DPF Causing problems with daily driving

Automatic diesel pajero owners have had a similar problem for a while.

Some resorted to taking it o the dealer and getting the dealer to enter a code to force the DPF to clean.

From what I have read it takes about 20k of running for the clean to happen.

Tony...I believe you are spot on and that these DPFs are causing excessive fuel consumption in a few STX Navaras and any of the modern vehicles using them.

They basically operate by having the ECM over fuel for a short period...this causes excess EGT and that heats the catalyst and enables the burn off of trapped particulate.

As you said the problem is if the ECM does a burn and the vehicle is shut down the burn never occurs.

I think it will be an ongoing problem that is more prevalent the more the manufacturers use this method to control emissions. Although the other option is exhaust additives like urea injection (Addblue) and unless you are in a transport company it would be a PITA filling up another tank!!

In the meantime...ie before a long trip it might assist in modifying driving style. Nothing personal but the trend is to drive these like they are petrol engines and that on-off style contributes greatly to excessive emissions and particulate.

Unfortunately(?) they do drive with the same get and go as petrol engines and hence they are driven like that but it is far from what a diesel was ever designed to do.

You are not alone and I think there will be more and more voicing their concerns as you are.

All the best
Matt

considering you did so much research on your vehicle its funny you managed to miss what Isuzu call 'the most significant addiition'.

your guru

Maximus Wankerius

http://www.youtube.com/watch?v=1XcKDTwXheA

I would like to thank you all for you responses to what it would seem has been a problem for some vehicles and maybe not others. I think i may not have been very clear on my query though. I am not having a problem as yet, the purpose of my thread was to see if anyone has had general issues with modern diesels so i know a) what to look for if i do have a problem and b) how to combat it.

Something i have found out which was recommended to someone by a dealer was a regular run at over 70Kph for 30 minutes. Now this was for a new Suzuki Grande Vitara diesel, however i suspect similar treatment would combat it in most new diesels.

Thanks again everyone.

Tony

As stated before the latest Pajeros have the same issue. I believe it has largely been cured by a firmware update to the ECU by Mitsubishi. It was a common issue on the Paj forum when they first came out but no-one seems to mention it anymore.
Maybe Nissan will eventually do the same..

Tony, there may be another issue here that causes excessive fuel consumption:

Excessive fuel consumption can also be incurred just by excessive idling (ie. stuck in trraffic or at traffic lights) in many of the new diesels that are designed to meet strict Euro emission standards...

I work for a coach company and when they took delivery of a couple of new Volvo B12B coaches, all the drivers were instructed not to leave them idling unless absolutely necessary. If you were to be waiting more than a few minutes at any time, shut down the engine and restart it when required. The reasons given were as follows:
It is because the Euro standards require the 'nasties' to be measured in parts-per-million (ppm) basically stating that the number of 'nasty' particles can't exceed X No. ppm. When the engine is idling, it really isn't running efficiently (just enough to keep it turning over) mainly because it's tuned for running at higher speeds (ie. driving it!). So there are two problems...
1/ The easiest way to reduce the number of nasty particles (when measured in ppm) is to just INCREASE everything else, and therefore reduce the ratio. To do that, you have to pour more fuel through the system.
2/ The engine actually cools at idle (because it's not working as hard) and this also causes it to run less efficiently. Therefore, the ECM goes into a 'heating' mode where it puts more fuel into the engine to maintain the ideal engine temperature.
Isn't it ironic how these Euro emissions standards are supposed to "help the environment", instead they just cause every diesel engine to be designed to use more fuel (at idle)?

Besides that, (and relating more to your original question) most cars don't like frequent short runs where they never really reach full operating temperature, especially not diesels (which take longer to reach full operating temperature anyway) - they are great for long runs, but not especially suited to frequent short trips in the city.

Update: It would seem that DPF's are a bit of an unknown quantity. I have now spoken with 2 Isuzu Ute service depts and a young fella at Total Care 4WD (Jason wasn't available) and none of them could really give me much info on this. Isuzu didn't seem to think it would cause any issue at all as long as the vehicle is serviced regularly and i don't use bio-diesel (huh?) and Total Care thought i was talking about the fuel filter until i explained where it is and what its meant to do and then the answer was they haven't heard of any issues.

So, either a)it isn't a problem or b) it is and no one wants to own up to it. Things i have learnt:

Never use bio-diesel (i am sure the greenies will love that one)
If using for off-road use, service more regularly than the posted 10K
Be aware of Summer vs Winter Diesel (and how am i supposed to know that?)
Regularly take vehicle on hwy speed runs to let the DPF regenerate properly
Stop worrying about things that may never cause a problem.

Tony.

Another update for anyone interested.

Right now i am very impressed with the Gosford Isuzu Ute Service Dept. Luke from there just gave me a call. Earlier today i left a message for him to call me regarding this matter, after i didnt here from him i had givenm up. However, it turns out he sent an email to Japan Isuzu asking for information. The reply was that the Isuzu DMAX readily complies with the current Euro standard on ommisions and therefore there was no requirement for them to put a DPF on the vehicle exhaust system.

So i am now an even happier Isuzu DMAX owner as A) i dont have to worry about DPF concerns, B) if i want to do minor mods later on i wont have to take that in consideration and C) i can use, according to the service manager, 15W40 oil when i do my changes, which may save a little money.

Everyone, thank you again for all your responses. As always, exploroz community has come together to try and help a fellow enthusiast. Thanks guys.

Tony