2009 TDI exhaust regeneration

Has anyone had this happen yet? If so what happened?

Keep in mind that there are three different regeneration cycles that operate at different frequencies.

The normal regen of the de-NOx catalyst happens on a time scale of every few minutes, so I guarantee that anyone who has taken delivery of a 2009 and has driven it further than the dealer's lot to home, has had this happen.

The DPF regen is supposed to happen order-of-magnitude every 1500 km. DPF regen results in very high exhaust temperature, but shouldn't be noticeable to the driver.

On a much less frequent basis occurs a de-sulfurization of the de-NOx catalyst. I would expect that this is going to make the exhaust stink like sulfur for a few minutes.

None of these are supposed to be noticeable to the driver.

GoFaster said:

On a much less frequent basis occurs a de-sulfurization of the de-NOx catalyst. I would expect that this is going to make the exhaust stink like sulfur for a few minutes.

Click to expand...

That's where the H2S catalyst as the last part of the exhaust aftertreatment is there to deal with.

The design of the exhaust line for the Volkswagen application is depicted in Figure 2. A diesel particulate filter (DPF) with a small upstream catalyst is located close to the engine. Both devices share the same canning. The important NOx-reduction device is located in underfloor position followed by a small catalyst which eliminates secondary emissions,
such as H2S which can be formed over the underfloor LNT during desulfation events.

Click to expand...

Göbel et al. Diesel NOx-Aftertreatment Systems for North America. 29. Internationales Wiener Motorensymposium 2008.

TDI exhaust system for T2B5

DB

is it me or does that look like a big restrictive mess.

While producing 140 HP (4000 rpm) / 320Nm (1750-2500 rpm) and consuming as low as 204 g/kWh at it's best efficiency and still meet Tier II Bin 5, it can't afford to be restrictive otherwise emissions would go up and fail emissions requirements!

The system to insure it remains UN-RESTRICITIVE uses multiple pressure sensors to insure the lowest restriction during operation. Burn-off cycles can be triggered by increased back pressure (restriction) so the engine will increase EGT's and clean out the blockages returning the system to a it's original free flowing condition.

DB

Hmmm seems like the system is more transparent than i thought then, i think i've mentioned it before, but the trucks we have at work when they go through an actual regen ( just had one the other day) it goes into lock down u can't drive it and u sit push a parked regen button, the engine revs go crazy exhaust spits out uber hot fumes, whole thing takes about 20 mins. A passive regeneration happens at highway speeds obviously but i wouldnt' even call that a regeneration just optimal burn. Would be curious if it would be anything similar.

Trooper 81

What truck engine are you referring to?

John

jvc said:

Trooper 81

What truck engine are you referring to?

John

Click to expand...

internationals we have at work

Drivbiwire said:

TDI exhaust system for T2B5

DB

Click to expand...

Wow!

I wonder how much it will cost when something in that system goes bad. Say, like a sensor or something, and god forbid that exhaust valve should take a crap.

That's assuming someone will be able to fix it?(dealer)

Drivbiwire said:

TDI exhaust system for T2B5

DB

Click to expand...

Has anyone looked at the warranty coverage on any of this? What does it read like?

I'll have to dig out my warranty again, but if I'm not mistaking, the particulate filter is only covered for 24 months... don't recall if it made a statement regarding the rest of the system.

Wes

For Gosh sakes please don't quote large pics

Yea all the wondering and guessing at the restriction is kind of moot.

Who cares what it looks like, but it does look stout and well made. We know it works well and they are getting good gas milage. 7 sensors and 4 catalytic converters and a servo contolled exhaust valve.....cool.

We also know the new TDI is super eco friendly, sunflowers grow at the side of the road instantly as you dive by, with a rainbow in the sky as butterfly's beat their wings in the air. Price less.

Sensors are ALL OVER current cars and already have DPF's and catalytic converters. This just has an extra one? The other part of the magic not shown is the piezoelectric injectors and the ECU which is more sophisticated.

Some one above or another thread said the NSC (NOx Storage Cat) estimated life or routine maintence was est. at least 120k. For me that is 12 years or more of driving (pls don't write you do that in a year, u-da-man ok). Cost of replacement part is unknown. Look GREEN is not free.

The emission should be under the power train warranty? 5 yr/ 60,000 mile. (I recall some one said 80k on emission but not sure.)

The question is whether the UREA injection method of reducing NOx is cheaper. I know they are not catalytic or sensor free either. In 5 years we will see if there is any shake out of the new technology or issues. It's all new. I suspect most of the problem will be with owners and VW dealer service not the design or components.

Also as an owners of the '09 and later will not know you have a problem until you start to not pass emission test or the check emission light glows. It remains to be seen what will goes first, when and what it will cost. I suspect it will give 5-15 years of trouble operations. So if a new converter cost $100 or $1000, that is the cost of doing green business.

If you live in a state with out strict emission inspections you might not be forced to repair the after-treatment. Who knows how it will run when the catalytic stuff shot or removed. I would say that is not cool, but people take off emission stuff all the time; if you can't afford to maintain it may be you should own a different car.

We just don't know and I suspect it will be a success and any griping will be jealous people who can't afford one.

Revolutionary_mind said:

is it me or does that look like a big restrictive mess.

Click to expand...

"Restrictive" is a buzz word used by aftermarket exhaust peddlers, nothing more. Real engineers have things under control.

As an engineer, I blush.

TDIMeister said:

As an engineer, I blush.

Click to expand...

Blush my ass, in the test cell with the 140hp/liter Diesel BMW you grew horns and developed an evil grunt like Dr. Frankenstien!

LOL
DB

invader said:

Wow!

I wonder how much it will cost when something in that system goes bad. Say, like a sensor or something, and god forbid that exhaust valve should take a crap.

That's assuming someone will be able to fix it?(dealer)

Click to expand...

Not shown in the system picture is that it is put together using V-band clamps. The valve assembly in my estimation would be a 5 minute swap out (if you REALLY took your time). Sensors are no more unreiable than the O2 sensors in the BEW and BRM TDI's...when was the last time those went bad?

Pressure sensors in the exhaust have been used now for over 5 years in the CRI-3 TDI's (MB CDI) never heard or seen of issues in those.

Even if the sensor is bad, unscrew the sensor, apply high temp nickel anti-sieze and reinstall.

In regards to longevity, the key to durability and life of these systems is reducing the amount of sulfur compounds. Proper oils (LowSAPS VW507.00), less than 10ppm sulfur fuels all lend to longer than expected life.

Of course this now sets up the path for GTL and eventually Bio-GTL fuels with 0ppm sulfur

2011 marks the transition of the US Air force to 50% home brewed GTL providing aircraft and diesel needs, point it is coming!

DB

What does the way down stream exhaust valve do?

I gather it has something to do with Regen of the DPF or NSC or DOC?

The N2S Cat is hanging off the end. I guess no Regen or sensors needed. Those are a lot of Cats. May be in the future they will put all this in one big magic box.

How does it work and why? You would not expect something to restrict flow in the mix but as was implied, back pressure is a bit overused hype to sell things or not a totally bad thing. Back pressure can be tied to "scavenging".

Does it still have EGR?

I would have hoped they would take exhaust for the EGR from behind the cats and put it in pre turbo, but clearly that's not shown. To this point the messiest job I have done on a car is cleaning the intake at 170K on a TDI.

Ohhh yes ... There are TWO EGR systems, including a low pressure system that takes the EGR after the DPF (which should thus never clog). And the high pressure one no longer has an EGR cooler. I think they have applied some lessons learned here.

The other current thread has some words about how this system works.

http://forums.tdiclub.com/showthread.php?t=223301

just an note..PZEV cars have 15 year 150000 mile emmissions warranties by federal law

I don't think the TDI is PZEV. Close, but not quite. I think they have to be Tier 2 bin 2 for that.

Does anyone know for sure about the warranty? One thread stated the DPF only has a 2 year warranty. New technology is fine and dandy, but not if the warranty expires and then something goes wrong.

There's an interesting article in this month's issue of Diesel Progress (September 2008). Mostly about Cummins' decision to reverse course and pursue urea-SCR for NOx control for their 2010 HD diesel line (the decision is mostly based on improved fuel economy of urea-SCR over NAS - about 5%).

However, the article states that Cummins expects to be able get engine-out PM low enough that DPF regen will be exclusively passive (i.e., no fuel required for active regen). Wonder if that's possible with light-duty diesel engines?

trouble with passive regen is that it depends on driving patterns. The DPF retrofit kits that were put into effect for European consumption were passive regen only, and if you didn't at least occasionally drive the car hard enough and for long enough to initiate a regen, they would clog.

Trucks tend to be relatively underpowered relative to cars (take a look at the power to weight ratio!) so the engine has to work harder, relatively speaking.

I would like to hope the emissions warranty is 7 years. It always has been.

weedeater said:

I would like to hope the emissions warranty is 7 years. It always has been.

Click to expand...

I'll dig my owner's manual out again, but I think it's actually LESS that the total cars 36/36.. I believe it is two years.

And also, the particulate filter is scheduled for change at 120K.

Wes

GoFaster said:

trouble with passive regen is that it depends on driving patterns. The DPF retrofit kits that were put into effect for European consumption were passive regen only, and if you didn't at least occasionally drive the car hard enough and for long enough to initiate a regen, they would clog.

Trucks tend to be relatively underpowered relative to cars (take a look at the power to weight ratio!) so the engine has to work harder, relatively speaking.

Click to expand...

I ran some numbers once... the power-to-weight ratio of the average bus at work is such that to be matched in a car, your Jetta TDI would need to be powered by a humble 28 horsepower diesel.

And yet we cruise and merge and roam just fine...

proper distance to drive?

OK, I'm starting to get nervous when I read posts on this forum that suggest one has to drive more than 20 or 30 miles at one time frequently in order for components of the emissions system to adequately regenerate. Are these claims true? Do the owner's manual of people who have already taken delivery say anything about this?

Sometimes I go days w/o driving my car at all. I live across the street from my workplace. When I do drive, it's generally between 5 - 15 miles one way with the occasional (1x per month) more than 1 hour road trip. I put on between 10-12 thousand miles each year.

I am not the typical mid-long distance commuter. Does anyone think this will be a problem?