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Discussion Starter #1
Has anyone seen/heard of any problems reported with the DPF equipped diesel engine in the latest Accord or CR-V models?
 

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Having read 25 reviews on a Hungarian site no one has ever mentioned DPF problems for the new Accord. Plus mine Accord I-DTEC seems to be problem free as well.
 

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Re DPF problems... not a problem as such but a consequence of Honda's version perhaps. As per Pottsy's post re fuel consumption and the DPF it seems that unless the car is used regularly for longish fast runs (up to 70mph) then fuel economy shows a marked periodic dip by about 3-4mpg for (and this is a bit of a guess) about 44-64 miles or so.

I have a daily round trip of 22 miles on green lanes, B roads and a short stretch of A road, none of which is particularly fast, say up to 60mph for short periods. About once overy 9 travelling days fuel consumption drops markedly into the 43-44mpg rather than 47mpg plus at its best. One way I've found to shorten the period of reduced fuel economy is to drive in a lower gear and try to hit at least 2000rpm on a single journey at least once a week.

I don't know if this is characteristic of other DPF equiped engines, if so then so be it but if peculiar to Honda then you would have to ask why.

Hope this helps.

Regards,
Chris
 

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My uncle has an Idtec accord and only potters about doing short distances at urban speeds - in 6 months he has had no problems
 

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Honda Accord 2,2TDI DPF Problems

Has anyone seen/heard of any problems reported with the DPF equipped diesel engine in the latest Accord or CR-V models?
Hi,
I bought the new Honda Accord 2,2 TDI in December 2009 and soon experienced problems with DPF.
After cca.700-800 km driving exclusively in town there appeared the message "DPF regeneration required".I ignored that symbol ( at that time didn't know what DPF is) and soon "DPF Check System" appeared and I went to Honda service. They cleaned DPF filter.
After that I drove my Honda out of the town too and everything was OK till September 2010. Then again, after cca. 700 km exclusively in the town message apeared - but without warning -> immediately "DPF Check System". Again Honda service...
 

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Dr. Evil
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Re DPF problems... not a problem as such but a consequence of Honda's version perhaps. As per Pottsy's post re fuel consumption and the DPF it seems that unless the car is used regularly for longish fast runs (up to 70mph) then fuel economy shows a marked periodic dip by about 3-4mpg for (and this is a bit of a guess) about 44-64 miles or so.

I have a daily round trip of 22 miles on green lanes, B roads and a short stretch of A road, none of which is particularly fast, say up to 60mph for short periods. About once overy 9 travelling days fuel consumption drops markedly into the 43-44mpg rather than 47mpg plus at its best. One way I've found to shorten the period of reduced fuel economy is to drive in a lower gear and try to hit at least 2000rpm on a single journey at least once a week.

I don't know if this is characteristic of other DPF equiped engines, if so then so be it but if peculiar to Honda then you would have to ask why.

Hope this helps.

Regards,
Chris
The DPF injects a small amount of diesel into the filter to 'kick start' the regeneration process and burn off all the accumulated crap. This is why your MPG drops. My Dad had massive problems with his on his Vauxhall Zafira, but I haven't heard of many issues with the Honda variant. Driving at ~2k rpm for ~15mins should clear the DPF out, so doing that at least once a week is a good idea if you do a lot of stop/start or low speed driving.
 

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JB it depends on what you mean by slow speed driving - I easily get up to 55-60mph albeit over reasonably short distances. Even then I rarely exceed about 1600rpm but here's the thing... to hit Honda's claimed mileage - 47.8mpg if memory serves - you would need to keep under 2000rpm for most of the time. Over a tankful the burning of extra fuel to keep the DPF in good order, in my view at least, would almost certainly mean that the claimed mpg couldn't possibly be reached!

I'd love to hear Honda's view on this, may give them a call but would any dealers care to comment?

Regards,
Chris
 

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Well as I said, when it's going through the regeneration cycle then it will squirt diesel into the filter to burn off the crud. You may notice a bit of smoke too.
 

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My understanding of how a DPF works (from previous experience with 2 DPF equipped cars) is that all cars with a DPF will regenerate (ie: as said above, help themselves to your diesel) every 200 - 500 miles, dependant on use. A DPF only becomes clogged if this regeneration cycle doesn't occur.

In order for regeneration to start, a number of conditions have to be met (ie: determined by sensors in the engine); the most critical of these is that the cycle won't start until the engine has reached full operating temperature and the revs are above tickover.

Therefore DPF diesel's doing lots of short runs are more liable to DPF problems - either because the engine never reaches operating temperature, or because although the cycle may have started, it doesn't complete due to the engine being turned off too soon. Generally speaking, for a DPF regeneration to successfully complete (especially in winter) the engine needs to run for at least 20 minutes from cold. If my understanding is correct; if the engine revs go down to idle for more than 30 secs or so, the DPF cycle will stop; even though it hasn't completed.

Please don't think I'm scaremongering here, but having run an Alfa diesel (that many owners had expensive DPF issues with), I read all I could about them to try and avoid problems myself. By always having the instantaneous fuel consumption displayed on the trip computer I could see when a DPF cycle started and found it was best to drop a couple of gears to build the revs up while the cycle completed (regeneration works by creating unbelievably high temperature within the DPF to burn all the crap off - talking several hundred centigrade). I never did have any problems with my DPF but always lived in fear of them; hence why I now drive a petrol even though I love diesels!
 

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Discussion Starter #12
My understanding of how a DPF works (from previous experience with 2 DPF equipped cars) is that all cars with a DPF will regenerate (ie: as said above, help themselves to your diesel) every 200 - 500 miles, dependant on use. A DPF only becomes clogged if this regeneration cycle doesn't occur.

In order for regeneration to start, a number of conditions have to be met (ie: determined by sensors in the engine); the most critical of these is that the cycle won't start until the engine has reached full operating temperature and the revs are above tickover.

Therefore DPF diesel's doing lots of short runs are more liable to DPF problems - either because the engine never reaches operating temperature, or because although the cycle may have started, it doesn't complete due to the engine being turned off too soon. Generally speaking, for a DPF regeneration to successfully complete (especially in winter) the engine needs to run for at least 20 minutes from cold. If my understanding is correct; if the engine revs go down to idle for more than 30 secs or so, the DPF cycle will stop; even though it hasn't completed.

Please don't think I'm scaremongering here, but having run an Alfa diesel (that many owners had expensive DPF issues with), I read all I could about them to try and avoid problems myself. By always having the instantaneous fuel consumption displayed on the trip computer I could see when a DPF cycle started and found it was best to drop a couple of gears to build the revs up while the cycle completed (regeneration works by creating unbelievably high temperature within the DPF to burn all the crap off - talking several hundred centigrade). I never did have any problems with my DPF but always lived in fear of them; hence why I now drive a petrol even though I love diesels!
Your understanding matches mine & I don't think you are scaremongering. People need to be aware that a DPF equipped car can be a problem depending upon driving style. I had a Nissan X-Trail 173 diesel & I had several DPF 'incidents' last winter when the weather was cold & with lots of snow around. Not what you need when you have to keep your speed down in poor conditions when a 4x4 is at its best. It made me late for work on several occasions as I drove up & down the dual carriageway outside work for up to 20 mins until the light went out. Diesels with loads of torque, 6-speed gearboxes and low rev cruising doesn't keep a DPF clear.........

Like you, I now drive a petrol car (in my case an Accord Tourer auto).
 

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I've not had any DPF issues to date (13K from purchase) except for it "helping itself to my diesel" (I like that phrase :)). And like 159John, when I notice the DPF drinking diesel I keep in max 4th gear even when I would normally go to 6th to keep revs and temp high. My morning/evening car commute is 18-20 mins each way.

It does seem perverse, to put it mildly, that what the engine manufacturers give with one hand (cleaner emissions) they take away with the other (higher fuel consumption). And from Pottsy's experience with his Merc it seems that Honda could do a lot more to get the balance right!

Regards,
Chris
 

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Not only that, but all the stuff that gets filtered gets burned out anyways so surely it's not actually doing much for the environment?
 

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Not only that, but all the stuff that gets filtered gets burned out anyways so surely it's not actually doing much for the environment?
I can't remember the exact temperature it's burned of at - but I know I was staggered to realise just how hot it gets inside the DPF during regen when I first read it. I guess this extreme heat burns off the nasty stuff without significant emissions.
 

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Your understanding matches mine & I don't think you are scaremongering. People need to be aware that a DPF equipped car can be a problem depending upon driving style. I had a Nissan X-Trail 173 diesel & I had several DPF 'incidents' last winter when the weather was cold & with lots of snow around. Not what you need when you have to keep your speed down in poor conditions when a 4x4 is at its best. It made me late for work on several occasions as I drove up & down the dual carriageway outside work for up to 20 mins until the light went out. Diesels with loads of torque, 6-speed gearboxes and low rev cruising doesn't keep a DPF clear.........

Like you, I now drive a petrol car (in my case an Accord Tourer auto).
Glad I'm not the only one who thinks the Eurocrats have ruined the modern-day diesel with all their green clap-trap! [smilie=ebil-thumbu:] If I'd kept the Alfa diesel, I was definitely going to have the DPF removed (and ECU reprogrammed) but unfortunately redundancy put paid to that particular avenue of pleasure! My only regret is in not realising that the Civic diesel (2007 era) didn't have a DPF (I thought they were mandatory); otherwise I would have bought that rather than the 1.8 [smilie=dunce.gif]
 

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I can't remember the exact temperature it's burned of at - but I know I was staggered to realise just how hot it gets inside the DPF during regen when I first read it. I guess this extreme heat burns off the nasty stuff without significant emissions.
Judging from the plume of black smoke that came out of my Dad's Zafira when the DPF was regenerating, it isn't good.

Seven months, two DPFs and an EGR valve later, he threw the keys back at the dealer and washed his hands of it.
 

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Judging from the plume of black smoke that came out of my Dad's Zafira when the DPF was regenerating, it isn't good.

Seven months, two DPFs and an EGR valve later, he threw the keys back at the dealer and washed his hands of it.
I presume that was the 1.9cdti engine? I had a non-DPF Vectra with that engine and couldn't believe the amount of smoke it belched. Cured it in the end by adding a dose of Millers to each tank. Not surprised the DPF and EGR caused problems. The two DPF diesels I've had never showed any visible smoke from the exhausts - at any time.
 

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Yeah, it was. He had nothing but problems with the car in the 7 months he had it. He was using it as a taxi, and not warned by the salesman, despite him knowing full well what he was going to be using it for. Needless to say, the DPF did not like this at all.
 

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A fair few people have had to go to their dealers to get a forced regen. There is two lights on the dash one telling driver its in regen and the second informing a trip to dealer is required.

There has been a TSB issued for this, alot of people buy DPF cars and just plod about town or stick to A roads. This sadly wont ever be a success for the idtec. Whether its a lack of buyer knowledge or a dealer issue I cant comment :facepalm:
 
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