D3s and Diesel Particulate Filters

[Builder22]

Hey there,

This might be an odd question but for the guys that have diesel D3s, do you know if those cars have diesel particulate filters fitted. Not sure how of an issue this is, but I’ve heard that modern diesel cars (circa 2008, Euro 5 compliant) have these filters installed, so help reduce emissions etc.

My wife drives a 2008 Nissan x-trail and there appears to be an inherent problem where these filters get clogged up. And the suggested approach for unclogging them doesn’t always work i.e. drive @ approx 50MPH for 30 minutes to burn off the material. Apparently is it not limited to Nissans, as other makes (Ford and others) are reporting the issue too.

Additionally EU regs mean that the sulphur content in diesel fuels have been dropped way down or eliminated altogether and this apparently is also causing issues with clogged injectors and other failures for engines where these filters are being used.

An informal suggestion by one of the service guys was to use some 2-stroke oil with the diesel fuel mix and this would help prevent the issue.

I’m wondering if anyone with a D3 has encountered any problems related to this, or could this simply be an urban legend. So over to the folks that know…

B

[PsYcHe]

Dont know about D3s specifically, but that is a known issue with DPFs. Especially if you do a lot of town driving/short journeys.

Can work out expensive if the filter clogs too

[mikael]

I have a 2006 4.2 TDI. The 4.2 TDIs all came fitted as standard with 2 DPFs. My car has now done nearly 70k miles and I have never had any problems. I do however regularly undertake long runs, so the filters would get a chance to burn of their soot. I have heard of problems with A3s that are used on short runs equipped with DPFs. However, in general the Audi ones seem much better than those made by other manufacturers.

I have heard BT had lots of problems with Vauxhall vans equipped with them. However as far as I know, the Vauxhall ones work with an ammonia additive, whereas the Audi ones use a more sophisticated construction that works without additives. It could be that other manufacturers have more problems than Audi/VW for this reason.

A friend of mine has a Ford focus used for long distance motorway cruising, and he too has had trouble with the DPF on it, so they can go wrong on cars even if they are only used for long trips.

[Builder22]

Thanks for the response guys,

Kinda makes you wonder if the DPFs were a short cut to reduced emissions but without thinking it through about the long term implications.

Some of the defensive manufacturer comments I’ve heard include, well you know that car is not suitable for city driving and should only be used for long distance driving. Well considering that my daily it does approx 60 mile round trip 80% to 90% of which would be at 70 ish MPH. Therefore I don’t think that argument stacks up.

Cars should be fit for purpose, but many of the manufactures appear to be washing their hands of the problem. Nissan have said that they will do one re-generation cycle under warranty however further ones will not be covered.

Re-generation cycle is the name given to the process where they force the car to burn off the excess soot. Unfortunately a by-product of this process involves flooding the engine with fuel, resulting in the engine oil becoming contaminated, and this having to be changed out, and the stuff is not cheap and there is a considerable labour charge to do this too.

I was thinking that at some point I would move to a diesel D3 but if they are going to potentially suffer from the same problem it kinda makes me think about the practicalities of any big engine diesel car. I may just “have” to make do with a petrol A/S8 in the future.

[mikael]

It sounds like with your driving you would be 100% fine with a diesel A8. If you are that concerned, you could however make sure you get an A8 3.0 TDI SWB. Even the facelifed ones did not have the DPF as standard. Only the LWB ones did. Pre 2008 only the 4.2 TDI A8 had DPFs as standard anyway I think.

[cruiser647]

Would the old Miller's Diesel+ stuff help at all?

Opie Oil man sells the stuff.......