DPFs. More hassle than they're worth?

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?

Likely to be a faulty pressure sensor - common on VAG group cars. Find the faulty sensor, replace and do a force regen and should hopefully be good.

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.

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).

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?

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Diesel in general is a fine fuel for a specific purpose. And that purpose is NOT a passenger car! laugh
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10 years in, average 60 mpg
£35 annual tax
0 Dpf errors

You absolute loon

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.

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

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!

Well as you've managed that, then that's absolutely true for every diesel driver isn't it! There are ZERO problems for everyone with any diesel car and its emissions systems

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)

So you need to drive thousands of miles to offset that fuel saving. My quick maths suggest 66K at £30 saved per 1000miles

Smugly, sits back into armchair to breathe in a huge amount of carbon monoxide

“Take that Greta Thunberg”