Dpf regen concern

cav93

I've had a 2016 Passat 1.6tdi this last year, always got good long trips at least once a week. Would go into Regen maybe once a month or 6 weeks. But now with the restrictions I can only drive it to my place of work and the shop. Max journey 7 miles, so it wouldn't even be warm til it's stopped again and it has been in Regen mode all the last week. Would it be ok to continue like this for the foreseeable without doing any damage? My only other consideration is to buy a cheap run about for a while if I can find one with tax and nct and let it take the short trips, or does this seem like going overboard? I just don't want to harm the car with short trips until I am able to drive it further..

teediddlyeye

You'll be fine for a while.

When the warning light comes on for you to do a regen drive you still have loads of capacity in the dpf before you get an EML and needing a service regen.

zg3409

If you are saying it is "always doing a regen' does the fan stay on every time you park the car? If so I would do a spirited drive in a low gear and 40+mph and if possible look at mpg readout, or odb real exhaust temperature and make sure regen completes fully. Danger is if it starts a regen every trip, then oil will need replacing sooner, and eventually dpf will be full which can cause back pressure damaging turbo or engine. Do this once and then keep an ear out for the fan running when stopped. Typically 100km to 500km depending on age of dpf and driving style before it will need to be done again.

TheBoyConor

once a week on the way home just drive it in 2nd gear and rev it up to the absolute bollox and that will help clear any crap out of the exhaust system.

colm_mcm

TheBoyConor wrote: »

once a week on the way home just drive it in 2nd gear and rev it up to the absolute bollox and that will help clear any crap out of the exhaust system.

That’s not how a DPF works. Not sure if you’re trolling but you consistently give out blatantly incorrect advice to people who might actually take you seriously.

TheBoyConor

It's not a replacement for a regen but the high flow will definitely remove a lot of the loose soot and carbon from the exhaust system, particularly around the manifold and the egr.

If you've ever tried it on a diesel car that's been driven on short slow trips always you'd see that after 10 or 15 seconds you start getting bursts of black soot and crap flying out the exhaust. All that's clogging up the exhaust system and causes egr problems.

I used to do it on our Volvo S40

Toyotafanboi

TheBoyConor wrote: »

It's not a replacement for a regen but the high flow will definitely remove a lot of the loose soot and carbon from the exhaust system, particularly around the manifold and the egr.

If you've ever tried it on a diesel car that's been driven on short slow trips always you'd see that after 10 or 15 seconds you start getting bursts of black soot and crap flying out the exhaust. All that's clogging up the exhaust system and causes egr problems.

I used to do it on our Volvo S40

Might be decent advice if we are talking about a 20 year old Ttansit. It'll make SFA difference to OP's Passat, if anything it'll do more harm than good.

I wouldnt be too concerned over it for a few weeks anyway in fairness. If are doing only small trips you are also using less fuel and creating proportionately less soot. It's not like you are doing your old commute without a regen.

You may have only noticed it regenerating every 4-6 weeks previously but you can be sure it was doing it more often than that. The dynamic regenerations in those will work to create regen conditions from cold start if necessary, it doesn't wait to see you cruising on the motorway.

Be grand for while OP.

mgbgt1978

zg3409 wrote: »

If so I would do a spirited drive in a low gear and 40+mph

TheBoyConor wrote: »

once a week on the way home just drive it in 2nd gear and rev it up to the absolute bollox and that will help clear any crap out of the exhaust system.

OP, ignore this totally misleading 'advice'. A modern (Euro 5 onwards) DPF regen is best achieved by maintaining a speed constantly above 80kmh, at normal operating temperature. It shouldn't take longer than 15 to 20 minutes to complete. Your best option is to get onto a decent dual carriageway (or main road) so that you can maintain this speed. Most modern Cars will regen faster in 4th or 5th gear at relatively low revs. The only reason they need to travel at 80kmh is simply to allow air to cool the DPF during the regen.
A cheap OBD (EML) dongle and the free VAG DPF app will give you real-time information regarding DPF regens. If you use an app like this you can see that the regen process speeds up on the over-run rather than with the throttle open.

Also most modern diesels will throw a DPF light after a certain number of failed regen attempts. This won't put you in Limp mode but it does give you plenty of warning to get the car on to an open road and away from the stop-start driving that created the soot in the 1st place

mgbgt1978

TheBoyConor wrote: »

It's not a replacement for a regen but the high flow will definitely remove a lot of the loose soot and carbon from the exhaust system, particularly around the manifold and the egr.

If you've ever tried it on a diesel car that's been driven on short slow trips always you'd see that after 10 or 15 seconds you start getting bursts of black soot and crap flying out the exhaust. All that's clogging up the exhaust system and causes egr problems.

I used to do it on our Volvo S40

A DPF traps all soot. That's what it's for :rolleyes:.
If soot is getting past a DPF in a 2016 Car then the DPF has broken up and the OP's car is definitely in Limp Mode.

testarossa40

http://motoringmatters.ie/dpf-regeneration-during-covid-19-lockdown/


- "When a DPF has built up too much soot and hasn’t been able to burn it off, a warning light will come on. If this happens during the lockdown, you should not use your car at all until you can get it looked at by a garage at the earliest opportunity.

"...If drivers ignore the warning light and carry on using their car with a full DPF, they risk blocking the DPF altogether, in which case the car will enter limp-home mode."

cav93

Thanks for all advice. I looked into every comment and
saw which made more sense. Well while I didnt spash out on a cheap runabout, I have had reason to do a long enough trip about once a week, (40km return) so it seems to have subsided a bit and it's now not in regen every time its started. So a bit relieved. Also due a service in 2000km hopefully by then garages back open.

Dravokivich

TheBoyConor wrote: »

It's not a replacement for a regen but the high flow will definitely remove a lot of the loose soot and carbon from the exhaust system, particularly around the manifold and the egr.

If you've ever tried it on a diesel car that's been driven on short slow trips always you'd see that after 10 or 15 seconds you start getting bursts of black soot and crap flying out the exhaust. All that's clogging up the exhaust system and causes egr problems.

I used to do it on our Volvo S40

Id be wondering why you were driving a diesel engine at high revs, when the benefit of the design of the diesel engine, is the ability to deliver consistent power at a lower rev range.

TheBoyConor

I didn't always drive it like that. My mother drive the car mostly, and it was mostly short spins less than 20km and at a very leisurely pace. So it used to build up a lot of soot.
On the occasional weekend I'd be home and I'd be driving it I'd take it on the main road and floor it to the redline for a few minutes and there would be spectacular black clags visible in the rear view mirror. After a few minutes it would fade away and it would drive much better then.