Can someone explain regeneration to me?

[FR550(170)]

Hi all. First post here. I have a 2008 FR550 Tdi which about twice a week decides to run at 1000 rpm at tickover rather than 800odd rpm. Its noticably faster and when i drive it the accelerator feels more juddery and sensitive. Also notice that the exhaust makes a wee bit more of a rumble when it runs like this.

I use it to run to work (8 miles in and 8 miles back on mostly A roads). But at weekends its runa little quicker than rush hour traffic!

This as i say happens maybe twice a week and when takes a good wee while to go away. Sometimes it can sort itself before i get home/get to work sometimes not.

The car only has 10k on it and ite been into Seat and plugged in and they say nothing is wrong with it.

Is this the regeneration that causes this? Any help would be appreciated.

Cheers

 

[Nath.]

Sounds like regeneration, yes.

The exhaust pressure either side of the DPF is monitored and when a pre set pressure difference is sensed due to soot blocking the filter the system will gointo regen mode.

The soot builds up if the exhaust system does not get hot enough for long enough to burn the soot away.

Regen mode means extra fuel is injected during the exhaust stroke of the engine (exhaust valves open). this makes the exhaust temp rise to a point where the soot can be burned away.

That's it in laymans terms.

I take it the dealers gave you a leaflet on how to drive in a way that helps the DPF to do it's stuff.

 

[pacm0n]

Hi, I'm no expert but when its in 1st stage regeneration it ticks over at 1000rpm, the ecu adjusts things like fuel injection also.

Its basically to clear the DPF to avoid it getting blocked. You only do short journeys so it doesn’t get hot enough to clear itself, hence going into 1st stage regeneration.

Seat wont do anything until the DPF light and engine management light has come on. If you get the DPF light refer to your handbook and drive as stated and it should clear itself. If you get the DPF light and engine management light you go into limp mode and its a trip to the dealers I’m afraid.

If its going back to 800rpm after so long its done its job and cleared the DPF to an acceptable level. All I can say is as soon as or if you get the DPF light drive the car as stated in the handbook.

I’m sure someone else will be along soon to give you a more detailed response but that’s as much as I know I’m afraid.

It might also be worth doing a forum search for “DPF” and you will find quite a lot of other threads to help you along.

 

[Nath.]

Take it for a nice long drive out this bank holiday weekend and see if it does any good.

 

[pacm0n]

This page might also be worth a read along with all the info on SCN:

http://www.theaa.com/motoring_advice/fuels-and-environment/diesel-particulate-filters.html

 

[itsmefishy]

take it for a long blast! at legal speed limits of course!!

 

[londonfr550]

Im having the same problem in my fr550 diesel, ive had the light on once and done what the manual said to do, but sometimes i still get the same problem but no light. the dealer has a look at it and said they couldn't find any fault on there systems. what is the next stage

thanks

David

 

[pacm0n]

Im having the same problem in my fr550 diesel, ive had the light on once and done what the manual said to do, but sometimes i still get the same problem but no light. the dealer has a look at it and said they couldn't find any fault on there systems. what is the next stage

thanks

David

The dealers won't do anything until the DPF is fully blocked, (limp mode, DPF light, Engine Management light and coil light).

Then its either manual regeneration (usually at a extra cost) or worse case scenario new DPF!

If its idling at 1000 rpm but your not getting the light then going back down to around 800rpm the dpf has cleared itself to an acceptable level, you only need to worry when you get the light.

I know its annoying when they are idling at 1000 rpm but not a lot you can do about that.

Do you do short stop start journeys? This will block the DPF up quicker.

 

[londonfr550]

The dealers won't do anything until the DPF is fully blocked, (limp mode, DPF light, Engine Management light and coil light).

Then its either manual regeneration (usually at a extra cost) or worse case scenario new DPF!

If its idling at 1000 rpm but your not getting the light then going back down to around 800rpm the dpf has cleared itself to an acceptable level, you only need to worry when you get the light.

I know its annoying when they are idling at 1000 rpm but not a lot you can do about that.

Do you do short stop start journeys? This will block the DPF up quicker.

yep every day

 

[pacm0n]

Take it for a blast once a week or something to get the DPF hot, the heat burns off the excess soot clearing the DPF.

Constant short stop/start journeys are not good for the DPF so i'm guessing your going to get the idling at 1000 rpm quite frequently even with a good blast every now and then

 

[Nath.]

yep every day

You have trouble brewing then.

You may find it's cheaper in the long run to get the DPF removed, it's about £800 but that's only what it costs to have the stealers work on your DPF twice....................