Interrupting Regen Every day.

[Turboneon1997]

My neighbor and I have almost identical Jetta TDI sedans, i work across town or about a 60mile round trip. He is retired and volunteers and has a daily commute of about 15 miles. I almost never interrupt a regen, he comes home every day and his car is in regen. He is not a car guy so I asked him how often his fans are running when he gets out of the car. He told me about every other time.

So the discussion began. He know the car isn't the best for FE but he had other plans in mind when he bought it but likes the car. I feel like I made him scared of his own car because he asked me replacement cost of the DPF, since we are both close to Emission warranty expiring(I am much closer, but stg 2 is coming for mine.

He asked me if he should trade the car, I personally believe that he would be better off in something small gas or fully electric if he is looking FE, and lower cost of repair.

Opinions?

 

[AlcoC420]

I'd suggest that he take his TDI for a highway drive at higher RPMs perhaps once a week for maybe 20 minutes? But, yes -- his lifestyle isn't well suited to modern diesel emissions systems.

VW will soon have a Jetta Hybrid that may suit his fancy:

http://www.edmunds.com/volkswagen/jetta-hybrid/2013/road-test.html

 

[Turboneon1997]

Thats what I suggested, take a nice long spirited drive on the highway. I also told him about the hybrid coming soon, but I think he is pretty anti-hybrid.

 

[Schubert]

Once he takes it for a good highway drive it shouln't come on again for at least a week I would think. I think if he can program a nice Saturday drive into his schedule both he and his car should be perfectly happy. Seems like less hassle and expense than trading in a car he likes...

If he does the long drive and it still comes on shortly after I would suspect cruddy fuel.

 

[VeeDubTDI]

He's gonna be looking at a new turbo before 100,000 miles if he keeps interrupting regens on a regular basis.

If it's regenning when pulling into the driveway, let it idle until it finishes. No need to go out of your way on the highway during rush hour or anything like that - it will complete just fine at idle.

 

[TNriverjet]

I agree, tell him to go enjoy the driving experience once a week or so... My goodness, he's driven it a while and not caught the bug on his own?

Also, I drive 3-4,000 miles a month, so I treat mine to regular full-cycle regens at road speed. However, this fall it seems like I'm interrupting regens more often too. Does the soot loading rate increase in cold weather? ...it does take longer to warm up... Just wondering if cold temp operation lends itself to higher soot output?

 

[WutGas?]

Interrupting a regen every other time he drives it? I would think there would have to be something wrong with the car for this to happen.

 

[RomanL]

its weird that regen goes on every day for him (15 miles is not that short of a commute to cause daily commute)
can you ask your neighbor how many miles on the car?
and when was the last oil change?
and was it doing regens daily before the last oil change?
if i understand correctly using incorrect oil could cause DPF to clog up and cause daily regens??

 

[VeeDubTDI]

The regen happens every day because he keeps interrupting it! The car wants to complete the regen so it keeps trying.

Regens will increase in winter months due to the reduced quality of winter fuel, cooler weather, and increased fuel consumption.

I know it's supposed to be seamless, undetectable, blah blah blah whatever, but the bottom line is that as an operator you should be aware of what's going on with your car. For the longevity of your vehicles, it would serve all of you well to let your regens complete when they are in progress.

As much as some people want them to be, TDIs are not transportation appliances that you just put "gas" in and ignore everything else. You can get away with that for a little while, but it will catch up with you in the end with increased maintenance costs and failed components.

 

[> Luke <]

He's gonna be looking at a new turbo before 100,000 miles if he keeps interrupting regens on a regular basis. If it's regenning when pulling into the driveway, let it idle until it finishes.........it will complete just fine at idle.

That's a revealing alert/input.

 

[Henrick]

Wow. My daily commute is usually 6-7 miles. And I plan on doing some longer trips on weekend. Hope that regen stuff won't hurt much.

 

[Dozenspeed]

I know it's supposed to be seamless, undetectable, blah blah blah whatever, but the bottom line is that as an operator you should be aware of what's going on with your car. For the longevity of your vehicles, it would serve all of you well to let your regens complete when they are in progress.

Since they didn't give me so much as an indicator light of the system functioning, I'm GLAD I can tell when it's doing it for habit management and vehicle consideration.

Funny how the Germans can be SO EXACTING in their engineering, yet so very oblique in telling anyone about it. Perhaps that's their sense of humor, and why everyone assumes they don't have one!

Justification for the previous statement: My heritage is significantly German. Und ja das ist funny!!!

As much as some people want them to be, TDIs are not transportation appliances that you just put "gas" in and ignore everything else.

I agree, that's what Japanese cars are for, and why I got my wife a Honda. I love it for that. Both of the new ones (leasing) I got her have been FLAWLESS in the fuctionional operation-within-design department. I only switched it out early for the extra 57 horses and other Jeremy Clarkson reasons.

 

[cd_booth]

Interrupting a regen every other time he drives it? I would think there would have to be something wrong with the car for this to happen.

My thoughts exactly. I have a similar commute to the OP's neighbor: 15 miles round trip, all city driving. I get on the freeway on the weekends and sometimes during the week but usually for an hour at the most.

I only have an interrupted regen a couple times a month at the most, less so in warm weather. I definitely agree that he should take it out for a freeway drive once or twice a week to see if it helps.

 

[slamhouse]

He's gonna be looking at a new turbo before 100,000 miles if he keeps interrupting regens on a regular basis.

If it's regenning when pulling into the driveway, let it idle until it finishes. No need to go out of your way on the highway during rush hour or anything like that - it will complete just fine at idle.

I strongly second this.

Just have him let it idle for about 10 minutes when he gets home every other day so it can complete its regen.

 

[Dozenspeed]

I can't say I'm content to merely let it idle the rest of the regen. From what I've learned from the oilhammer, it's really the resulted regen ash that clogs the dpf. The system is "closed" at idle to give it it's "clean diesel" properties meaning the ash has no chance to escape. I want to try my best to give it that chance by "blowing it out" with substanical rev driving.

Enlighten me if this is futile.

 

[JettaTDiPA]

I have interrupted regen in mine many times. Much like others, my car gets several short trips regularly. When I do interrupt- I plan on a 15 minute + highway drive within a day or two- (get engine to full temp prior to hopping on the highway)

It has been a complaint of mine for some time that VW did not put a regen indicator light in dash, other wise the running fans is often the only clue the operator gets.
Like many items on our cars, VW engineers failed to advise operator of a given function. Seemingly, if the dam thing just has to tell me when the temp drops to 38 degrees - it could certainly advise me of a regen

 

[> Luke <]

......... if the dam thing just has to tell me when the temp drops to 38 degrees -

it could certainly advise me of a regen

Point well made.....

 

[Turboneon1997]

its weird that regen goes on every day for him (15 miles is not that short of a commute to cause daily commute)
can you ask your neighbor how many miles on the car?
and when was the last oil change?
and was it doing regens daily before the last oil change?
if i understand correctly using incorrect oil could cause DPF to clog up and cause daily regens??

I did the last service on the car, with the proper oil and fuel filter. Also vagcom used on filter change. Car has 5xxxx miles

He's gonna be looking at a new turbo before 100,000 miles if he keeps interrupting regens on a regular basis.

If it's regenning when pulling into the driveway, let it idle until it finishes. No need to go out of your way on the highway during rush hour or anything like that - it will complete just fine at idle.

I agree, I suggested he go stage 2 with me but he isn't interested

I have interrupted regen in mine many times. Much like others, my car gets several short trips regularly. When I do interrupt- I plan on a 15 minute + highway drive within a day or two- (get engine to full temp prior to hopping on the highway)

It has been a complaint of mine for some time that VW did not put a regen indicator light in dash, other wise the running fans is often the only clue the operator gets.
Like many items on our cars, VW engineers failed to advise operator of a given function. Seemingly, if the dam thing just has to tell me when the temp drops to 38 degrees - it could certainly advise me of a regen

Very true

 

[tico27464]

OK - hope this isn't too much of a stupid question here - but can someone explain how interrupted regens shorten the life of the turbo? (FWIW, I drive lots of miles, mainly highway, and have experienced very few interrupted regens--just curious).
Thanks.
~T

 

[Jayg]

OK - hope this isn't too much of a stupid question here - but can someone explain how interrupted regens shorten the life of the turbo? (FWIW, I drive lots of miles, mainly highway, and have experienced very few interrupted regens--just curious).
Thanks.
~T

I'm guessing shutting off the car with a high egt can cause the oil in the turbo to coke up over time?

 

[TDI<wagen>]

^^ that would be my guess too.

I've noticed that fan also turns on when I am about to park the car after spirited driving. Although user manual tells about regen cycle, I think turbo has to be cooled off too. Otherwise, you are pretty much "cooking" your turbo.

 

[VeeDubTDI]

That is exactly the issue at hand - engine shutdowns at extremely high EGTs and thus extremely high turbocharger temperatures. Once you shut down, lube oil stops flowing and the oil that is stuck in the turbo's center cartridge will coke on the bearing, reducing its life.

The (neighbor's) car is trying to regen every day because it is behind on its schedule. Once he lets it complete, it will get back to the normal cycle of every few hundred miles. It may take a few times to get back on "schedule."

I think not having a regen indicator is similar to having a buffered coolant temperature gauge - more information is confusing to a large percentage of your average driver. I don't agree with this approach, but that is how VW has chosen to set these vehicles up. This is why Jason and I have a ScanGauge on our Passat - we know how to effectively interpret detailed information about the vehicle's operating conditions, as do many other enthusiasts on TDIClub. Unfortunately, ignorance is bliss for a lot of "appliance drivers."

 

[tico27464]

Thanks guys for the information re. the turbo/regen issue. Makes sense once I think to think about it. I can almost always tell when a regen is going on by the 'feel' of it, and of course once you shut down you can always tell if it is interrupting one (I'm fortunate this doesn't happen often to me) - but one more question: If one finds out one *has* shut the car off during a regen, is there any reason it would be bad to restart it and let it run throughout completion?
Thanks,
T

 

[engineered2win]

Either he has an issue or his DPF is loaded and he needs to complete a regen. There is absolutely no reason he should be having an active regen daily. That will cut his oil change interval down to a matter of a couple weeks due to fuel dilution in the oil reducing effective oil viscosity. Might the fan just be running from alot of low speed driving rather than an acutal regen? It isn't hard to figure out the difference, just sniff the exhaust when you get home.

 

[schultp]

.....That will cut his oil change interval down to a matter of a couple weeks due to fuel dilution in the oil reducing effective oil viscosity.....

How does having exhaust particulate trapped in the DPF effect the oil and allow fuel to mix with the oil? Sounds like I need a deeper understanding of the DPF. I had done some reading on how it functions but I am still new to the CR-TDI platform.

Is fuel used as part of the regen heating process??

TIA,

 

[OilBurningBrit]

How does having exhaust particulate trapped in the DPF effect the oil and allow fuel to mix with the oil? Sounds like I need a deeper understanding of the DPF. I had done some reading on how it functions but I am still new to the CR-TDI platform.

Is fuel used as part of the regen heating process??

TIA,

During an active regen, fuel is injected post-combustion (bottom dead center, I believe). This fuel is then pushed unburned out of the cylinders and is burned in the DPF to achieve the temperatures required for a regen.

Some of the fuel injected post-combustion will likely find its way into the oil. This happens more so with biodiesel, which is the reason for the 5% max bio content in the fuel for our cars - to prevent excessive fuel dilution of the engine oil.

 

[nickeasy]

There are two indications of a regen: Fans remain on after shut down and higher idle rpms. My Golf idles at roughly 9500 rpms during regen. Maybe the engineeers figure two indications are enough. And as I have heard in regards to Japanese bells and whistles, you don't have time to look at a bunch of gadgets when you are on the Autobaun!

Happy Thanksgiving

 

[OilBurningBrit]

My Golf idles at roughly 9500 rpms during regen.

Yikes!! That would be more than enough indication of a regen ... no need for an indicator light.

 

[schultp]

Some of the fuel injected post-combustion will likely find its way into the oil. This happens more so with biodiesel, which is the reason for the 5% max bio content in the fuel for our cars - to prevent excessive fuel dilution of the engine oil.

I am struggling to see how the fuel has more chance to get past the piston rings during a DPF regen compared to normal operation. I understand that it is injected post combusion and not burned but there is still a brief timeframe during each combustion stroke prior to combustion that the chamber is under maximal pressure. I would think that this would provide more opportunity for the oil to get past the rings compared to when the fuel is injected post combustion under low chamber pressure (I am assuming the fuel is injected immediately prior to the exhaust stroke).

Is there something I am missing? Seems to be a poor design if the fuel makes its way so quickly to the oil and dilutes it simply because of extra regen cycles over a short timeframe.

I am sure there is info I am lacking here to fully understand the process.

 

[kjclow]

My Golf idles at roughly 9500 rpms during regen.
Happy Thanksgiving

That should sound like a jet engine in your garage, especially since redline if around 6000 on these engines. Hope you meant 950. Although, I think mine usually bump up to just over 1000 during regen at idle.