DPF LIGHT

[mratk]

Hi all I’m just wanting to kno if anyone else uses .redex dpf. when there dpf light comes on? 
I have used if I have no long journeys coming up to clear the light.
just seeing if anyone has had problems using over the years to see if I should carry on using it 

cheers 

[Dulac]

I have never had cause to use it - just exclusively Shell diesel. The light doesn't come on (apart from all of them when the ignition is on to start the engine). I always understood the light to be a warning that the DPF is going wrong big time.

[mratk]

Ohh I see dulac i understand that the warning light comes on or flashes when it needs to clean itself out, mine hasn’t come on since I got it a couple months ago so just needed running back in when it’s been sitting and doing short trips. But I used the bottle of redex DPF and the light went in a minutes! Just in case it comes back on just want to see if it’s worth it.

[victor]

I've never used Redex DPF cleaner, made by Holts, another trusted (sort of) name from way back. Come to that I've never used any of the other DPF cleaner additives either but I understand they commonly work by adding cerium oxide to the fuel which lowers the temperature required for the soot in the DPF to burn off during a regen. I looked up the data sheet for Redex and they just say it's a mixture, containing a nanometal oxide catalyst as the active ingredient. Don't know whether it would work with the Adblue system but since we don't have that on the Antara it should be OK to use, you pays your money and takes your chance.

[mratk]

Well hopefully I don’t have the light come up again anyways as I do many miles for work! But if anyone is having problems with there dpf light then try ,REDEX DPF CLEANER May solove a problem before loads of money at the garage.

[chris]

mratk...my understanding is if you do enough long journeys then you will not see the indication. It will still do the "passive" regens as reqd. You only see the indicator when it is saying the dpf is full (probably due lots of short journeys) and you must then start the process manually i.e. "active" regen. Keep going (>30mph >2000rpm) until the light goes out.My car's the same as yours. Seen the light once in 15 months and after a 20 mins blast it went out.

some help her, but not much! www.vauxhall.co.uk/help-centre/owners/cleaning-my-diesel-particulate-filter.html

[mratk]

Hey chris.
I think It was just where it’s a mobility car when I sourced it going on couple years ago it was having problems but all clean and sorted now haven’t had a problem since.
Touch wood loool

[Richy]

My understanding is that the passive regeneration happens automatically when the exhaust temperature elevates above 350-400c. This naturally cleans the DPF filter just because on a good run the exhaust can reach these temperatures and the carbon is automatically burnt away from the DPF. This is really effective on things like diesel generators which run continuously under high load conditions and also on a system that uses passive regeneration the DPF filter is located close to the engine to ensure the exhaust gas doesn't cool to much before it reaches the DPF filter.

On an active system diesel fuel is injected through the engine cylinders whilst the piston is on the exhaust stroke and makes it way to the DPF filter, well certainly on fords and Jaguars that is how it works. By some method this fuel is ignited and elevates the DPF temperature to around 500-600c whilst the engine is running and burns off the waste carbon. This process is activated by the engine ECU automatically and is difficult to detect. A couple of tell tail signs are that if you interrupt this process by stopping the engine you will hear the engine cooling fan come on to remove a build up of heat within the engine bay, a second tell tail is an increase in diesel consumption which if your on a long run can be seen through poor economy on the trip computer. This will not normally illuminate the DPF light on the dash board.

If through lots of short journeys this active process is continually interrupted the DPF filter is unable to regenerate, and can block up further which will generate a greater differential pressure across the DPF filter. This is monitored by the ECU and when a certain level is reached this will trigger the warning light on the dashboard. The purpose of the light is to advise that the DPF is becoming critically blocked and request you instigate a long drive of probably 20-30 minutes at around 2000rpm to give the car chance to clear the blockage. Details are in the owners manual.

I'm not aware of any manual method of implementing active regeneration on an Antara, other than possibly at a Vauxhall dealership with the car plugged into their system. Again active regeneration is implemented by the engine ECU automatically.

The moral of the story guys is "no light no worry". My neighbour is a postman and has lots of problems with their vans. The lights noramally come on 2-3 times a week on their vans and often they have to leave the engines running to allow the active process to clear the filter. Hope my understanding helps.

[victor]

Good write up Richy, pretty much sumarises what goes on. A diesel exhaust is typically oxygen-rich (unlike a petrol engine) to react with the extra fuel injected in as part of the DPF regen. The catalytic converter is where the EGT is raised to about 600 before being passed through to the DPF to begin incinerating the soot. That's why the short-coupled DPF is standard on most diesels now. After each regen there is a little more ash left in the DPF and the ECU takes account of this in calculating when the next regen is due. You could go on for ever trying to explain every little nuance of the system but I think you've pretty well got it.

[Richy]

Thanks Victor, I have learnt something new regarding the action of the catalytic converter in the process. I have been putting together the pieces of how the system works for a long time, but I must confess expert technical knowledge like your is hard to come by so much appreciated.

[Dulac]

A good description, Richy and this should be useful to those who misunderstand the dpf process and warning light on the Antara diesel engine. Several years ago there were quite a few reports from owners who were suffering the effects of dpf/regen neglect, either self-inflicted or inherited from previous owners. The conclusions I reached a long while ago after 35 years of (mostly Peugeot) diesel car ownership were:

1. always use good quality fuel.
2. avoid short hops like the plague.
3. give the car an Italian tune-up on the motorway as often as you wish.
4. if a regen starts near the end of a journey keep going until it finishes (and always let the turbo idle for a short period before switching off).

The engine and its attachments are kept clean and moisture-free as a consequence.

[chris]

Hey Richy, (if you see this!) just to give you a heads up to a reply I tried to send you on the other site re thread Hands Free & BT. Couldn't get it to upload the message nor pics so sent pm to you. Hope that makes sense? If you like I could try again on this site if you start a new thread. Rgds Chris