DPF issues... Annoying

[Imizz]

Hi all, I'm still having problems with the DPF on my 170 sport passat 2008 PD.
For the past couple of weeks every 2 days the car has been doing the regen process but it still throws up the DPF exhaust light on the dash, so have to do the motorway run..

When the car was in to get the the clutch and DMF done, the mechanic hooked up the VAG machine and checked it, was showing only 5% he cleared it to 0% but then the next day the DPF light came on again and then 1 day later again and today again... if the soot % is low why does this happen???

I have had a new pressure sensor fitted when the coil pack and EML came on about a month ago aswell as a new EGR valve, then later new MAF sensor, also had timing belt changed, also full car service with new fuel filter done too.. (Fuel filter was black, canister was clean, i put the fuel in a bottle, it seemed to have a bit of oil mixed into it..)

What could be the issue, it's really frustrating that the DPF light keeps coming on every second day, even though the regen process is followed as per instructions... I'm also use shell fuel and also Millers fuel additive.. Have also used the Forte DPF treatment too.

The mechanic is waiting for the new DPF software update before he starts checking the rest of the car..

Anyone shed any light please...

[martin1810]

No oil or petrol treatments will help the dpf. DPF problems are hard to sort because it's all ECU software calculations based on the dpf pressure sensor, lambda probe etc. It is possible that the dpf has had it. This does happen. Can you get any engine data via VCDS. That might give a clue.

[fat controller]

Are replacement DPF's likely to become cheaper as the technology becomes more common?

[stublack]

Potentially an option might be to go to a company such as Black Code and have the DPF removed altogether along with suitable adjustments to the ECU?

[MikeM46]

Imizz ... what's your mileage? From a quick look in the service booklet I reckon that at high mileage there's every chance that after successive regens, the remaining ash content in the filter builds up to the point where it is just too much & it's time for a new one & boy are they not cheap.

Did you have the car from new? If not, previous owner may not have had a driving regime best suited to these filters.

[gresty]

Sounds like a similar problem with mine. Although since changing jobs and doing a 30 mile round trip on the motorway instead of short journeys, the dpf warning has not appeared since.
What sort of mileage have you got on your car?

I am still considering dpf removal. It is quite expensive but the problem will never come back and the cost for a new dpf is more expensive than removal.

Dpf's are a bitch in my opinion and should all be removed. All they do is cause problems and eventually clogg up.

[MikeM46]

Sounds like a similar problem with mine. Although since changing jobs and doing a 30 mile round trip on the motorway instead of short journeys, the dpf warning has not appeared since.
What sort of mileage have you got on your car?

I am still considering dpf removal. It is quite expensive but the problem will never come back and the cost for a new dpf is more expensive than removal.

Dpf's are a bitch in my opinion and should all be removed. All they do is cause problems and eventually clogg up.

But is this a MOT test proof option?

[gresty]

At the moment a dpf isn't a testable item. All a dpf does is take way the smoke (soot n stuff) not the emissions (that's the cats job) so technically it don't matter.

[gresty]

And, when the dpf is regenerating on a long run or by itself, it is burning off the soot so creating a smoke by doing so in the process. In theory, it stores the soot, then when it senses it's getting clogged, burns it all, creating smoke which you probably won't see cos your doing 70 mph on the motorway thusly clearing itself.

[MikeM46]

Sorry, but beg to differ!

Diesel engines are subject to a smoke test

http://www.dft.gov.uk/vosa/repositor...sel%20card.pdf

The whole point of the dpf is to mimise smoke emissions from diesel engines & newer cars with dpfs are subject to more stringent minimal smoke levels. This was introduced last year for vehicles first in service from 1 July 2008 on and implemented from 1 July 2011

http://www.dft.gov.uk/vosa/repositor...ce%2003-10.pdf see first part of the update



Now, if you can get the car through the mot without dpf to meet the relevant standard, that's another matter altogether!