DPF issue

tumasgts · Post by **tumasgts** » Wed Dec 31, 2014 6:57 am

Morning! This is the third time I got a system fault in relation to DPF.. This is starting to get on my nerves going to the dealership and doing a regen. This QQ has been at me since March and I don't really think this should happen this often.. Anyone knows if there is a form of bypass or maybe something I can do to reduce this happening? Also what is the optimum revs and speed one should drive to start the regen process?

F1 Bob · Post by **F1 Bob** » Wed Dec 31, 2014 8:17 am

There is no bypass that is legal for the DPF fitted to new cars. I believe motorway speeds for 15 to 20 minutes is the minimum to clear the filter but others will know more than I do and I am sure they will post here soon.

tumasgts · Post by **tumasgts** » Wed Dec 31, 2014 8:24 am

Problem is that Malta (tiny island) it takes around 15 mins to cross from one side to another.... roads aren't long enough!

MJCQQ · Post by **MJCQQ** » Wed Dec 31, 2014 8:39 am

It seems very strange that diesel models are even on sale there. Can you not get the dealer to swap it for a petrol? It seems to me the dealer should have known the DPF issue would be a major problem given the size of the island.A mate of mines GF wanted a new A Class Merc. They both live in a city, only have a commute of 3-4 miles per day, and do almost no motorway driving. They could only afford second hand, so when a diesel version became available in their price range he jumped on it. Despite warnings that given their driving style, a diesel with DPF was an atrocious choice.Their nice A class has been back to the dealer 3 times with DPF warning. The dealer did the first regen for free but subsequent ones are chargeable. The dealer is basically taking the stance of "you should have done your research", and has washed their hands of it. The dealers advice was that he should take a 20 minute "rake" up the motorway once or twice a week to clear the DPF. My mate hates me right now because I agree with the dealer.

Kentishman · Post by **Kentishman** » Wed Dec 31, 2014 9:04 am

Please excuse my ignorance but how does a 20 minute run on a motorway clear the dpi people have mentioned temperature but if the engine is running at normal temperature then how does motorway running increase this. I thought the increased airflow would tend to have the opposite effect. Can understand lots of small journeys when engine is not running at optimum temp causing problems, but shouldn't any reasonable journey ar full temp clear it

gvmdaddy · Post by **gvmdaddy** » Wed Dec 31, 2014 9:09 am

I too have the 1.5dci.
3 miles to work, 3 miles back. Shorter trips to the shops. 20 minute blast on motorway once a week, or a good hour on A roads and country lanes...constant run with no stop/start. No problems so far. Had the car since May. Colder temps may make a difference in Winter...we'll just have to see.
Dealer only said that the fuel economy may suffer slightly on low mileage. He actually stated that the dpf would be no problem at all because of the way Nissan get it to self gen whilst driving. I read up on things prior to buying. I spoke to friends, relatives and even a couple of trusted mechanic friends. The only thing they said was to do as I am currently...a good drive once a week. I've made my choice and I'll live with it. It annoys me though when you get people coming on here and telling you you've made the wrong decision...you are wrong and they are right.
I would like Nissan to provide the DCI units with a warning light to tell you the dpf needs a regen BEFORE it goes into limp mode, at least then more people could take preventative measures in time.

jonceebee · Post by **jonceebee** » Wed Dec 31, 2014 9:41 am

As I have mentioned before, my former employers with 40 plus cars will no longer provide diesel cars to anyone who does less than 15k miles per year as they have had continual problems with DPF's.It is a well known fact that these engines are not suitable for day to day town commuting and any decent dealer should always ask what the cars usage will be and push them away from diesel engines on low town driving mileages.When I was working I was often asked if I would take one of the diesel QQ fleet cars and give it a motorway run to clean clogged DPF's but I can say it very rarely if ever worked and a dealer regen was usually necessary. When I bought my QQ in March I wanted a 4 wheel drive, I saw it was diesel only so had to abandon the idea.

tumasgts · Post by **tumasgts** » Wed Dec 31, 2014 9:57 am

Any idea how to get rid of the system error? don't want to take it to the dealership again!

Deleted User 759 · Post by **Deleted User 759** » Wed Dec 31, 2014 10:02 am

There was one person who reported a fault with the ECU/control unit for the DPF in that it was calculating the amount of soot incorrectly. There is a possibility that this it could be a little more widespread than just a one off. Saying that, they needed a software patch (they claimed full re-program but meh, maybe the use of the wrong terminology!)[quote="Kentishman"]]Please excuse my ignorance but how does a 20 minute run on a motorway clear the dpi people have mentioned temperature but if the engine is running at normal temperature then how does motorway running increase this. I thought the increased airflow would tend to have the opposite effect. Can understand lots of small journeys when engine is not running at optimum temp causing problems, but shouldn't any reasonable journey ar full temp clear it [/QUOTE]] My (albeit primitive) understand is the basic principle to clearing out a DPF is to increase the temperature inside the DPF unit to force a catalytic conversion to burn/change the soot into more of an ash substance which is blown out through the exhaust. Some cars use an additive either in the fuel, or sprayed into the DPF, but my understanding is Nissan tweak the fuelling and combustion cycle to generate increased exhaust gas temperatures to induce the catalyst function. Driving to "clear a DPF" should include the normal engine warm up phase (which can take a while in a derv), then when at operational temp the process can begin. This is why motorway runs are ideal as you are at a high speed can punch down a gear or 2 to increase the revs. Yes there is an increase in airflow but its the exhaust gas temperatures that really matter rather than engine block/water temperature. It is claimed that Nissan have overcome the needs for a motorway/high speed blast and could be done in town driving but it still needs time to complete so a 15 minute run may not be enough to get the block up to temperature let alone to start DPF cleaning. It does sound like a bad move for Nissan selling such a car in locations where getting the car up to temp is more or less impossible on a day to day drive![quote="tumasgts"]]Any idea how to get rid of the system error? don't want to take it to the dealership again![/QUOTE]]
Depends on the error. I am not too familiar with the errors for DPF regen, however I understand there is a warning when it tells the driver you need to give it a good drive, and then there is a "you need to take me to a dealer straight away" warning. somebody maybe along to give you guidance on this, but if you have your handbook to hand its noted in there as to what the particular lights mean.

Deleted User 759 · Post by **Deleted User 759** » Wed Dec 31, 2014 10:04 am

[quote="gvmdaddy"]I would like Nissan to provide the DCI units with a warning light to tell you the dpf needs a regen BEFORE it goes into limp mode, at least then more people could take preventative measures in time.[/QUOTE]
Oh, this may have answered your question! This suggests that one the DPF light comes on, its a trip to the dealer rather giving you advanced warning that it needs a good drive

DPF issue

Nissan Qashqai Forums

Follow Nissan QashQai Forums