DPFs. More hassle than they're worth?
Discussion
heebeegeetee said:
Now this is so untrue so why say it?
Unless it's been done very badly, a car with a dpf removed will go through it's MOT year after year, and if you're thinking of roadside checks, the odds are so minimal you wouldn't be able to express the odds.
It is NOT an easy way to get slapped with a big fine, you have simply made that up.
For now - huge pressure on the government to tighten up the checks and stamp out emissions circumvention. I'm not sure how, but it seems an easy target considering how prevalent it is. Unless it's been done very badly, a car with a dpf removed will go through it's MOT year after year, and if you're thinking of roadside checks, the odds are so minimal you wouldn't be able to express the odds.
It is NOT an easy way to get slapped with a big fine, you have simply made that up.
For any post about issues on diesel cars, you get some muppet extoling the virtues of a DPF delete (or on petrols, ripping gout the EGR/swirl flaps)
guitarcarfanatic said:
For now - huge pressure on the government to tighten up the checks and stamp out emissions circumvention. I'm not sure how, but it seems an easy target considering how prevalent it is.
For any post about issues on diesel cars, you get some muppet extoling the virtues of a DPF delete (or on petrols, ripping gout the EGR/swirl flaps)
In Europe they have been rolling out optical particle monitoring as part of the mot equivalent. We will no doubt follow at some point.For any post about issues on diesel cars, you get some muppet extoling the virtues of a DPF delete (or on petrols, ripping gout the EGR/swirl flaps)
There is a lack of knowledge about how to repair the faults that cause the car not to regenerate, which is not surprising when manufacturers software will happily tell you that the DPF is full and ‘conditions are not right for regeneration’ but not give any details why!
Made worse by some manufacturers linking seemingly unconnected systems to necessary regeneration conditions. Outside air temperature sensors, faulty thermostats, glow plugs even aircon not working (some Hondas used to engage the aircon to load the engine for regens).
It’s not surprising that the repair industry has trouble fixing them when the manufacturers are not providing enough fault detail in software tools and technical bulletins.
LordLoveLength said:
In Europe they have been rolling out optical particle monitoring as part of the mot equivalent. We will no doubt follow at some point.
Just read they started trialling in the UK last year across 10 stations. Seems like on the cards to be standard in the foreseeable 
Little Pete said:
heebeegeetee said:
Now this is so untrue so why say it?
Unless it's been done very badly, a car with a dpf removed will go through it's MOT year after year, and if you're thinking of roadside checks, the odds are so minimal you wouldn't be able to express the odds.
It is NOT an easy way to get slapped with a big fine, you have simply made that up.
Morals? We're petrolheads, so forget that. We drive for pleasure; we buy lots of cars; we run old cars; we participate or follow Motorsport, and it doesn't get more polluting than that imo. I mean, I even have a (diesel driving) friend who flies round the world photographing Motorsport, then comes home and posts crap on Facebook about EVs.
There could have been occasions where I have passed a vehicle that has had a DPF delete, I suppose if there is no physical difference I wouldn't know.Unless it's been done very badly, a car with a dpf removed will go through it's MOT year after year, and if you're thinking of roadside checks, the odds are so minimal you wouldn't be able to express the odds.
It is NOT an easy way to get slapped with a big fine, you have simply made that up.
Morals? We're petrolheads, so forget that. We drive for pleasure; we buy lots of cars; we run old cars; we participate or follow Motorsport, and it doesn't get more polluting than that imo. I mean, I even have a (diesel driving) friend who flies round the world photographing Motorsport, then comes home and posts crap on Facebook about EVs.
I have however failed quite a few on the emissions where the DPF has had the middle removed and has had the delete. I did an emissions test on a Mercedes Sprinter last week for someone in the trade who told me this had been done and the emissions were nowhere near low enough to pass. DPFs are extremely efficient at keeping soot levels low.
The owner of the MOT garage next to us had the opinion that DPFs are legalised fly tipping, whereby you drive round town saving up your sh*t then you drive into the countryside and dump it. In other words, not every MOT tester is on side with the aims of the legislation.
I learnt on my particular car that if the dpf light came on, the best thing I could do was to just keep driving until it went out. This resulted in me often having to cancel whatever it was that I was going to do, and just kept driving instead. The A38 towards Burton and Derby was my favourite route for this (I live in Sutton Coldfield).
On the one occasion when I had no choice but to join crawling traffic, the engine light came on and functions such as cruise no longer functioned. So I had a forced regen carried out.
What an absolutely ridiculous process that is. The car sits at about 4k rpm and gets absolutely sticking hot, for about 20-30 mins. Two attempts failed, then my guy suddenly remembered he had some different diagnostic kit on appro. That was able to tell car's ECU that the dpf had been replaced, and out went the engine light.
That sorted everything out and I was good to go. I got the dpf deleted after that. It was about 6 years ago and I've never had a problem on MOT. Car now has 172k miles on it.
guitarcarfanatic said:
LordLoveLength said:
In Europe they have been rolling out optical particle monitoring as part of the mot equivalent. We will no doubt follow at some point.
Just read they started trialling in the UK last year across 10 stations. Seems like on the cards to be standard in the foreseeable guitarcarfanatic said:
Just read they started trialling in the UK last year across 10 stations. Seems like on the cards to be standard in the foreseeable
The SI unit of (diesel l) smoke is the HSU the Hartridge Smoke unit. Which uses a calibrated light through the smoke passing down a fixed length tube. Hartridge, was based in Buckingham making mainly desisel calibration test rigs and smoke metering units. and in the 80s and 90s was owned by Lucas Industries Plc (later Lucas Varity, then Varity perkins, and later cut up and shared out between TRW and UTC) I still have a couple of business cards from engineers at Lucas Hartridge Ltd following a Design for Manufacture Workshop I participated on in about 1993 on their Smoke metering machine, which had too many components.
Scottie - NW said:
guitarcarfanatic said:
LordLoveLength said:
In Europe they have been rolling out optical particle monitoring as part of the mot equivalent. We will no doubt follow at some point.
Just read they started trialling in the UK last year across 10 stations. Seems like on the cards to be standard in the foreseeable heebeegeetee said:
Thing is, some places removing DPFs are also doing MOTs as well.
The owner of the MOT garage next to us had the opinion that DPFs are legalised fly tipping, whereby you drive round town saving up your sh*t then you drive into the countryside and dump it. In other words, not every MOT tester is on side with the aims of the legislation.
I learnt on my particular car that if the dpf light came on, the best thing I could do was to just keep driving until it went out. This resulted in me often having to cancel whatever it was that I was going to do, and just kept driving instead. The A38 towards Burton and Derby was my favourite route for this (I live in Sutton Coldfield).
On the one occasion when I had no choice but to join crawling traffic, the engine light came on and functions such as cruise no longer functioned. So I had a forced regen carried out.
What an absolutely ridiculous process that is. The car sits at about 4k rpm and gets absolutely sticking hot, for about 20-30 mins. Two attempts failed, then my guy suddenly remembered he had some different diagnostic kit on appro. That was able to tell car's ECU that the dpf had been replaced, and out went the engine light.
That sorted everything out and I was good to go. I got the dpf deleted after that. It was about 6 years ago and I've never had a problem on MOT. Car now has 172k miles on it.
I know, there is one near me. He did a delete on a VW Crafter a couple of years ago and I failed it on emissions. It came back a few days later with the value on the vin plate scratched off so I had to retest it to the higher default limit. It still failed. I saw the van on the road some time later so I looked at its MOT history and it had passed two days after the failed retest. I still see the van around town and the rear doors are covered in soot. We don’t, or shouldn’t, get to cherry pick the bits of the manual we agree with and ignore the bits we don’t. The owner of the MOT garage next to us had the opinion that DPFs are legalised fly tipping, whereby you drive round town saving up your sh*t then you drive into the countryside and dump it. In other words, not every MOT tester is on side with the aims of the legislation.
I learnt on my particular car that if the dpf light came on, the best thing I could do was to just keep driving until it went out. This resulted in me often having to cancel whatever it was that I was going to do, and just kept driving instead. The A38 towards Burton and Derby was my favourite route for this (I live in Sutton Coldfield).
On the one occasion when I had no choice but to join crawling traffic, the engine light came on and functions such as cruise no longer functioned. So I had a forced regen carried out.
What an absolutely ridiculous process that is. The car sits at about 4k rpm and gets absolutely sticking hot, for about 20-30 mins. Two attempts failed, then my guy suddenly remembered he had some different diagnostic kit on appro. That was able to tell car's ECU that the dpf had been replaced, and out went the engine light.
That sorted everything out and I was good to go. I got the dpf deleted after that. It was about 6 years ago and I've never had a problem on MOT. Car now has 172k miles on it.
Little Pete said:
I know, there is one near me. He did a delete on a VW Crafter a couple of years ago and I failed it on emissions. It came back a few days later with the value on the vin plate scratched off so I had to retest it to the higher default limit. It still failed. I saw the van on the road some time later so I looked at its MOT history and it had passed two days after the failed retest. I still see the van around town and the rear doors are covered in soot. We don’t, or shouldn’t, get to cherry pick the bits of the manual we agree with and ignore the bits we don’t.
If the rear doors are covered in soot it's not just because of dpf delete, is it? guitarcarfanatic said:
For now - huge pressure on the government to tighten up the checks and stamp out emissions circumvention. I'm not sure how, but it seems an easy target considering how prevalent it is.
For any post about issues on diesel cars, you get some muppet extoling the virtues of a DPF delete (or on petrols, ripping gout the EGR/swirl flaps)
Just to reiterate - 8 weeks ago wife and I were stranded in France for one week after the adblue system on our 26 months-old motorhome failed. Cost was 1800 euros plus one week's accommodation. For any post about issues on diesel cars, you get some muppet extoling the virtues of a DPF delete (or on petrols, ripping gout the EGR/swirl flaps)
I think I'd be a muppet to let that happen again. I think the muppets are those who believe these systems actually reduce emissions - they don't, they simply allow vehicles to pass tests.
Scottie - NW said:
They can roll out as many tests as they like for the mot test but they are still all negated by simply putting the sensor into the exhaust pipe of a different car parked next to it!!
If you don’t mind being fraudulent, sure. Might as well look at the tyres and brakes on another vehicle while you’re at it, hey?My frustration with the automotive industry is that they should recognise the issues with dpf, egr, ad blue, etc and at the very least, design them to be easily serviceable.
It being a 10 minute job to remove an egr / dpf and run it through a cleaner as part of an annual service would help immensely. Instead getting an egr out is a total PITA.
It being a 10 minute job to remove an egr / dpf and run it through a cleaner as part of an annual service would help immensely. Instead getting an egr out is a total PITA.
Fusion777 said:
Scottie - NW said:
They can roll out as many tests as they like for the mot test but they are still all negated by simply putting the sensor into the exhaust pipe of a different car parked next to it!!
If you don’t mind being fraudulent, sure. Might as well look at the tyres and brakes on another vehicle while you’re at it, hey?But not on a car that has already logged a couple of fails.
My biggest surprise was the amount of stuff that gets missed; it's embarrassing having to phone a customer to tell them their car has passed it's MOT but now we're servicing it we've found a broken spring.
heebeegeetee said:
If the rear doors are covered in soot it's not just because of dpf delete, is it?
Clearly not, there will be an underlying problem that caused the DPF to block in the first place. Just fix the problem, clean the filter and reset, as you did with yours. If everyone just bypassed the faults and bodged the system we would be back to the levels of pollution we used to have from vehicles, buses and trucks in particular. heebeegeetee said:
Just to reiterate - 8 weeks ago wife and I were stranded in France for one week after the adblue system on our 26 months-old motorhome failed. Cost was 1800 euros plus one week's accommodation.
I think I'd be a muppet to let that happen again. I think the muppets are those who believe these systems actually reduce emissions - they don't, they simply allow vehicles to pass tests.
Yeah the issues with adblue tanks and pumps is a big one. We look after a lot of motorhomes and school minibuses and the amount we have changed is embarrassing. They are just not designed for low usage vehicles. I think I'd be a muppet to let that happen again. I think the muppets are those who believe these systems actually reduce emissions - they don't, they simply allow vehicles to pass tests.
I disagree about the systems not lowering emissions though. I would say that around two thirds of the diesels we test don’t even generate a reading on the machine, and the inside of the tailpipe is spotlessly clean.
Edited by Little Pete on Tuesday 9th April 08:33
Little Pete said:
I know, there is one near me. He did a delete on a VW Crafter a couple of years ago and I failed it on emissions. It came back a few days later with the value on the vin plate scratched off so I had to retest it to the higher default limit. It still failed. I saw the van on the road some time later so I looked at its MOT history and it had passed two days after the failed retest.
.....
This was always a concern on a 2005 Merc I had, that didn't have a dpf. I understood that once the plate value had been recorded at MOT then that was used for future MOTs?.....
Mine seemed to have a value on the VIN plate but testers ignored it. The default value was 3, but some used 1.5 and it passed that. The plate value was 0.9 (the number was inside two squares?). I don't know how hard it would have been to get through that.
Little Pete said:
I would say that around two thirds of the diesels we test don’t even generate a reading on the machine, and the inside of the tailpipe is spotlessly clean.
That's good to hear, but I was referring to overall emissions.Edited by Little Pete on Tuesday 9th April 08:33
Take my old diesel as an example, When it went through that ridiculous forced regen process (not to mention all the extra miles I drove until a regen process completed), did that counteract the savings made by the dpf over the years? I can't see how we can know.
Re yours and my experience with adblue, regarding the vehicles that have suffered a failure, I think we can safely say those vehicles will be in negative emissions equity for a long time.
TGCOTF-dewey said:
My frustration with the automotive industry is that they should recognise the issues with dpf, egr, ad blue, etc and at the very least, design them to be easily serviceable.
It being a 10 minute job to remove an egr / dpf and run it through a cleaner as part of an annual service would help immensely. Instead getting an egr out is a total PITA.
The point is, the system shouldn't need to be touched. They are generally robust, but problems elsewhere lead to DPF issues. And rather than solving the underlying problem, too often the DPF get's the blame and gets ripped out. It being a 10 minute job to remove an egr / dpf and run it through a cleaner as part of an annual service would help immensely. Instead getting an egr out is a total PITA.
Sheepshanks said:
Little Pete said:
I know, there is one near me. He did a delete on a VW Crafter a couple of years ago and I failed it on emissions. It came back a few days later with the value on the vin plate scratched off so I had to retest it to the higher default limit. It still failed. I saw the van on the road some time later so I looked at its MOT history and it had passed two days after the failed retest.
.....
This was always a concern on a 2005 Merc I had, that didn't have a dpf. I understood that once the plate value had been recorded at MOT then that was used for future MOTs?.....
Mine seemed to have a value on the VIN plate but testers ignored it. The default value was 3, but some used 1.5 and it passed that. The plate value was 0.9 (the number was inside two squares?). I don't know how hard it would have been to get through that.
LordLoveLength said:
In Europe they have been rolling out optical particle monitoring as part of the mot equivalent. We will no doubt follow at some point.
There is a lack of knowledge about how to repair the faults that cause the car not to regenerate, which is not surprising when manufacturers software will happily tell you that the DPF is full and ‘conditions are not right for regeneration’ but not give any details why!
Made worse by some manufacturers linking seemingly unconnected systems to necessary regeneration conditions. Outside air temperature sensors, faulty thermostats, glow plugs even aircon not working (some Hondas used to engage the aircon to load the engine for regens).
It’s not surprising that the repair industry has trouble fixing them when the manufacturers are not providing enough fault detail in software tools and technical bulletins.
I have seen optical particle measurements cameras in the news. To think you can measure exhaust particle, and attribute it to a particular car with a glorified CCTV is just comically. There is a lack of knowledge about how to repair the faults that cause the car not to regenerate, which is not surprising when manufacturers software will happily tell you that the DPF is full and ‘conditions are not right for regeneration’ but not give any details why!
Made worse by some manufacturers linking seemingly unconnected systems to necessary regeneration conditions. Outside air temperature sensors, faulty thermostats, glow plugs even aircon not working (some Hondas used to engage the aircon to load the engine for regens).
It’s not surprising that the repair industry has trouble fixing them when the manufacturers are not providing enough fault detail in software tools and technical bulletins.
The exhaust gas analysers to measure to certification levels are hundreds of thousands of pounds, and from EU stage 6 the particulate is done by count, not weight.
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