How can I tell if my Citroen Picasso 3 is Regenerating please??

Mustbeananswer??

It seems to be a huge issue with Diesel Cars.

I have had the dpf cleaned and been on along run and its fine.

But I dont want to keep having it cleaned.I really only use it for local.

Im being told to take it on regular runs of 250 miles....are my colleagues winding me up ??

It has a whirring sound under the bonnet when I park after a long run ....is that the regenerator working ??

Mildly_Miffed

The issue here is your usage.

Either change that, and use the car at least semi-regularly for longer runs, or change it for one more suitable to your use.

The key to DPF regen is heat. The exhaust has to get properly hot, hot enough for the regeneration to work - for the extra fuel to be injected and the collected soot burned off. There's no magic speed or revs or mileage or anything else.

The whirring sound may just be the cooling fan. Regeneration doesn't, can't take place with the engine switched off.

Mustbeananswer??

Thank You Mildly Miffed....good information.

I am amazed in 2024 we need to go a certain amount of miles fast so that the system works when traffic is making us slow ?? 

daveyjp

DPFs been around for about 20 years, so its well established now that if you aren't doing the mileage don't buy a diesel.

DPF cleaning is only a temporary measure.  At some point you will need to replace it.

Mildly_Miffed

It's basic physics. The exhaust simply never gets hot enough for the DPF regeneration to work on a diet of exclusively short journeys, low speeds.

That kind of usage has never been good for cars, and is even less so for DPFs.

ontheroad1970

It would be useful if manufacturers would put a light on on the dash so that you can drive around little longer if you wish so as not to interrupt a regen leaving the fuel dumped in the oil

chrisw

250 miles is excessive. A 20 minute drive on the motorway, perhaps in a lower gear than usual, should be sufficient every couple of weeks or so. 

The regeneration does produce a lot of heat so the cooling fans running when you stop could well be an indication, although it could just be that it's hot. You'll often find the start/stop disabled as well. 

Nasqueron

Mustbeananswer?? said:

Thank You Mildly Miffed....good information.

I am amazed in 2024 we need to go a certain amount of miles fast so that the system works when traffic is making us slow ?? 

A lot of people bought diesels for the quoted MPG and low car tax without reading all the details - diesels are never suitable for short local usage only, you should buy a petrol (or now, a hybrid/PHEV/EV). My only daily driving in a diesel is to the supermarket/gym/local routes but due to the sport I do and distance from parents, I will have weekends where I drive for 1-4 hours each way on motorways which is ideal for diesel and ensures there is no DPF issue.

If you are going to continue driving only locally, I'd sell the car before the DPF goes and get a more suitable vehicle or as above, do some more regular long distance driving on weekends out, where the car can run for a while and regen

Goudy

Short trips as mentioned don't allow the exhaust/dpf to get hot enough to burn the soot to ash.

Soot is quite a large particle, ash is far smaller so the dpf can hold lots more ash than soot.

To burn the soot to ash it needs to heat above 450c or more.

Also short town trips on and off the accelerator tends to cause too much fluctuation in exhaust temp to complete most regen cycles. 
Exhaust temps cool when on the gas and scream mad hot when you take your foot off the gas pedal and it just pumps air on the over run.

So rich running is cooler than lean running, so much so a lean engine produces masses more heat 

The advice regarding taking it on regular motoring trips is right but you don't really want to hold it in a lower gear while clogging the accelerator, that is just throwing loads of fuel in the engine which in it's self produces more soot 

You'll get a much higher exhaust temp sooner the less fuel you inject into the engine. So get it up to speed and back off enough to inject just enough to maintain that speed and keep it there for a few miles. That will cause it to run as lean as it can and produce the heat the dpf needs.

sevenhills

ontheroad1970 said:

It would be useful if manufacturers would put a light on on the dash so that you can drive around little longer if you wish so as not to interrupt a regen leaving the fuel dumped in the oil

There is a light on the dash that will illuminate when the car is regenerating. I am not sure what it is on a Citroen Picasso 3.

In the 4 years that I have had my car, it has only done a regen a few times, that I am aware of and I do mostly short journies too. Mine is a 1.7 diesel Vauxhall. Older cars could of course have had their DPFs removed and we wouldn't know.

Regens will easily be done on 30+ minute long motorway journies.

35har1old

Mustbeananswer?? said:

It seems to be a huge issue with Diesel Cars.

I have had the dpf cleaned and been on along run and its fine.

But I dont want to keep having it cleaned.I really only use it for local.

Im being told to take it on regular runs of 250 miles....are my colleagues winding me up ??

It has a whirring sound under the bonnet when I park after a long run ....is that the regenerator working ??

When DPF light comes on is it constantly on or does it flash and has the car gone into limp mode?
Had a Volkswagen Golf that required to be modified due to the fraud on emissions after that the fan would run on after ignition switch off