DPF Causing problems with daily driving

Submitted: Thursday, Jul 02, 2009 at 19:53
ThreadID: 70335 Views:9304 Replies:8 FollowUps:11
This Thread has been Archived
Hi guys, as some of you know, i recently purchased, after much research, a new Isuzu D-Max (Former Holden Rodeo) however one thing that didn't come up in my research was DPF's and problems associated with them when the vehicle is used as a daily driver. Apparently it wont regenerate by burning off the excess soot buildup as the vehicle exhaust doesn't get hot enough.

So, has anyone heard of this problem, what are the risks and how, apart from regular highway runs can i stop this from happening?

Thanks in advance guru's,

Back Expand Un-Read 0 Moderator

Reply By: Member - Oldplodder (QLD) - Thursday, Jul 02, 2009 at 20:15

Thursday, Jul 02, 2009 at 20:15
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.
AnswerID: 372805

Reply By: Member - Matt (Perth-WA) - Thursday, Jul 02, 2009 at 20:26

Thursday, Jul 02, 2009 at 20:26
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
AnswerID: 372812

Follow Up By: Member - TonBon (NSW) - Thursday, Jul 02, 2009 at 20:40

Thursday, Jul 02, 2009 at 20:40

great response, thank you. Its interesting you mention driving style, and no i dont take it personally. My father actually drives long distance trucks for a living and consequently i have been around diesel engines most of my life and while this is the first diesel i have owned, i have modified my driving technique significantly. For example, i have made a conscious effort to listen and feel the truck as i drive and subsequently my gear changes are at around the 2k rev mark. This, i hope, reduces stress on the engine as well as maintains excellent fuel consumption (currently averaging 8Lt per 100Km) when driving around town. Ironically, part of my train of thought was is this rather conservative driving style contributing to the problem the DPF may cause.

i am going to research this further, starting with Isuzu and working from there and i will be sure to post what i find.

Thanks again, Tony

P.S. I see in your picture you have an R9 i think Rodeo :-)
FollowupID: 640067

Follow Up By: Member - Matt (Perth-WA) - Thursday, Jul 02, 2009 at 20:56

Thursday, Jul 02, 2009 at 20:56
Yes Tony Im rather partial to the Isuzus..they are just robust and reliable and I cant ask for more. I really enjoy driving the Rodeo, but know I can fix anything that is thrown my way with it also.

We are a two Isuzu family, wife has a MU and I retained alot of the good gear from my old MU and put it into the Rodeo when I traded.

Stick with it mate...Im sure the manufacturers will get onto the DPF issue in the future. If what we suspect it unacceptable performance they will eventually get around to investigating and csolving the issue. They are only new in this market and everything has to adjust over time.

Look forward to hearing how you go.

All the best

FollowupID: 640072

Follow Up By: Madfisher - Thursday, Jul 02, 2009 at 21:16

Thursday, Jul 02, 2009 at 21:16
Little off topic matt,
but it must be an isuzu thing, I have a 98 se Jack and my wife has and 03 Nullarbor.
Cheers Pete
FollowupID: 640079

Follow Up By: tim_c - Friday, Jul 03, 2009 at 11:13

Friday, Jul 03, 2009 at 11:13
:) Count me into that club too! But I doubt we would ever reach the cult-like status of the Land Rover fans!
FollowupID: 640147

Follow Up By: Member - TonBon (NSW) - Friday, Jul 03, 2009 at 11:31

Friday, Jul 03, 2009 at 11:31
Apologies for getting OT but....Isuzu owners unite :-)

i wouldn't be so sure about that Tim, i am sure Matt and his SWMBO would be hard pressed to part with their respective vehicles and i defy any Landy (all respect) owner to love their vehicle more than i love my DMAX. She is at home in the bush and i am at home in her cabin :-)
FollowupID: 640151

Reply By: drizl1 - Thursday, Jul 02, 2009 at 21:42

Thursday, Jul 02, 2009 at 21:42
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

AnswerID: 372831

Follow Up By: marq - Thursday, Jul 02, 2009 at 21:50

Thursday, Jul 02, 2009 at 21:50
Don't you like things they add to increase fuel use...
FollowupID: 640085

Follow Up By: Member - TonBon (NSW) - Thursday, Jul 02, 2009 at 22:36

Thursday, Jul 02, 2009 at 22:36
Thats a fair point, i am pretty thorough when it comes to researching products i am about to spend a bucket load of money on for a particular purpose. On saying that, i wasnt researching US specced medium and heavy trucks as the youtube video link you added outlines. The D-Max has neither a manual regeneration button, nor warning lights on the dash if the system becomes clogged. And a reasonable search shows very little if any information on the effects this system has on the D-Max in city driving.
FollowupID: 640100

Follow Up By: Member - Matt (Perth-WA) - Friday, Jul 03, 2009 at 14:55

Friday, Jul 03, 2009 at 14:55
As far as Im aware there are no warning or manual activation on any light vehicles on the market ATM...so apart from the system working in principle like the your tube video...it is slightly different in practice.

The ECM makes all the decisions and the operator has no knowledge of its activation....so you can imagine the ECM overfuelling for a burn but the driver gets to his location and shuts down....MORE contamination and unburnt fuel rather than reducing it.

I would also love to hear a salesman describing htis operation at the Dealership and explaining to every Joe how they operate...not gonna happen.

So as far as research goes....whats the difference....they all are fitted now to most of the makes...so what does research matter. YOU DONT HAVE A CHOICE??

Seems to me your name says it all and you contributed very little to Tonys post...so why bother?


FollowupID: 640170

Follow Up By: drizl1 - Friday, Jul 03, 2009 at 21:07

Friday, Jul 03, 2009 at 21:07
It's funny that all your research didn't even clue you in to the fact that it doesn't have a DPF Tony.

Perth. that's funny too.

FollowupID: 640208

Reply By: Member - TonBon (NSW) - Thursday, Jul 02, 2009 at 22:40

Thursday, Jul 02, 2009 at 22:40
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.

AnswerID: 372846

Reply By: MrBitchi (QLD) - Friday, Jul 03, 2009 at 07:50

Friday, Jul 03, 2009 at 07:50
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..
AnswerID: 372873

Reply By: tim_c - Friday, Jul 03, 2009 at 11:33

Friday, Jul 03, 2009 at 11:33
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.
AnswerID: 372898

Reply By: Member - TonBon (NSW) - Friday, Jul 03, 2009 at 12:14

Friday, Jul 03, 2009 at 12:14
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.

AnswerID: 372902

Follow Up By: Madfisher - Friday, Jul 03, 2009 at 13:19

Friday, Jul 03, 2009 at 13:19
Tony if you want info on this contact an Isuzu truck dealer, they are a lot more up to date with this system. A lot of the ute dealers have only just jioned Isuzu, and are not up to speed. Our Isuzu truck dealer said they where not real interested in selling the utes because of competition from Holden and skinny margins.
Cheers Pete
FollowupID: 640162

Follow Up By: Member - TonBon (NSW) - Friday, Jul 03, 2009 at 16:22

Friday, Jul 03, 2009 at 16:22
Thanks Madfisher, i actually thought of doing that after i posted last post, but then i had a call from Isuzu Ute....see general post reply.
FollowupID: 640173

Reply By: Member - TonBon (NSW) - Friday, Jul 03, 2009 at 16:28

Friday, Jul 03, 2009 at 16:28
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.

AnswerID: 372938

Sponsored Links

Popular Products (13)