How to tell Regen is going?

After just having my DPF replaced, luckily under warranty (74K miles) I am now paranoid that this will happen again, maybe even sooner than the first one...

My commute to work is about 30 miles one way, then I drive to lunch about 3 miles round trip, then back home after work another 30 miles, unless i have errands to run....Is this enough driving to successfully allow a regen of the DPF?

Do I need to drive longer trips to allow the engine to burn off the excessive soot??

Is there any way to monitor or tell if the regen has started??

I have the Maestro RR which interfaces with my Kenwood DNX694S

Maestro RR Jetta interface

I don't know how to tell if regen is occurring or needs to, any way to tell???

HWY Miles

Doing 30 miles to work Hwy at 23 at least your good.
your rpm will jump up so they say.

That commute seems alright. Like Rodmiser said you will notice your rpms, when stopped, about 100rpms higher and your fans are working (typically sometimes when you park your car and walk away and you hear the fans going for example).
I heard fuel is a factor, dunno for sure, but if it's true try to fill at a busy fuel station like where trucks fill up. Fuel is always "fresh".
I have a monitoring system (Bully Dog Watchdog) and have a section with exhaust temperatures and it gives a warning when regen is happening.

Most members use Scangauge II to monitor the car, check it out

Get a nice OBD scan tool and monitor with the Vag DPF app. I use an OBD LINK LX. ScanTool 427201 OBDLink LX Bluetooth: Professional OBD-II Scan Tool for Android & Windows. You can get the app in google play.

joe schmoe said:

After just having my DPF replaced, luckily under warranty (74K miles) I am now paranoid that this will happen again, maybe even sooner than the first one...
My commute to work is about 30 miles one way, then I drive to lunch about 3 miles round trip, then back home after work another 30 miles, unless i have errands to run....Is this enough driving to successfully allow a regen of the DPF?
Do I need to drive longer trips to allow the engine to burn off the excessive soot??
Is there any way to monitor or tell if the regen has started??
I have the Maestro RR which interfaces with my Kenwood DNX694S
Maestro RR Jetta interface
I don't know how to tell if regen is occurring or needs to, any way to tell???

Click to expand...

On mine at least, the rpm at idle will rise to between 900-1000rpm and you can hear the fans going. During my first regen, i had strange idle fluctuations causing the car to shake a little, but subsequent regens haven't had such symptoms. Id assume if you fill up using lower quality fuel, it probably wont burn as well and create more soot. I just fill up at a quik trip which is just off the highway on my way to work (no additional fuel treatments added to the tank). I dont notice mine doing very many regens but i make sure i drive my car pretty hard once a week.

These regen every 200-300 miles. You should be actively monitoring regens so you can prevent interupting them.

Like GreenLantern said, get a ScanGauge or some other tool and monitor DPF temperature. If it's over 1,000°F, a regen is happening.

tdiinsc said:

On mine at least, the rpm at idle will rise to between 900-1000rpm and you can hear the fans going.

Click to expand...

At idle, yes, but I can't tell when I'm driving down the highway.

I have a P3 gauge and the only indication that I've found by using it is that the cooling temperature goes up a few degrees. At idle it will rise up to 209 F or so. Going down the road, maybe 205.

Its definitely good to monitor regens for the shorter commute. My commute is too short for a diesel - only about 8 miles, so when it wants to regen I take a longer drive to let it do its thing. Does anyone know how much time or miles it take to regen? Is it fine to simply let it idle in the driveway or should I stick with driving it while it regens?

You should be able to get that P3 to read one of the exhaust gas temperatures, which will be more indicative of DPF regeneration.


there are three different regeneration activities, with varying duration and frequencies.
https://www.myturbodiesel.com/wiki/dpf-obd-charts/


I put this together a while ago.


the DPF gets regenerations, more often the NSC gets elevated exhaust temps and a bit of extra fuel to purge accumulated NOX. and once every four or five DPF regenerations, the NOX cat gets hot exhaust gasses with a different dance of fuel/air mixes, for about 20 minutes to get rid of accumulated Sulphur compounds.



the 2.0 liter SSP document is no longer at the linked site.







If you decide to wait in the driveway at idle, the regeneration will either finish, or stop, then start again next time you drive long enough to warm up.


either way is probably fine.


(it also probably is just fine to just drive the car, ignoring the emissions system)

KITEWAGON said:

At idle, yes, but I can't tell when I'm driving down the highway.

I have a P3 gauge and the only indication that I've found by using it is that the cooling temperature goes up a few degrees. At idle it will rise up to 209 F or so. Going down the road, maybe 205.

Its definitely good to monitor regens for the shorter commute. My commute is too short for a diesel - only about 8 miles, so when it wants to regen I take a longer drive to let it do its thing. Does anyone know how much time or miles it take to regen? Is it fine to simply let it idle in the driveway or should I stick with driving it while it regens?

Click to expand...

My trips are about as long as yours....but i have 3-4 miles of highway in between. If i'm able to i will drive a bit longer to let the regen finish, but if its in the middle and i arrive at work, i dont wait. Sometimes if you try too hard to follow directions, you end up driving yourself crazy

meerschm said:

You should be able to get that P3 to read one of the exhaust gas temperatures, which will be more indicative of DPF regeneration.

Click to expand...

It does read EGT. Though I don't know what sensor its reading. The problem for me is that EGT is all over the place depending on how much throttle you're giving it. I like the coolant temp because it seems to be steady in the high 190's but then goes into the 200's during regen.

KITEWAGON said:

It does read EGT. Though I don't know what sensor its reading. The problem for me is that EGT is all over the place depending on how much throttle you're giving it. I like the coolant temp because it seems to be steady in the high 190's but then goes into the 200's during regen.

Click to expand...

True, EGT readings do swing pretty wildly, but a regen is unmistakable. Under full throttle (not in regen), my EGT might hit 1100-1200, but immediately drops down once I let up on the pedal. Under regen, EGT stays consistently in the 1100-1300 range, even at light throttle cruise situations.

I monitor my coolant temp and EGT using a ScanGauge2, and I never notice the coolant temp bumping up during a regen. But because of my commute (225 miles daily round trip, all highway), I end up seeing a regen once a day, and they are almost always done at highway speeds.

soldierguy said:

True, EGT readings do swing pretty wildly, but a regen is unmistakable. Under full throttle (not in regen), my EGT might hit 1100-1200, but immediately drops down once I let up on the pedal. Under regen, EGT stays consistently in the 1100-1300 range, even at light throttle cruise situations.



I monitor my coolant temp and EGT using a ScanGauge2, and I never notice the coolant temp bumping up during a regen. But because of my commute (225 miles daily round trip, all highway), I end up seeing a regen once a day, and they are almost always done at highway speeds.

Click to expand...

Thanks that’s great information

My KENWOOD DNX694S has the Maestro RR which will read both coolant temperature and EGT temperatures.
I’ll just monitor these 2 and see.

Thanks again.


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