesel, still with its dpf intact, never caused an issue and have never even noticed it doing a regen. It's nearly at 120k miles. Hoping to have a diesel for a long time to come.
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