DPF Soot Loading FORScan

[TomsFocus]

Morning,

Which DPF soot load parameter is the useful one?  One is 'closed' and the other 'open'...not sure what the difference is?  Just want to make sure there isn't another issue causing my jerking problem before I have the PCM update done.  EGR & MAF are working fine (although it is them causing the pull away dip same as it was on the mk2).  Temp sensors all seem to be fine.  Glow plugs cycle as they should.  Rail pressure is reasonably smooth, no major spikes or dips. 

[TomsFocus]

Someone must know surely lol?  

[TomsFocus]

Can someone check their own and report back?

Pretty sure it done a regen today...  Steady 70mph on cruise control, only doing 40mpg instant, the nose suddenly dipped as if I'd tapped the brake then the instant consumption rose to about 55mpg.  End of a regen maybe?  Considering the effort they went to on the body shape, extra undertrays, active grill shutter, hidden wipers etc I expected more than 55mpg at speed on the flat on the mk3.  I'm actually losing average mpg by driving on the dual carriageway.  

[FatHead1979]

20 hours ago, TomsFocus said:

Can someone check their own and report back?

Pretty sure it done a regen today...  Steady 70mph on cruise control, only doing 40mpg instant, the nose suddenly dipped as if I'd tapped the brake then the instant consumption rose to about 55mpg.  End of a regen maybe?  Considering the effort they went to on the body shape, extra undertrays, active grill shutter, hidden wipers etc I expected more than 55mpg at speed on the flat on the mk3.  I'm actually losing average mpg by driving on the dual carriageway.  

Which engine have you got in the new car?

[TomsFocus]

16 minutes ago, 1979Damian said:

Which engine have you got in the new car?

1.6 TDCi, 8v 115ps version.

[DJ_Andy_M]

You shouldn't notice your car starting or stopping a regen at speed. It's noticeable when you're stationary though. I know with my 1.5tdci she purrs a bit, the revs at idle are up and you can feel it in the steering wheel.

[TomsFocus]

23 hours ago, DJ_Andy_M said:

You shouldn't notice your car starting or stopping a regen at speed. It's noticeable when you're stationary though. I know with my 1.5tdci she purrs a bit, the revs at idle are up and you can feel it in the steering wheel.

Hopefully the 1.5 has been mapped a bit better with the extra few years knowledge/experience...though one of my mates returned his 1.5 after 18 months after many PCM updates and new parts as it was never right lol.  The mk2.5 1.6 I had before was always a bit jerky during regens on the move, especially under light throttle, but never such a harsh 'jerk' as this.  I keep meaning to take the laptop out and check the soot loading figures again.

Can't say I've noticed a regen while stationary in the mk3, the mk2.5 used to be awful for starting them in town, fans going mental etc.  I've never had fans running on after switch off in the mk3...in fact I've never heard the fan at all...not even sure it works lol.  Going for AC regas attempt number 2 on Monday (new condenser fitted) on Monday so guess I'll find out if the fan works then.  The stop start works almost every time I stop as well which I assume it wouldn't if a regen was in progress.

[Frembrit]

Don't know which is the useful one so to speak, but I monitored both DPF_Load% and DPF_Soot_LD% when my car (Mondeo) wouldn't regen last year.

Before fix

After fix and regen, 4 weeks later.

 

[TomsFocus]

Well I wasn't expecting more than 100% lol?

I wonder what the max percentage is.

Did you have to replace the DPF or was it that low just after a regen?

[Frembrit]

Yeah, the percentage figures seem strange. The car did go in to limp mode though.

DPF was fine, it was a blocked vaporiser in the exhaust, which meant it couldn't inject diesel to increase the exhaust temp to do a regen. (600+ degrees celcius needed on my car)

[Jonro2009]

I've just taken delivery of a 2017 Focus ST Line, it’s the 1.5diesel with powershift. I’m new to diesel engines, how can I tell when the car needs to perform a regen? How do I know when it is carrying out a regen and can I force one? 

[TomsFocus]

There's no way to tell it needs one until it's too late and the engine light comes on with limp mode...  It's supposed to be totally passive and you're never meant to notice it happening.  In reality, there are a few signs that one is happening, gruff engine note and more engine vibration, less-smooth power delivery, extra smoke/steam from the exhaust and a reduction in current mpg on the dash as well as the coolant fan running.  Won't necessarily get all of those though.

You won't need to force one on a new car, as long as it's not all town driving it should be fine and you can just forget about it for now.  

[Ryan_Tango]

I get that jerk when the regen first kicks in but only on the motorway, I tend to drop into 4th and go around 65-70mph just to help it along, lasts about 15 minutes and goes back to normal. Only performed 1 static regen just to feed my curiosity, it's ideal if you only do town driving.  

[Jonro2009]

Thanks Tom and Ryan. I use the car to drive to and from work 4 days a week. It’s a 25-30mile round trip and the majority of the drive is on an ‘A’ road at 60mph, there is a roundabout in the middle of the road otherwise it’s at a constant speed. Is that enough to encourage the car to look after itself? If I was to do a ‘static regen’ how would I go about doing it? I’ve not discovered a way to hold the car in 4th and keep the revs high yet either ☹️ Diesel and auto boxes are both new to me.

[Ryan_Tango]

Can you not select a gear using the gear stick? I thought you could use it as a semi automatic? I think that'll be long enough you'll have the coated DPF which looks after it self very well. 

[DJ_Andy_M]

5 hours ago, Jonro2009 said:

Thanks Tom and Ryan. I use the car to drive to and from work 4 days a week. It’s a 25-30mile round trip and the majority of the drive is on an ‘A’ road at 60mph, there is a roundabout in the middle of the road otherwise it’s at a constant speed. Is that enough to encourage the car to look after itself? If I was to do a ‘static regen’ how would I go about doing it? I’ve not discovered a way to hold the car in 4th and keep the revs high yet either ☹️ Diesel and auto boxes are both new to me.

That should be more than enough for it to trigger its own regen at some point. I do 60 miles a day mostly A Roads, and sometimes it'll choose to do it just as I get to work. So if I catch it coming off the A303 I'll do high revs between the junction and work and 9 times out of 10 this tends to be enough for it to complete.

[TomsFocus]

A static regen would need to be triggered by a laptop and FORScan.  I've done a couple myself with the old additive type of DPF but I'm really not a fan of doing it, even with the fan on full and the bonnet open the under bonnet temps get ridiculously hot without 70mph airflow, I wouldn't be surprised if the heat caused problems later on.  If it needs doing then fair enough but I wouldn't just do it for the sake of it.  I took this video a few years ago now, might be a bit different on the cDPFs, not tried it one of them yet.

I reckon your driving should be ok...  It's similar to mine, most journeys around 10-15 miles each way on 60-70 roads but with short town drives between.  I've had the mk3 for 550 miles now so still early days for me but the mk2 was stuck trying to regen constantly from the day I bought it until changing the DPF so this is a better start at least lol!  

 

[Jonro2009]

I’m not sure you can’t hold it in a gear at high revs because after a short distance I’m sure it changes up for you even if you are using the paddles.

you mentioned it potentially starting a regen right near the end of your journey, what happens in that circumstance? Will the engine still shut off when,you tell it too.

thanks for taking the time to explain this this  me, I really should have read up on all of this before now 👍 

[TomsFocus]

Well if you can't hold it in gear you'll just need to drive faster in top gear for higher revs.   Tbh, it doesn't need holding in gear during passive regen (on the road), it's the way of keeping temps up in the older DPFs but the PCM does that by retarding the timing, closing off the intercooler, running the glow plugs and adjusting the amount of oxygen available in the DPF with the EGR valve.  It shouldn't take any extra input from the driver as long as the PCM mapping has been done correctly.

The engine will shut off when you press the button, even if it's part way through a regen.  If this happens, you'll usually get the coolant fan running on after you switch off which is a tell tale sign that you've stopped it part way.  It's not an issue as long as you do a decent drive within the next few days so it gets the chance to regen again.

[DJ_Andy_M]

On 22/02/2018 at 10:07 AM, TomsFocus said:

The engine will shut off when you press the button, even if it's part way through a regen.  If this happens, you'll usually get the coolant fan running on after you switch off which is a tell tale sign that you've stopped it part way.  It's not an issue as long as you do a decent drive within the next few days so it gets the chance to regen again.

Be aware that it will start again as soon as it reaches the right temperature, so trying to get a decent run in sooner or later is recommended as otherwise the load level will keep increasing and if left too long will cause it to not regen at all which means either a damn good clean or a new DPF.

[TomsFocus]

Finally checked this again today lol.  Still none the wiser about the difference between the 2 but the percentages have dropped considerably since I last checked...looks like the cDPF will work fine with my driving.