Frustrating DPF regen times - need to vent!

I apologize since this has been probably said many times, but I continually find it frustrating that almost always, the days I drive over an hour into work (or home) it decides to wait until the last 5 miles of my trip to kick off a regen cycle. You're talking a good 10-15 minutes before it's done so I'm either riding around another 15 minutes or cycling the ignition and waiting for the numbers to drop. I love everything else about my car, but they really fell short here with whoever programmed this function.

My solution would be to show a light on the dash when a regen is needed, after which you can push a button when you know you're going to be driving sufficiently long for the cycle to finish. It could be user switchable mode for those who want control over this.

My thoughts would be to ignore whether a regen occurs and shut the car off when you want to. Why waste diesel waiting for a regen to finish.

If it is detrimental to the car, I would sell it and stop worrying about it.

I loved my VW, with all its quirks, but to own a vehicle...sorry that not the right wording...for a vehicle to own you and your time then its well past loving a VW and I would be long gone from ever owning a VW again. oh wait, I am....yet I still lurk on this site...

PAJettaTDI said:

My solution would be to show a light on the dash when a regen is needed, after which you can push a button when you know you're going to be driving sufficiently long for the cycle to finish. It could be user switchable mode for those who want control over this.

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Unfortunately VW decided that Americans were not smart enough to figure out what that light meant. Or perhaps they believed that Americans just don't want to know how our cars work (this is probably true for most Americans). Anyway, the only reliable way I know of to predict regens is to monitor calculated soot load from the ECU. I use a Polar FIS+ which displays this info in my MFD. Whenever soot load reaches 16.8g, a regen starts.

cleaver said:

My thoughts would be to ignore whether a regen occurs and shut the car off when you want to. Why waste diesel waiting for a regen to finish.

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...perhaps to protect the turbocharger. EGTs during a regen can exceed 800 degrees (C.) or 1500 degrees (F.). This is hot enough to melt aluminum and hot enough to break the down the best synthetic oils. I never shut of my engine when the turbo is that hot.

cleaver said:

If it is detrimental to the car, I would sell it and stop worrying about it.

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This may well happen soon, if/when there is a "buyback" offer from VW. However, this is unrelated to his regen question.

cleaver said:

I loved my VW, with all its quirks, but to own a vehicle...sorry that not the right wording...for a vehicle to own you and your time then its well past loving a VW and I would be long gone from ever owning a VW again. oh wait, I am....yet I still lurk on this site...

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You are entitled to your own opinion, and you can lurk anywhere you want.

Have Fun!

Don

A push-to-regen button would be great. I will drive around in circles so I don't shut down a 1100 F turbo.

Auto Polar can display the soot load. It will help predict when a regen will occur.

http://forums.tdiclub.com/showthread.php?t=414187

I would like a light or a push to regen. But since neither will happen I do this. I always look at idle rpm when getting near my destination. I can tell if I'm in a regen by that. I'll keep car in higher gear to help out. If I get surprised at a regen and need to park, I shut it off and restart and let it idle for a couple minutes to cool down. Shut down stops the regen and it doesn't start regen again when you start the car up right away.


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I just find it amazing that, by design, you must leave your car running (better yet, driving around in circles), until your turbo is done its cleaning and cooling down.

Once you switch to another make of car, or ditch the diesel and stick with VW, you will wonder why you ever put up with such nonsense. UNLESS, you are a car enthusiast who thinks this is normal.

Jbdesigns said:

I would like a light or a push to regen. But since neither will happen I do this. I always look at idle rpm when getting near my destination. I can tell if I'm in a regen by that. I'll keep car in higher gear to help out. If I get surprised at a regen and need to park, I shut it off and restart and let it idle for a couple minutes to cool down. Shut down stops the regen and it doesn't start regen again when you start the car up right away.


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I've heard this before, but not sure how to tell when driving. Can you only tell when idling? How many RPMs does it increase during regen? I'm fine with driving a few more miles.

I check while driving simply by pushing in the clutch and taking a quick look. Don't know if that is possible with the DSG but is easy with a manual.
Idle is normally right at 800 rpm. During regen it is noticeable at 900 rpm. If you really are at a stop then you also hear the fans going bezerk.

I used to drive around the work parking lot or driving down the street and back. Dumb, I just stop the regen with a turn of the key and then restart and let idle a couple minutes.


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I have a 4% hill just before home, that triggers the pressure difference sensor and starts the regen often. I shut down and restart, let it idle until the fan speeds lower and call it good. I have noticed a very loud buzzing from the turbo when reving it up during the cool down lately

I occasionally have a regeneration going when I arrive home in the garage or am parking somewhere. I just shut the car off and walk away. As someone commented, I am not going to have some function of the car dictate that I must sit (or drive) around until it's done running, and nothing in the manual says I should. If this is going to cause a problem, we'll just trade the car.

Nothing in the manual about keeping the car on during a regen or allowing the turbo to cool.
I just follow basic knowledge that you shouldn't run your car like a maniac right up to your driveway but just driving normally for the last 1/4 mile should be fine.

Hell, after taking a high performance driving course where we flogged CTS-Vs for up to 1/2 hour of time on the track for several hours a day, one moderate cool down lap of around 1 mile was deemed sufficient on a red hot car in Arizona heat.

Just understand that even on an "enthusiast" site, only a fraction of the people let the car run or even know what is going on. I don't even recall a section on regen in the manual but I could have forgotten, I am sure someone will point to the section if I am remembering wrong. I bet most buyers have no clue and probably don't even wait until the glow plug light shuts off before starting and they are fine as well.

I also found that if I had to interrupt a regen cycle, the under hood temperature went through the roof after the radiator fans stopped. If I arrived home when a regen was in progress, I always raised the hood, and had a fan I put in front of the car to blow air under the car. This helped the heat around the turbocharger, DPF and SCR area to dissipate between the engine and firewall. With no fan and the hood closed I was surprised parts didn't start to melt. Just something I did with my now sold '15 Jetta. I don't know if it helped anything or anybody but me, but from the hot smell coming from under the hood it seemed like the right thing to do.

Would this be the perfect application for a factory installed "Turbo Minder"?

Thinking back years ago, it was a device that idled the car for about 5 minutes after you shut it down, locked the doors, and walked away. It would shut it down automatically.....preventing coked up turbo's.

JSWTDI09 said:

Unfortunately VW decided that Americans were not smart enough to figure out what that light meant. Or perhaps they believed that Americans just don't want to know how our cars work (this is probably true for most Americans). Anyway, the only reliable way I know of to predict regens is to monitor calculated soot load from the ECU. I use a Polar FIS+ which displays this info in my MFD. Whenever soot load reaches 16.8g, a regen starts.



...perhaps to protect the turbocharger. EGTs during a regen can exceed 800 degrees (C.) or 1500 degrees (F.). This is hot enough to melt aluminum and hot enough to break the down the best synthetic oils. I never shut of my engine when the turbo is that hot.



This may well happen soon, if/when there is a "buyback" offer from VW. However, this is unrelated to his regen question.



You are entitled to your own opinion, and you can lurk anywhere you want.

Have Fun!

Don

Click to expand...

When I was monitoring regens on my CR170 I noticed no higher than about 650 degrees EGT and that was when moving on hills.
When idling egts were not that high. You will not have 800 degree EGT when idling

PAJettaTDI said:

I apologize since this has been probably said many times, but I continually find it frustrating that almost always, the days I drive over an hour into work (or home) it decides to wait until the last 5 miles of my trip to kick off a regen cycle. You're talking a good 10-15 minutes before it's done so I'm either riding around another 15 minutes or cycling the ignition and waiting for the numbers to drop.

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For me cycling the ignition is a much better option. It only takes 2 minutes for the EGT1 temp to get down to < 400F. Way better than 10-15 minutes.

xjay1337 said:

When I was monitoring regens on my CR170 I noticed no higher than about 650 degrees EGT and that was when moving on hills.
When idling egts were not that high. You will not have 800 degree EGT when idling

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You are correct about idling EGTs. At idle my EGTs during regens are well under 1000 degrees (F.). However, I have also discovered that too much idling during a regen just results in an incomplete regen. In other words, it quits the regen before it burns off all of the soot. This is not a serious problem, it just means that the next regen will occur a little sooner.
EGTs vary a lot while driving and perhaps even between cars. What I see is that during a regeneration EGTs are usually in the range of 1000-1200 degrees F. (537-650 C.) when driving. However this can vary a lot while driving. Temps between 1200-1400 (650-760 C.) are not uncommon and I have seen brief spikes of over 1500 when accelerating (this is about when the ECU's EGT limiting kicks in, cutting power). This may be a little higher than "normal" because my car does have a stage 1 tune with all factory emissions equipment still intact.

Have Fun!

Don

I'm of the opinion that raising the idle speed (with your foot!) doesn't help the regen at all, as you're probably LOWERING the exhaust temp (engine isn't under load).
I agree with the above: Whenever I've had an "idle" regen, the next one is always earlier than I expect.

My regens seem to occur at different intervals. I've seen soot levels as low as 16 and as high as 19.3 when the regen starts. Mileage between regens also fluctuates from 245-375 miles. I monitor with a polar-FIS.

I do a lot of highway driving and I'm at 95k in my '13. I don't believe I've ever had an "idle regen" that I'm aware of.


Josh

VeeDubFamily said:

My regens seem to occur at different intervals. I've seen soot levels as low as 16 and as high as 19.3 when the regen starts. Mileage between regens also fluctuates from 245-375 miles. I monitor with a polar-FIS.

I do a lot of highway driving and I'm at 95k in my '13. I don't believe I've ever had an "idle regen" that I'm aware of.

Josh

Click to expand...

This doesn't surprise me. You have a different engine with different emissions hardware that I do. I would expect the regeneration timing to be a little different. Your info is useful for other Passat owners.

Have Fun!

Don

If I have time I just drive around for a few minutes and let it finish. If I don't have time, i just interrupt it. 50k miles without any trouble thus far on my '13.

Mine usually occurs on my way to work, and sometimes at the very end and it's still regen'ing when I pull into the parking lot. I just turn off the engine and restart to interrupt the regen cycle, and let it run a minute or two to keep the oil circulating thru the turbo and cool down. It doesn't take very long. If I'm running late, I'll quick grab my stuff, lock and remote start it, then go get set up in my office, then come out a couple min later to turn it off. Yes, it a weird quirk I put up with, but I'd rather do that then have a fried turbo down the road when I least expect it......

jhinsc: No need to "...come out a couple min later to turn it off..." It automatically times out and will shut off on its own.

You've reminded me of this feature, though, which I've never used. Get out, remote start, walk away!!!

About the remote start: once I used it and noticed that the regeneration re-started after some minutes. The car self shuts off after a run time, and I'm not sure if it waits for the regeneration to end, so you might be back to square one. Have not used it since.

^^^I think you're right. The remote start shuts off after "x" minutes, totally unrelated to the regen (although that would be a very cool feature, possibly even programmable.)

I've never used the remote start function to assist in regen shutdown, but I'll guess the automatic shutdown occurs after ample time for the EGTs to have come down quite a bit. Simple to test it...doubtless someone here knows exactly how many minutes will time-out the remote start.

I have my doubts a regen would start if the car was just idling after a restart. Possible, but I'd be more inclined to believe it looks for actual driving activity. Unless it's reached a threshold that a regen becomes more critical to complete.

atc98002: I think the objective here is to interrupt the regen, you stop the car, get out, restart it remotely. The regen does NOT start again, but rather, the engine will continue to cool down at idle, and shut down automatically. No need to sit in the car, waiting for the interrupted regen to cool down.

tdiatlast: I agree that was the discussion, but c-wagen mentioned the regen restarting while using the remote start. So the question is, will the regen restart if the car is restarted and just sits there idling. I would hope the ECM recognizes the car isn't being driven and holds off resuming the regen until it moves, but if it will restart perhaps there's a timer that could be adjusted with VDCS to shut the engine back off before regen resumes.

I believe that a regen will not occur until the engine is at normal operating temperature. Sometimes when I arrive somewhere (usually work) I know a regen is about to happen based on the monitored soot levels. When my workday is over and I head home the regen will not start until the engine gets up to normal temperature.

Now if the car has been driven and a regen has already started shutting it down then using remote start may not "cool down" the turbo since the engine is already at normal operating temperature so perhaps the regen will just pick up where it left off?

I've never shut down during a regen. Only once so far have I arrived somewhere with a regen already in progress. On that occasion the regen was almost done so I let it idle and two minutes later it was done as I had time to wait.

I can predict when a regen will occur when I commute to work due to the regular driving pattern. On a road trip it is harder to predict when a regen will happen but it also will go much further between regens. Running to/from work I get a regen about every 150 miles while on road trips can be much as 425 miles between regens. Regen intervals depend on one's length of commute and driving conditions so what is true for me may not apply to another car/driver.

someone said a really long time ago that 35mph was required

jrm: I've never heard that one. I believe it will happily regen at idle, given enough time.