Anybody have a diesel with a particle filter?

[dkm777]

Hi guys,

First post in The Garage. I know it's a bit of a stretch to ask about diesels on an American dominated forum, but whatever. I have a diesel Volvo and I noticed something pretty annoying: if I drive only in the city for a few days it loses power, starts to shudder under hard acceleration and sounds like it's being choked. If I then take a trip down the highway for an hour or so it fixes itself. Does that mean my particle filter is clogged and driving hard for longer periods burns all the soot trapped in it? What else can be done about it besides a ridiculously expensive replacement? I once saw a fuel additive that supposedly helps burn the soot in particle filters, but I fear it's nothing but snake oil and might even damage my injectors or fuel pump. What do you think?

 

[LTC8K6]

Doesn't the Owner's Manual cover the operation/maintenance of the DPF?

 

[phucheneh]

We don't get diesel Volvos in North America, FWIW (literally none). My only experience with those filters is Ford trucks. They will do a cleaning cycle on the interstate (which can take forever), but I've never heard of the engine actually getting 'choked' by a restricted exhaust.

Not knowing your particular emissions standards at all, it's hard to throw a guess out there. I'm guessing you still have OBD2 or some kind of equivalent? Are there any lights on on the dash? Does the car use a urea additive?

What year, btw? I'm assuming pretty recent if it has a DPF.

 

[dkm777]

It's a 2005 and the manual is really vague about the cleaning process. It states that it should be performed automatically every few hundred kilometers, but there's no indication when it gets done. Also when the filter is shot a warning light must come on, but it never did and I fear the day it does come on. A trip to the stealership that means.

My friend, who is a massive gearhead said that I should replace the filter anyway, because the "cleaning" is a scam and doesn't really work. I would jut get it removed altogether, but then I'd fail emissions. The testing for diesels was made very strict a few years ago - if it comes with a DPF or cat form the factory it must be present and the contents of exhaust gas are measured at idle, medium speed and redline. There were plenty of horror stories about old engines being destroyed during redline testing.

And what is urea additive?

 

[pcgeek11]

It's a 2005 and the manual is really vague about the cleaning process. It states that it should be performed automatically every few hundred kilometers, but there's no indication when it gets done. Also when the filter is shot a warning light must come on, but it never did and I fear the day it does come on. A trip to the stealership that means.

My friend, who is a massive gearhead said that I should replace the filter anyway, because the "cleaning" is a scam and doesn't really work. I would jut get it removed altogether, but then I'd fail emissions. The testing for diesels was made very strict a few years ago - if it comes with a DPF or cat form the factory it must be present and the contents of exhaust gas are measured at idle, medium speed and redline. There were plenty of horror stories about old engines being destroyed during redline testing.

And what is urea additive?

Read about it here: http://www.dieselhub.com/howitworks/urea-injection.html

Urea is injected into the exhaust stream to reduce NOx emissions by using the ammonia to turn the NOx into N2 and Water.

 

[dkm777]

Thanks, that was good information. But I don't think I have that, not a word in the manual about DEF and I haven't found any mysterious tanks or reservoirs under the hood. I have a bad feeling that my filter is actually on its way out and the sensor that's supposed to tell me that is broken. It's an old and high mileage car (300+k km/190k miles). But I'll try the fuel additive anyway.

 

[LTC8K6]

http://www.volvoclub.org.uk/diesel_filter.shtml

 

[iamwiz82]

I have a BMW with a DPF. Every few hundred miles my gas mileage will drop about 20% for about 5 minutes. Yours could be clogged, it does happen over time.

 

[dkm777]

http://www.volvoclub.org.uk/diesel_filter.shtml

Damn, I should sell my car and buy a gasoline powered one :\.

 

[NetWareHead]

I have a VW Jetta TDI, also with a diesel particulate filter. When the filter is clogged or becoming full, the system will burn the accumulated particulates in the filter. You may want to get the car checked by a mechanic, your problems could be from a variety of causes.

 

[SyndromeOCZ]

I've got a 2008 Dodge Cummins which came stock with a DPF(odd, it no longer has it, I think it may have fallen off somewhere ).

Basically the way the DPF filter worked is the engine would run at a higher temperature and burn the soot out of the filter, it would peak over 2000 degrees F exhaust temp. If you ever had DPF issues and took it to the dealer they would suggest never idling it for long periods of time, and if your only doing city driving, then drive it like you stole it.

If you have a cracked DPF then it wont work correctly, and they actually cracked pretty easily.

 

[dkm777]

I've got a 2008 Dodge Cummins which came stock with a DPF(odd, it no longer has it, I think it may have fallen off somewhere ).

Basically the way the DPF filter worked is the engine would run at a higher temperature and burn the soot out of the filter, it would peak over 2000 degrees F exhaust temp. If you ever had DPF issues and took it to the dealer they would suggest never idling it for long periods of time, and if your only doing city driving, then drive it like you stole it.

If you have a cracked DPF then it wont work correctly, and they actually cracked pretty easily.

Yep, that's exactly what my daily commute looks like - stuck in traffic jams for almost ant hour each way. I also read that this is killer for Volvo D5s and some people report similar problems when they only drive in the city. So I now have a dilemma - a change to a small gasoline powered hatchback, or just go for regular longer drives on the highway just to help the engine clear its throat so to speak.

 

[_Rick_]

Get a Renault Twizy instead, and keep the D5 for longer trips

 

[dkm777]

Get a Renault Twizy instead, and keep the D5 for longer trips

This might be crazy enough to work. No, wait, I only have space for 1 car in my garage :'(.

 

[LTC8K6]

I think you just need to get it on the highway at high revs once in a while. It's high revs that get the DPF hot enough to get cleaned well, apparently. Perhaps stay 1 gear lower to get the revs higher on your highway run? Are your highway revs kinda low in high gear?

 

[olds]

We have them in our dump trucks. Idling plugs them up. Driving it like you stole it cleans them out.

 

[dkm777]

I think you just need to get it on the highway at high revs once in a while. It's high revs that get the DPF hot enough to get cleaned well, apparently. Perhaps stay 1 gear lower to get the revs higher on your highway run? Are your highway revs kinda low in high gear?

Mine's an automatic and crusing at the highway speed limit gives ~2500RPM. There's also a semi automatic mode and if I force shift to a lower gear to get 3000RPM, the fuel consumption goes through the roof! Kinda defeats the purpose of a diesel - to save a lot on fuel. Oh well, a small gasoline hatchback it is. I rarely take trips on routes that include the highway, so my cruising RPM in that case is just below 2000. Ant there's another thing to watch out for in older Volvo D5s - the dreaded variable vane turbo. When my father used to drive this car he did it very carefully to save fuel. A few years later the variable vanes seized because he didn't exercise them at all. That meant a replacement turbo. Ouch.

 

[PlasmaBomb]

Stolen from a VAG forum -

There are 2 types of regeneration, passive and active

During long motorway journeys, passive regeneration will occur. This needs no intervention from the engine control unit. Due to the raised exhaust temperatures on a long journey (temperatures between 350 and 500°C), the procedure occurs slowly and continuously across the catalytic-coated (with platinum) DPF. The catalytic-coated DPF is situated close to the Engine, therefore the exhaust gas temperature is high enough (500°C) to ignite the soot particles.
Due to this soot is burned-off and is converted into a smaller amount of ash.

Active ‘regeneration’ is when the ECU intervenes when the soot loading in the DPF is calculated to be 45%. The procedure lasts for about 5 – 10 minutes. Specific measures are taken by the ECU to raise the engine exhaust temperature to above 600°C, these include switching off the exhaust gas recirculation and increasing the fuel injection period to include a small injection after the main injection. The soot particles are oxidised at this temperature.

The ECU will trigger a regeneration process, if for some reason this is aborted, ie. customer slows down, stops etc, the process will be resumed when regeneration conditions are once again met, above 60km/h (38mph). This will continue for 15 minutes.
If after 2 attempts of 15 minutes, a successful regeneration has not been possible, the loading will increase. At 50% soot loading, the ECU will continue to maintain maximum exhaust temperatures of 600°C to 650°C to cause a regeneration process. The system will try to run a regeneration process for 15 minutes. If unsuccessful, the system will repeat this process for a further 15 minutes, if still unsuccessful, the DPF light on the driver display panel will then be lit.

More here -
http://www.seatcupra.net/forums/showthread.php?t=263734