[Wormtail]

I never had a problem with either of my last two cars and they were both diesels ... I did get told by a LR technician to maybe once a month take it up the motorway doing 70 for about 10-15 miles and that should keep everything happy in the engine .. but I didn't do it every month it was maybe every 6 -8 weeks and never had a problem ..

I was told the same by the guy that books in for servicing.. he even told me to drop a gear on the motorway to help it...

However with an analyser attached i found that at motorway speeds the DPF didnt get much hotter than driving at 40 mph, and dropping a gear if anything lowers the temp, i guess that the engine is working less hard at higher RPM... .......... a motorway run therefore will just increase the soot level in the DPF.

So my conclusion is a total waste of time driving just to try and clear it, when it needs to do a regen then yes higher speeds are much better and it happens much faster, thing is without additional equipment you don't know when it needs to do it!.

oh and final conclusion ,,, the LR service guys in general haven't a clue about DPF's

 

[Biker]

I was also questioning the logic of motorway trips, because with our stupid low speed limits on motorways, there is no way the exhaust temps will get anywhere near hot to burn off soot. As mentioned earlier, it will only delay the inevitable. Probably because there is a constant hot-ish air flow it still does something at highway speed. None of my freeway trips actually reduced the number on my app, only a regen will reduce reading from 7.99/8 down to 3. But it jumps back to 5 or 6 very quickly again
I'm getting better at gauging when regens need to happen and how to 'trick' its start.
Really short trip (I'd say under 2 miles/3km) and switch off engine & long interval (i.e. got to shop) mostly will not invoke it.
Near empty tank also questionable. I can state mine has done a regen with tank less than 1/4 full (25%), but pushing empty it has not. Once I filled up, I then make sure I do a longer trip as algorithm will kick in.

 

[Angel]

I was told the same by the guy that books in for servicing.. he even told me to drop a gear on the motorway to help it...

However with an analyser attached i found that at motorway speeds the DPF didnt get much hotter than driving at 40 mph, and dropping a gear if anything lowers the temp, i guess that the engine is working less hard at higher RPM... .......... a motorway run therefore will just increase the soot level in the DPF.

So my conclusion is a total waste of time driving just to try and clear it, when it needs to do a regen then yes higher speeds are much better and it happens much faster, thing is without additional equipment you don't know when it needs to do it!.

oh and final conclusion ,,, the LR service guys in general haven't a clue about DPF's

my guy wasn't a service guy he was technician guy who had just fixed my car for something else at the time so kinda knew about engines and cars .. but as I say I never did do it according to instructions I kept forgetting .. 🤷‍♀️
My Friends got a Toyota and she had the message pop up on her dash and had to drive a certain amount of miles above 50 MPH as well according to her manual.

 

[DKZ5745]

My other car is a Petrol RCZ, but there are some diesel RCZ’s out there & I know from the forum whenever an owner has a DPF problem, the advice given is a motorway blast, preferably in a lower gear, and invariably the outcome is that it sorts the problem.

 

[Torque]

On my previous car, a Mitsubishi, you could feel the regen...
I often did the extra tour untill the regen was finished. After 150.000km nodpf problem.

Purchased the Evoque at 23.000km, early may last year, and it's now very close to 40.000km, we regulary do longer motorway trips.
Think it's good for overal internal engine cleaning to do longer journeys.
On the Evoque only the smell and ticking metal are indicators the car was is regen... before you stopped.

 

[Wormtail]

On my previous car, a Mitsubishi, you could feel the regen...
I often did the extra tour untill the regen was finished. After 150.000km nodpf problem.

Purchased the Evoque at 23.000km, early may last year, and it's now very close to 40.000km, we regulary do longer motorway trips.
Think it's good for overal internal engine cleaning to do longer journeys.
On the Evoque only the smell and ticking metal are indicators the car was is regen... before you stopped.

I agree Diesel engines are better suited to hard work and long journeys.. the typical school type run is not ideal.... but that's what 90% of cars are used for .

well in a few years we will all probably be discussing recharge issues

 

[Doink]

And the funny thing is all the evoque TV ads show it doing city driving and tackling oversized speed humps, you then buy one only to be told 'ah but they aren't meant for stop start city driving' or 'your driving style has clogged the DPF, that's not covered'

 

[Noggin]

Just a quick question, using an obd reader with ability to force a DPF regen, would it damage it even if not needed, if I forced a regen
Thanks

 

[Wormtail]

Just a quick question, using an obd reader with ability to force a DPF regen, would it damage it even if not needed, if I forced a regen
Thanks

a forced regen should be fine, it will automatically stop when the dpf level gets to zero.

Personally i think that the cars should have a DPF gauge and the ability to force one whenever you want, so for example if its 85% full and you are on a motorway for a short journey you can clear it, rather than exiting the motorway with it maybe nearer 90-100%!

 

[Noggin]

Thank you, wormtail, can you guess what I'm doing this afternoon,

 

[DKZ5745]

Going to the pub? 🤔🤣

 

[Doink]

The thing with regens even if it's forced the dpf still won't get hot enough to regen, just because your forcing a regen it still won't or can't make the dpf run hotter, just my thoughts

 

[rawpilot]

The thing with regens even if it's forced the dpf still won't get hot enough to regen, just because your forcing a regen it still won't or can't make the dpf run hotter, just my thoughts

That's the point of a forced regen though i.e. it pumps fuel into the exhaust gases which causes the DPF to get up to around 600 deg C (red hot) and burns off the particulates. I've done it on my other car and it is a bit hairy as you can feel the heat and hear the metals under heat stress. I wonder whether something is going to catch fire (either my car or the road).

 

[Doink]

So how does it heat the dpf when it decides itself to regen i.e not forced - it pumps more diesel in but its been well documented and by JLR engineers themselves that the dpf can never get hot enough to regen and I assume forced or passive because it is too far downsteam in the exhaust system and in the airflow due to the lack of space between the back of the engine and bulkhead ideally bolted on the end of the turbo to get the full effect of the heat. I could be wrong as i'm only repeating what I've read on various JLR bulletins

Just to confirm, it pumps more fuel(diesel) into the engine not the exhaust hence why constant attempts at failed regens(dpf not reaching regen temp)cause excessive oil dilution, in an ideal world it would do one regen every couple of months, heat the dpf to the correct temp on the first attempt and its done and with little or no blow by of diesel causing oil dilution, the reality is though its trying to regen and failing every week thus causing oil dilution, timescales are just to illustrate my point and not a true figure

Thats how I understand what causes failed regens and thus oil dilution

 

[rawpilot]

So how does it heat the dpf when it decides itself to regen i.e not forced - it pumps more diesel in but its been well documented and by JLR engineers themselves that the dpf can never get hot enough to regen and I assume forced or passive because it is too far downsteam in the exhaust system and in the airflow due to the lack of space between the back of the engine and bulkhead ideally bolted on the end of the turbo to get the full effect of the heat. I could be wrong as i'm only repeating what I've read on various JLR bulletins

Just to confirm, it pumps more fuel(diesel) into the engine not the exhaust hence why constant attempts at failed regens(dpf not reaching regen temp)cause excessive oil dilution, in an ideal world it would do one regen every couple of months, heat the dpf to the correct temp on the first attempt and its done and with little or no blow by of diesel causing oil dilution, the reality is though its trying to regen and failing every week thus causing oil dilution, timescales are just to illustrate my point and not a true figure

Thats how I understand what causes failed regens and thus oil dilution

Yes, that's pretty much how I understand it.
It is continuous failed regens that cause oil dilution. With the forced regen, it completes the regen process with the car at rest by increasing the idle RPM and overfuelling until it detects the DPF differential pressure is OK.

 

[EvoMike]

Just to confirm, it pumps more fuel(diesel) into the engine not the exhaust

NO


Extra fuel is injected (Sprayed) into the Exhaust valve chamber (the Exhaust side of the engine) it is then taken with the exhaust gasses to the DPF and heats it up.
With failed re-burns excess fuel when the engine is turn off trickles down past any open exhaust valves into the piston cylinder.
It could stay in the cylinder until the engine is started, some could get burned .
Once the engine is running the pistons have whats called 'oil scraper rings' (one of several rings on the pistons) it's the job of the oil scraper rings to scrap back down engine lubricating oil back in to the oil sump (it is designed to leave a very very thin film to lubricate the moving piston) .
Problem you now also have excess fuel in the cylinder, so where does that go, yes it gets scraped back into the Oil sump thus diluting the oil.

 

[Angel]

I'm learning a lot in this thread but I wish you could all agree

I still say a quick trip on a motorway once a month cleared mine I don't know how but I didn't have anything pop up in my dash ,,, and car worked perfectly for 2 years and the other one for 3 years and I did a lot of town work .

 

[Col_C]

There's passive regen - which the Evoque struggles with (understatement), then there's active regen - which the Evoque does (I believe via injection on the exhaust stroke - there are different methods to achieve the same result) and is controlled by on-board software. And then there's forced regen which a JLR dealer or preferably an independent specialist can perform if you get an error message.
Google is your friend if you really want to research the subject.
But I stopped worrying about it a while ago, our Evoque does a couple of sub 2 mile journeys each week, the rest are typically 20 miles at moderate speed but rarely stuck in traffic. We only do about 5 or 6000mls a year and the oil service warning came on just before the 2 year service was due.
Just drive and enjoy!

 

[Wormtail]

The thing with regens even if it's forced the dpf still won't get hot enough to regen, just because your forcing a regen it still won't or can't make the dpf run hotter, just my thoughts

A forced regen injects diesel into the exhaust stroke and burns it in the exhaust creating 650 degrees in the DPF and burns off the soot !.... read back in this thread and you will understand how it works, it was discussed in detail

 

[Wormtail]

I'm learning a lot in this thread but I wish you could all agree

I still say a quick trip on a motorway once a month cleared mine I don't know how but I didn't have anything pop up in my dash ,,, and car worked perfectly for 2 years and the other one for 3 years and I did a lot of town work .

a motorway trip adds soot to the DPF unless you are towing or driving at around 100 MPH+.. I had the same mis conception but have monitored it in both my Merc and the Evoque and they both do the same.. its been detailed earlier in this thread!