DPF Again

[ozzkev]

Hi guys well aim going to post this thread again about the Navara D40 Auto with DPF 's ... I have been doing quite a bit looking around about this topic and have been reading some very interesting articles in regards to this, I am looking At removing mine as what the long term problems that it can cause firstly I have questions I have asked Nissan with still no replies as yet ..
1 Why were they only ever fitted to an auto and the manual didn't have it ? It is still a diesel ..
2 Without the DPF the engine can use a good quality engine oil ... Such as Penrite etc which I personally know is better for the engine in general.
3 I have read some very interesting articles in the states (USA) and what they have found in the long term what damage they can cause for example
As we all know the excessive fuel usage ... And interesting enough some diesel can find it's way into the sump, now funnier enough I have experienced this with mine when I bought mine it was coming due for a oil change, the oil was say the least not very good it stained everything even my skin etc as if it diesel in it ... Once changing the oil (low ash of course) it has been fine since none of this staining as it was, and not to mention it can have an effect on the turbo apparently.
4 When I mention replacing here once before I had some people say it's illegal to do so as far emissions are concerned ... Well yes to a certain degree .... But if it was good for "Emissions" etc why has Nissan stopped using it in the autos ... So how can it make it illegal I'm wondering
5 Old school thinking of diesel engines .... One of the worst things a diesel hates is restriction.... Which a DPF does .. It restricts flow that's why when removed it gains performance and economy ie: "No restrictions... And even flow so to speak"

Lastly I'd like to here from anyone that has removed the DPF as well blanking the ERG and the results they have achieved by doing so anyway enough from me be interesting to hear your thoughts

Cheers Kev

 

[Old.Tony]

There must be something in driving styles that makes it different for each of us. If I could gain an extra litre per hundred km by removing my DPF I'd be able to get mine sub-10s!

I don't know why they added them only to the autos, perhaps it was a way of introducing the technology. Perhaps it was because the autos - which tend to use more fuel - needed a little extra to reduce emissions. They seem to have overcome that by better tuning.

The legality of it is really a non-issue. Yes it's illegal, but that's because you are not allowed to alter, remove, bypass or negate any emission control device fitted to the vehicle. The fine was $13,200 (might have changed, I can't be bothered looking through Austlii to see) but you have to be caught - and that would take a fairly intensive inspection of the vehicle, by someone who specifically knew that those particular models of Navara had a DPF in the first place.

As for being restrictive - no argument there, it must be. Whether it is making a HUGE difference or not I can't say, mine is still intact and I can't say I'm unhappy with the performance - or the economy, for that matter.

Oh, Penrite do make a fully synthetic low-ash formula oil that is suitable for DPF-fitted engines, I am pretty sure someone here uses it. Penrite should have a chart of suitability - if not on their website, mechanics that use it should have the chart and can readily look up the make & model and tell you if the oil is ok. The main criteria is that the oil is low ash formula (so it doesn't block the DPF) and it should meet or exceed JASO-FD (API-C4 I think is the equivalent).

The last thing I'm curious about is the "diesel in the sump" problem you've raised. There's no path that leads from the fuel injectors into the sump. There's a path from the sump into the intake (PCV) but not the other way around. Once injected, the fuel is combusted, enters the exhaust manifold, passes through the turbocharger into the DPF, down to the CAT and out the back. Exhaust gasses passing from the EGR into the intake manifold again don't flow into the sump, so an over-fuelling shouldn't end up spilling into the crankcase oil.

So the question is, how does the diesel get in there?

 

[Krankin]

2 Without the DPF the engine can use a good quality engine oil ... Such as Penrite etc which I personally know is better for the engine in general.


Cheers Kev

Dont know where you got that info from....

There's absolutely nothing wrong with the engine oil grades made for use with DPF's, in fact they are top quality

maybe the DPF's are shite, but certainly not the oil qualities

 

[180degrees]

whats the fine for removing the DPF if you get caught? like $20000 or something?

you could always sidegrade to an older D40 without the DPF if it bothers you that much.

 

[Krankin]

whats the fine for removing the DPF if you get caught? like $20000 or something?

you could always sidegrade to an older D40 without the DPF if it bothers you that much.

older OR newer...or a manual


but then again......a D22..

 

[JPMC]

The latest facelift D40's about to be released in Europe are needing to pass Euro 5 specs and are getting DPF's for both auto and manual models to do so.
Needless to say the guy's over there aren't to happy about it.