Is my tdci trying to do a dpf regen....

[Jason87]

The last few times I’ve switched my car off it’s left the fan running as if the engine is hot on a hot day but it’s a cool evening. Is this the car trying to do a regen? It’s annoying as I went on a motorway run on Saturday but now it wants to do a regen? Does it just work on mileage? If this is trying to do a regen, do I just go and take it down the motorway tomorrow? Will it still do the regen as don’t  want to waste my time if not lol

[TomsFocus]

There are too many variables but essentially yes, it should trigger a regen again next time you go out as long as the engines warm and you've got enough fuel etc. 

It works on soot loading rather than mileage.  It doesn't know you're about to drive on a motorway.  Mine also often starts a regen on a 2 mile town trip, the days after doing several miles at speed.  It's just sods law!

[Jason87]

Ah ok thanks. So it I take it down the motorway today it should start the regen again? Basically it will keep trying to do it until it’s done?

[TomsFocus]

Yeah that's right, it'll keep trying it until it completes one.  If it fails too many you'll eventually get a warning light/message on the dash.

Doesn't have to be motorway speeds but the important thing is maintaining a steady speed without junctions and roundabouts etc.  

[Jason87]

Thanks. I suppose there’s no way il know when it’s doing a regen or when it’s done will I? Shame it doesn’t say on dash that’s it’s done it  needs doing soon etc 

[TomsFocus]

I can always tell when they're occurring, engine note gets gruffer and it feels different, but most people say they can't tell so depends how observant you are I guess.  Also depends which engine as the 2.0 uses a different setup to the 1.6/1.5.  

Best test is the fan test, keep the AC off and you'll hear if the fan is still running when driving at 30 or below.  Once it's stopped, the regen should be complete.

[Jason87]

Thanks, lastly, how many miles of motorway speed do I need to go for it to complete? I’m right by m4 so this is easy. I also have about 80 miles of fuel range, this is enough for regen to still work? As you mentioned fuel amounts. I’ve got the 1.6

[TomsFocus]

Again, too many variables really.  If the engine will be up to temp by the time you reach the M4 I'd say 20 minutes at 60+ should complete it easily.  But if you're right on the M4 you may have to wait another 5-10 minutes for it warm up first.

On the early Mk3 1.6s the regen starting was really noticeable, like a sudden jerk as if you'd tapped the brake while cruising.  Not sure if the facelifts were mapped any better but it's worth keeping an eye out for that.

Hmm, 80 miles range might be too low.  I don't know the exact minimum that it will still start at on the Mk3 but it shouldn't start if the fuel light is on.

[Jason87]

Thanks, engine should be warm by time I get the m4 so I’ll just go for 20 mins. I’ve got a 2011 mk2 so latest one. I’ll fill fuel up just in case too. Makes me wonder when it was last regend as I’ve been on quite a few long drives over the last year

[TomsFocus]

18 minutes ago, Jason87 said:

Thanks, engine should be warm by time I get the m4 so I’ll just go for 20 mins. I’ve got a 2011 mk2 so latest one. I’ll fill fuel up just in case too. Makes me wonder when it was last regend as I’ve been on quite a few long drives over the last year

Oh sorry, I assumed it was a Mk3 as your profile year says 2016.  Mk2 fuel light comes on at 50 miles so it probably will regen with 80 miles range, but if you can stick a tenner or more in that would be best.  They regen around every 500 miles so it's probably been doing them without you noticing so far.

Edit - Also worth noting, the DPF might be full of ash given that it's now 10 years old.  That might explain why it's suddenly no longer able to complete a regen.  Hopefully it'll clear if you take it up the M4 later, but if the fans still running after that, you may have to consider a replacement or sonic clean.

[DaveT70]

1 hour ago, Jason87 said:

Thanks. I suppose there’s no way il know when it’s doing a regen or when it’s done will I? Shame it doesn’t say on dash that’s it’s done it  needs doing soon etc 

When in regen mode the idle speed is slightly faster, fans are on full wack and I've found the temperature goes up a slight bit.

Once the idle drops back to normal you know it's done

[Tizer]

The later Euro V, Mk 2.5's are very fickle about when they will do a Regeneration. When I had one my daily commute was 40 miles, mostly Motorway, but mine liked to do a Regen at the same roundabout nearly every Tuesday morning before I reached the Motorway.

I also think that there must be a minimal fuel level for a Regen to happen. Just an intelligent guess on my part, I don't have anything to back that up other than knowing that a lot of other things in modern cars need do not happen unless the fuel level is above a certain amount.

[Jason87]

I just took it for a 30 Mile drive up and down the motorway but didn’t hear the fan come on at all on the way. I hope it’s done it 

[Janzup]

You can montior the DPF load and force a static regenration using Forscan via OBD 2 cable if I am not mistaken. That would be the best way to monitor the actual load.

[Tizer]

27 minutes ago, Janzup said:

You can montior the DPF load and force a static regenration using Forscan via OBD 2 cable if I am not mistaken. That would be the best way to monitor the actual load.

That is correct, although with that model, if it is the Euro V one, there is no Soot Load but you can monitor the Differential Pressure and the DPF Temperature as well as doing a Static Regeneration.

[MarkRS9]

My mk2.5 Focus 1.6TDCi sometimes has the fan running when I stop, indicating it's trying to do a regeneration, I've never worried about it and just keep using the car as normal and have never had a warning message in the 9 years and 128,000 miles I've owned it. 

[Jason87]

Fan hasn’t come on since so hopefully it did a regen. I now have the intermittent “no gps” on my standard sAtnav which is annoying. Non stop common faults with this car 😞

[TomsFocus]

On 5/27/2021 at 7:31 PM, MarkRS9 said:

...never had a warning message in the 9 years and 128,000 miles I've owned it. 

There isn't one for the DPF on the Mk2 or 2.5.  It doesn't give any warning until it's too late, then it'll just give the EML or 'engine malfunction' message, maybe with limp mode as well.  Major design flaw and one of the reasons the 1.6TDCi was known for it's unreliability with non car people - no service interval timer and no DPF light, madness!

If you've never had an EML or warning message for anything in all that time though, that's definitely impressive!  

[MarkRS9]

9 hours ago, TomsFocus said:

There isn't one for the DPF on the Mk2 or 2.5.  It doesn't give any warning until it's too late, then it'll just give the EML or 'engine malfunction' message, maybe with limp mode as well.  Major design flaw and one of the reasons the 1.6TDCi was known for it's unreliability with non car people - no service interval timer and no DPF light, madness!

If you've never had an EML or warning message for anything in all that time though, that's definitely impressive!  

Only time I had the EML and warning message was when the egr packed up, replaced it, programmed and all good again.

service message comes up once a year.

[TomsFocus]

28 minutes ago, MarkRS9 said:

Only time I had the EML and warning message was when the egr packed up, replaced it, programmed and all good again.

Service message comes up once a year.

Ah, yours must be a late one if you get the luxury of a service reminder!

Now I'm wondering if anyone has owned one without ever seeing the EML.  In fairness, mine only chucked the engine malfunction message once for the glow plugs...which were prematurely worn by constant DPF regens, though mine did have the older additive type DPF.  (EGR and DPF were deleted after that so no errors possible!)

[MarkRS9]

23 hours ago, TomsFocus said:

Ah, yours must be a late one if you get the luxury of a service reminder!

Now I'm wondering if anyone has owned one without ever seeing the EML.  In fairness, mine only chucked the engine malfunction message once for the glow plugs...which were prematurely worn by constant DPF regens, though mine did have the older additive type DPF.  (EGR and DPF were deleted after that so no errors possible!)

Yes my car is one of the last mk2s (built May 2011) and was surprised the first time the service reminder come up, as my 2010 mk2 Focus RS doesn't have it.

The car has been one of the most reliable cars I have owned, probably helped by the fact I changed the oil every 6,000 miles.