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jdcaples
07-09-2010, 05:08 PM
This is related to thread: http://sprinter-source.com/forum/showthread.php?t=8337

I'll post the invoice and the part numbers when I'm able. For now, I'm just going to inform the forum of the following:

About three months ago, I started driving like a "normal" person, meaning putting the accelerator 1/2 to the floor when a red light turned green.

I drove in third gear at 40 miles per hour in the mornings for 3 months, M-F on the four mile drive to work, getting the engine up to operating temperature about 1/2 mile from my parking spot.

I continued using about 5% bio diesel, never exceeding 2.5 liters (0.66 gallons) per half tank.

I continued using TDR-S cetane booster at about 5 onces per half tank.

One day, on the way home from work, I couldn't get above 40 miles per hour and flooring it didn't help.

I scanned the Engine Control Module (ECM) with StarMobile and WiTECH 10.04.2 and it came back with DTC 2511 in the ECM. I kept the code, not clearing it and managed to stomp on it enough to make the code appear two more times. I kept all three stored codes for MB of Lynnwood to see (I hoped) with SDS.

I took it to MB of Lynnwood. I drove in at 3pm and they scanned my Sprinter about 20 minutes later. Diagnosis: failed EGR valve. They had one in stock. It was replaced the next morning.

It was replaced under warranty at no cost to me.

The best datapoint: MB Star Diagnosis System (MB SDS), their $27,000 scan tool returned the same code, 2511, that my $3,000 Chrysler scan tool returned.

At least for this, StarMOBILE doesn't "lie" like the Scangauge.

-Jon

PS: I asked about the cooler and the temp sensor. No warranty replacement at this time. They did not know how to inspect the cooler for fouling. It's a 5 hour job to remove and replace the cooler at $100.00 per hour and the cooler was a little less than $400 list price. With tax, it'd have been around $1,000.00 for what MB corporate would have considered "cosmetic, elective" surgery.

I'm ok with this for now because it's driving fine.

Oh, and I'm going back to driving like my old self again.

blackheart
07-09-2010, 05:34 PM
Had mine replaced at 15,000 miles once , all highway driving .
Same as you just went limp in mode on a hill.

15,000 miles all highway - not a good sign, was told a new style EGR valve was going on. Also did a ECM reprogram .

The reason they have them in stock is they go bad all the time and any shop will have them on hand to replace them when a customer comes in with a fouled one - which I am getting the feeling is often .


I try to never use bio diesel , pumps look all gunky at places that sell it, rather stick with regular diesel
YMMV

shanemac
07-09-2010, 05:44 PM
Jon, both our vans are very close in manufacture age and mine i think is do for a egr replacement as well. The egr recall was done when i had less than 10,000km(close to 40,000km now) i was hoping i would avoid egr issues because of the reprogramming and having it done early before i had alot of miles racked up....wishful thinking on my part.:hugs:

PS: I asked about the cooler and the temp sensor. No warranty replacement at this time. They did not know how to inspect the cooler for fouling. It's a 5 hour job to remove and replace the cooler at $100.00 per hour and the cooler was a little less than $400 list price. With tax, it'd have been around $1,000.00 for what MB corporate would have considered "cosmetic, elective" surgery.

Thanks for this info.

sailquik
07-09-2010, 06:37 PM
[QUOTE=jdcaples;99095]

At least for this, StarMOBILE doesn't "lie" like the Scangauge.

-Jon

Hi Jon,
Do you have and use a ScanGauge II?
I do not understand your comment the the SGII "lies".
I do not have an NCV3, but an '06 T1N 3500 with the OM 647 I-5 engine.
My SGII does not come up with precisely the same codes as Dr. A's DRB-III, but it does come up
with codes indicating the same issue.
In my case, my engine simply shuts off, I coast to a stop, and read the code. The SGII says I have another P2146.
This sets the CEL light on (it goes off after 3-6 start cycles).
I have to shift the trans to park to get the TCM (Transmission Control Module) to reset so the trans will re-engage.
Then I can start the van and continue with no issues...i.e. the CEL light is still on, but I know that the P2146
code means the Bank 1 Injector has a short or a current.
I put my DAD unit on the van and check for codes.... I get a consistent P2123.
If I visit Dr. A, and he does a full scan with his DRB-III, his diagnostic tools tell us it's a P2123 also.
So, in my experience, the ScanGauge II does not "lie", but rather it returns a code that is different, but
applies to the same components, so I know what is wrong.
Chrysler just changed my ECM (It's a PCM now, but the same part) and while the problem seems much
better, I have had one additional incident (P2146 per SGII.... P2123 per the DAD diagnostics unit.
To me, having the SGII to tell me what PCode is returned is a wonderful thing.
The real function of the SG-II (for me anyway) is the LOD readout.
Perhaps if you used LOD (% engine LOAD) as an important criteria when driving your NCV3, your EGR issue
would not have occurred as soon, or perhaps at all.
I'm not sure of this, just a suggestion.
Roger

jdcaples
07-09-2010, 08:28 PM
Hi Jon,
Do you have and use a ScanGauge II?
I do not understand your comment the the SGII "lies".
I do not have an NCV3, but an '06 T1N 3500 with the OM 647 I-5 engine.


Roger

Ok, so "lies" is a strong word, I admit...

This is what I mean:

SGII reports 2420 - which means:

EVAPORATIVE EMISSION SYSTEM
SWITCHING VALVE CONTROL CIRCUIT
HIGH

http://sprinter-source.com/forum/showthread.php?t=7792
http://sprinter-source.com/forum/showpost.php?p=63543&postcount=4

The actual code was 2511 which means:

Gas Recirculation Control Positioner Error

The numbers are different and the descriptions don't look equal to me. Maybe they mean the same to someone smarter than I.

-Jon

PS: we have different emissions equipment with an overly aggressive EGR cooler. Almost everyone I've spoken to about the NCV3 EGR system and cooler says it's an unfortunate design, doomed to foul itself into a non-working state. It's just a matter of time.

Regardless, I'll consider getting a SGII and driving by LOD after I foul the next EGR component.

PPS: on the chance a new person is reading Roger's post about about ScanGauge and DAD, the Dr. A Diagnostic (aka DAD) available today does not work on NCV3s.

HappyFamilyVan
07-09-2010, 11:01 PM
.... The egr recall....

Shanemac....by the EGR recall do you mean the H44 recall?...the ECM reprogram? I have an '08 and I do not remember EGR recall unless it was the H44. I had mine done with less the 100 miles in the odometer....I do not run bio, nor idle for long periods, and am near 20K miles...knock on wood....all seems fine....the only thing I notice is that the exhaust smells like bleach (swimming pool) after it has been running for awhile. I was not aware that the EGRs were a wear part. With the H44 recall, I was under the impression that they should not foul. I miss guided in my undersatning of the EGR?

shanemac
07-10-2010, 12:19 AM
Shanemac....by the EGR recall do you mean the H44 recall?

Yes that's right the reprogram H44.

Chandlerazman
07-10-2010, 01:10 AM
My exhaust has a similar bleach smell but a tad sweeter. Pleasant fragrance, I might add. Makes for loading stuff up more enjoyable :smilewink:

sprintguy
07-10-2010, 02:53 AM
Jon: sorry to hear that they wouldn't clean the cooler out while it was there.

I sit hear and chuckle at the reasoning behind not getting paid for it under warranty ( just cosmetic??? :thumbdown:) do people understand ROOT CAUSE OF FAILURE anymore ??? I mean, come on, WTF???? :frown: The ones that I cleaned the cooler out (or replaced) on never came back with an 2511 code after the surgery was done with a new valve replacement. As for "not being able to tell if it was all soot-ed up ... Just look at the valve, its a dead give away :idunno: Next time have them unplug the EGR temp sensor so you get the EGR cooler temp code (I forgot what number it was I think it was 2525 but not sure) That way the SDS's Quick test print out shows a "suitable failure " for warranty clean out or replacement. Soot + the overworked valve = sticky valve and 2511...

Rant over : Carl

Altered Sprinter
07-10-2010, 03:13 AM
Carl: is there a difference in the procedure defined by Dodge v Mercedes! As you have the advantage of working both sides of the spectrum.
This pops up regularly and with so many variations as to both inspection works being carried out in part or full, where some say No you can not clean the value successfully others say yes it can?
Can you clarify an exacting procedure,as to executing the preferred course to follow, for the said maintenance schedule.
Richard

jdcaples
07-11-2010, 04:51 AM
Description and part numbers attached. I was mistaken: it looks like I did get a new temp sensor.... just not a clean cooler.

The cooler part number stamped on my EGR cooler has been replaced with a newer part number. I do not know if that means it was redesigned. I may spring for the updated part - and its installation - myself.

Interested readers may cross-ref MB part numbers cited on my invoice with MOPAR part numbers at

http://starparts.chrysler.com/home/crossref.htm



-Jon

Düsseldorfer
07-12-2010, 05:38 PM
Description and part numbers attached. I was mistaken: it looks like I did get a new temp sensor.... just not a clean cooler.

The cooler part number stamped on my EGR cooler has been replaced with a newer part number. I do not know if that means it was redesigned. I may spring for the updated part - and its installation - myself.


Jon, I also got a new temp sensor with my last "EGR cooler spa treatment." It may be the case that cooler fouling causes temp sensor failure (implausibly high values, IIRC).

New EGR cooler part number, now that is interesting. Does the new one have a big inspection door in the side, so you can just pop it open, stick a terlet brush in there, and scrub-a-dub-dub?

D

jdcaples
07-12-2010, 09:49 PM
Someone's going to have to have an old part and a new part in front of a camera to figure out the difference. I strongly doubt, but won't know until I see one, that the new part is more DIY maintenance friendly because the entire motif of modern vehicles is to keep owners tethered to dealership service bays. That's not a bad thing if you lease or have the money to buy a new vehicle every 3 years or so, but that really doesn't work for me or a lot of us.

-Jon

PS: if anyone wants to volunteer to buy a new EGR cooler, I'd love to see a picture. Both old and new part numbers are available on EPC.startekinfo.com with the world passenger car and light transport subscription. The chassis is 906 and the engine is 642.993.

shanemac
07-12-2010, 11:53 PM
Does the new one have a big inspection door in the side, so you can just pop it open, stick a terlet brush in there, and scrub-a-dub-dub?


:lol:

Jon i took a snap shot of mine (original cooler), also mine still looks fairly healthy on the out side besides some dirt hear and there... not that it means anything i suspose...was thinking if cooler was getting plugged the outside may have over heating scars.

http://shane.servicetechhelp.com/egr%20cooler%20054.JPG

http://shane.servicetechhelp.com/egr%20cooler%20061.JPG

SPRINTERUK
07-13-2010, 11:50 AM
hi
the picture above from shane,s van part number has changed to a6421401375
sorry stock only in germany so no pics
the part number jon has had fitted is the latest part number
same with the sensor
if you want pics let me know
regards
chris

Chandlerazman
07-13-2010, 02:58 PM
So what is the main difference between the two coolers? passage space? I am almost at 26,ooo miles. So far no major issues but that may be due to my hard footed acceleration at times along with max rev passing modes I put my van through. I figure with enough exhaust gas movement, it will keep things somewhat clear.

SPRINTERUK
07-13-2010, 03:07 PM
i agree simon
i drive a ford mondeo 2 litre diesel euro 4
55.000 miles from new
once a week i give it some stick to clear out the egr valve after a puff of smoke it clears
last month i had to change a boost pipe so while i had it apart i cleaned the valve which was not to dirty after 55.000 miles
so maybe a little hard driving does help
my thoughts

chris

jdcaples
07-13-2010, 06:58 PM
New 642.993 EGR cooler part number - screen capture from epc.startekinfo.com

-Jon

IslandGuy
09-05-2010, 10:40 PM
Looks like I ran into the dreaded EGR semi-failure this afternoon on my way off of the Mukilteo ferry (locals know this route).
Headed up the pretty steep hill with my Winnebago View (2008 3500 chassis) and no power...MAP was 14.5 and top speed was about 30 mph. It finally shifted and I was able to pull of the road...shut down and waited a few minutes. On restart everything was fine...MAP was up to normal, as well as LOD...went on our way about 30 miles and everything was OK. Checked the scangauge and did not see any codes.
So of course we are on our way out to Forest City, IA for a Winnebago View/Navion rally...about 2200 miles. Have an appointment with Forest City Chrysler to get my oil and filters changed.

folzag
09-06-2010, 04:36 AM
About three months ago, I started driving like a "normal" person, meaning putting the accelerator 1/2 to the floor when a red light turned green.

I drove in third gear at 40 miles per hour in the mornings for 3 months, M-F on the four mile drive to work, getting the engine up to operating temperature about 1/2 mile from my parking spot.

Hello Jon, could you elaborate how you normally drive. My understanding was you typically drive really easy on the throttle. It was 3 months after you started driving hard on the throttle that the EGR fouled. Yet others have said taking the engine out to the highway every once in a while and giving it the old school burn-the-carbon-off-the-valves treatment has kept their EGR systems in good health.

So I'm a little confused... unless, I suppose, 0-50% throttle is not enough to burn the carbon. And I have a vague recollection you once saying normally you take a longer way to work so the engine has more time at operating temperature.

Thanks,
-Allan

jdcaples
09-06-2010, 04:42 AM
Hello Jon, could you elaborate how you normally drive. My understanding was you typically drive really easy on the throttle. It was 3 months after you started driving hard on the throttle that the EGR fouled. Yet others have said taking the engine out to the highway every once in a while and giving it the old school burn-the-carbon-off-the-valves treatment has kept their EGR systems in good health.

So I'm a little confused... unless, I suppose, 0-50% throttle is not enough to burn the carbon. And I have a vague recollection you once saying normally you take a longer way to work so the engine has more time at operating temperature.

Thanks,
-Allan

You're right. I didn't have a problem until I started driving "like a normal person."

I typically let the transmission shift at about 2000 RPMs through all gears. It takes me 5 to 8 seconds to get through a typical urban intersection from a dead stop if I'm first in line.

It takes me more than 20 seconds to go from zero to 60.

This is what I know: you stomp on an older diesel and you'll probably belch soot out the tail pipe (black smoke).

I drive my Spritner in a manner that I wouldn't vomit black smoke on the driver behind me if I were actually driving a 20 or 30 year old American diesel pick up.

-Jon

folzag
09-06-2010, 05:46 AM
"stomp on an older diesel and you'll probably belch soot out the tail pipe"

FWIW, that is from too rich a fuel-air mixture, though timing can effect smokiness as well. I'm less than 100% certain, but if memory serves severely retarded timing is black, severely advanced timing is white.

For electronically controlled fuel pumps, it is trivial to limit the fueling based on the manifold pressure and RPM. That's called the AFC, air-fuel controller. It is a 1-dimensional limiter curve. There's also the Torque curve, also 1-dimensional. That is placed by marketing and warranty considerations. In fact, the heavy, off-highway engines would have an ALT-Torque switch that could temporarily (10 minutes, once every 60 minutes? I'm not sure, I didn't do much off-highway controls) give the operator a few extra horsepower to get himself unstuck or whatever.

Then there's the throttle control. It's either ASG (all speed governor) or open-loop fueling. The ASG was always my preference, the pedal position translated to an engine speed request, kind of like cruise control for RPM. That's popular on tractor trailers. The open-loop fueling is just a pedal position translated to a fueling percent. This mimics the old gasoline carburetor engines where the pedal directly controlled air-flow: more air, more fuel. If cruise control is engaged, software choose max between the cruise control loop and the throttle pedal: you want the driver to be able to out-run the cruise and the cruise to out-run a foot off the pedal.

Finally, there's the emissions and turbo limiters. Those can be complex PID control loops or simple 1-D look-up tables like AFC & torque curve.

Among all these inputs, the software chooses the least and that becomes the output sent to the fuel-system specific part of the software that drives the actuators on the fuel pump hardware that give one the physical fueling and timing.

Oh, timing. Timing is it's own completely separate control loop based on engine speed, engine temperature, air temperature, manifold pressure, and probably a couple other things I've forgotten.

Anyway, that's largely why modern diesels are neither smokey nor smelly nor loud (noise is affected by timing most of all). Hope folks found it useful. :-)

nikolay0630
09-06-2010, 04:56 PM
I also was dealing with EGR issue, I guest. I went to local MB North Miami, FL.
There diagnose sheet states: check engine light on from a sensor being faulty…..2853, 3130, 2951. Also DAS says, when this sensor goes bad to remove the EGR Cooler inspect and clean…that would be an additional 5.5 hours and coolant for $25.59.
I bought the temperature sensor A 007 153 84 28 and have changed it by myself, because dialer priced me out $304.92+tax and 2.0 hours labor:yell:. I got it for about $130 and changed in 5min. unfortunately, my check engine light is steel on:idunno:
But the main reason I went to MB dialer was to check my a/c. I’m in South Florida and without a/c, I’m dying:cry::cry::cry:. My a/c was weak, since a day one. Dodge dialer had check and diagnose the issue so many times, but no big change. Now MB states:
The a/c is having a faulty refrigerant control valve (9601 ), which is part of the compressor $995.00 receiver dryer $53.75, Freon $11.52 each and needs 4, compressor oil $53.75 total labor 4.0 hours with the diag and that’s it unless the compressor came apart and started to damage anything, I won’t know until the compressor is removed…
The 9601 fault cote is refrigerant compressor control valve circuit low. I negotiated a bit and dialer can do the a/c compressor for $1318, but they can’t promise that will solve the issue. I don’t know what to do…..:idunno:
My a/c is working ok mostly on highway driving (not every time), but when is too hot and especially in stop & go traffic – doesn’t work at all. My first guess was, there isn’t enough cooling…..I do have only one fan at front (like Jon, but he had install one). Do you guys thing I can add a second fan first and see the result or I have to change the compressor? I have no idea!!!
I believe, the compressor isn’t bet, cause when it's working it blows cool air pretty well. I don’t know anything, about the refrigerant compressor control valve!!!:idunno:
Is it really part of the compressor?
Sorry, I changed the subject, but the a/c is bugging me a lot …. Especially in Florida

jdcaples
09-06-2010, 05:27 PM
Well, I'm willing to consider that the EGR problems I encountered after driving like a normal person was just not related: all the fuel I didn't fully combust, operating conditions (low heat, low RPMs etc) made a coincidental collision on the calendar.

I'll ponder this for a bit.....

-Jon

folzag
09-06-2010, 06:02 PM
After writing that up and sleeping on it, it occurred to me the real question is what causes the EGR to engage? While I actually wrote a fair amount of EGR software, I never really paid attention and understood what the systems guys were doing with it. I just coded up the control loop they asked for and sent it to the test cell. At the time EGR was thoroughly uninteresting to me -- stupid EPA ruining performance was all I could see.

Anyway, there's a few things going on that are going to effect EGR fouling. First and foremost, what causes the EGR to open? An once of prevention and all, it's best if one can drive in such a way that the EGR does not even open. That's probably impossible, but perhaps a worthy goal to aim for (call it the jd method :bounce:). Next question is once the exhaust gases start re-circulating, what makes them foul the valve and cooler? The third question is can one "clean out" the valve and cooler by fully opening the valve and blasting hot exhaust through it for a period of time (the chandlerazman method :smilewink:)? If so, how best to induce that state? Finally, do environmental conditions have an effect? Is the hot, dry ambient air in AZ inherently less fouling than the cool, damp air in the PacificNW?

It been over 10 years since I wrote diesel engine controls. I've about forgotten the name of the guy that I worked with on EGR, and have no idea if he's still at the same company. I'll start thinking about it and see if I can come up with his name and email. He was always an interesting guy and would probably be able to speculate quite well the answer to all these questions.

folzag
09-06-2010, 06:14 PM
Ha! I got it. Paul Miller. (Sometimes I amaze myself :lol:) Wow, seems he's doin' quite well (http://www.cummins.com/cmi/content.jsp?siteId=1&langId=1033&dataId=2896&newsInfo=true&menuId=4).

Also recognized with a Perr award was the team of Paul Miller and Chuan He that invented an equivalence ratio-based system for controlling transient fueling in an internal combustion engine.

This invention, also known as oxygen/fuel control, met the goal of creating a fundamentally and physically sound basis for transient particulate matter (PM) emission control, while facilitating robust oxides of nitrogen and PM emission compliance with exhaust gas recirculation (EGR) technology. EGR technology is at the heart of emissions control for many of Cummins’ diesel engines used in on-highway applications.

The benefit has been a consistent emissions control method over multiple product cycles with no need to reinvent, even as engine air handling, combustion and aftertreatment system architectures have evolved considerably since the original invention.

jdcaples
09-06-2010, 06:27 PM
I'd need a co-pilot to watch and record EGR valve actuation using WiTECH PC software and my StarMOBILE unit.

This tool combination will show EGR valve actuation through-out the driving cycle, but I'm not going to watch a laptop while driving.

If the co-pilot were also an NCV3 driver (and if I trusted that person with my Sprinter), we could swap roles and see what my Sprinter's EGR valve metrics are when driven like a normal person.

As of late, I'm kind of busy most hours (when I'm working) and afflicted with lazy/lethargic demeanor in others (when I don't have to be anywhere, I don't feel like going anywhere or doing anything).

I'll need to be motivated to execute this experiment. I can't think of another way to verify the notion that my driving style results in less exhaust gas recirculation than other driving styles.

While this discussion hasn't gotten me off my keister - by a long shot - I admit there is a smidgen of inspiration.

-Jon

Chandlerazman
09-06-2010, 06:47 PM
Keep in mind that our speed limits outside the Phoenix metro area on certain highways/freeways are posted at 75. It is not uncommon to exceed that which is why perhaps my EGR is still hanging in there. I don't expect it to be foolproof and replacement will be necessary sometime. Cruising at the governed limit may help in keeping the exhaust gasses flowing when going desert crossing. I wonder about the comment regarding cooler damp air as a factor in failure. This is a very good and valid point brought up by Folzag. Perhaps at each startup when gas temps are low, a very thin film is deposited?

folzag
09-06-2010, 06:58 PM
While this discussion hasn't gotten me off my keister - by a long shot - I admit there is a smidgen of inspiration.

Jon, you never fail to crack me up.

folzag
09-06-2010, 07:00 PM
I wonder about the comment regarding cooler damp air as a factor in failure.

I bet the warranty bean-counters at all the major engine manufacturers could answer this.

flman
09-06-2010, 08:30 PM
:lol:

Jon i took a snap shot of mine (original cooler), also mine still looks fairly healthy on the out side besides some dirt hear and there... not that it means anything i suspose...was thinking if cooler was getting plugged the outside may have over heating scars.


Thanks for the pics, I was wondering what those finned devices near the Exhaust manifold were for? Has any one with a 2010 had EGR failure, or can I expect better mileage being things have improved?

flman
09-06-2010, 09:18 PM
I was wondering if we were to block off this pipe with the green on it, would it cause a DTC? No exhaust gas going through the EGR, means no soot to plug it up, plus no soot mixing with the CCV fumes to create a manifold gunk build up either?

http://i958.photobucket.com/albums/ae67/flman2001/Sprinter/IMAG0178.jpg

jdcaples
09-06-2010, 09:36 PM
I was wondering if we were to block off this pipe with the green on it, would it cause a DTC?

I'm not going to do it just to prove or disprove my guess but:

2355 - Exhaust Gas Recirculation Rate is too Low
3152 - Exhaust Gas Recirculation not Active
3151 - EGR flow monitoring of Air Mass is Faulty


Let me know if you do it, but please have an NCV3-appropriate scanner handy and not just consumer-grade ODB generic scanner. Many DTCs won't illuminate the NAFTA NCV3 check engine light or any other instrument cluster message. Consumer grade ODB scanners are not capable of understanding the full lexicon of NAFTA NCV3 DTCs.


-Jon

cedarsanctum
09-06-2010, 10:05 PM
I'd need a co-pilot to watch and record EGR valve actuation using WiTECH PC software and my StarMOBILE unit.

This tool combination will show EGR valve actuation through-out the driving cycle, but I'm not going to watch a laptop while driving.

If the co-pilot were also an NCV3 driver (and if I trusted that person with my Sprinter), we could swap roles and see what my Sprinter's EGR valve metrics are when driven like a normal person.

As of late, I'm kind of busy most hours (when I'm working) and afflicted with lazy/lethargic demeanor in others (when I don't have to be anywhere, I don't feel like going anywhere or doing anything).

I'll need to be motivated to execute this experiment. I can't think of another way to verify the notion that my driving style results in less exhaust gas recirculation than other driving styles.

While this discussion hasn't gotten me off my keister - by a long shot - I admit there is a smidgen of inspiration.

-Jon
Jon,

Couldn't you run a graphing program on the computer, maybe timed with a video for comments, that would record those specs as you drive?
Just thinkin'.
And very curious about the outcome of such experiments. This is an approach i have been thinking of for many miles of driving, when does EGR actually activate, and can it make a difference trying to second guess that?
Gut sense is it won't make much difference, or won't give any useful info because of the number of variables available.
Maybe not worth the time, or a true challenge?

Have Fun
Jef

folzag
09-06-2010, 10:27 PM
And very curious about the outcome of such experiments. This is an approach i have been thinking of for many miles of driving, when does EGR actually activate, and can it make a difference trying to second guess that?
Gut sense is it won't make much difference, or won't give any useful info because of the number of variables available.

Actually, my guess is that it would be reasonably easy to reverse engineer the EGR actuation. I doubt it's modeled on more than two variables. Circumventing them might be tough... ie. either the engine is at operating temp or it's not, but if you gotta drive, you gotta drive... but knowing when it's most likely active is knowing when you're best served driving exceptionally easy.

I do think the many reports of fouling from excessive idling is a big clue. NOx results most heavily during lean burn conditions. Lean burn is mostly an idle condition. If you want to minimize EGR, perhaps minimize lean burn.

If there's anyone with SAE access, I bet there's more than a few papers out there on EGR research. I bet they all deal with the same 2 or 3 input variables and just discuss different ways of responding to and acting upon those variables.

autostaretx
09-06-2010, 11:12 PM
I was wondering what those finned devices near the Exhaust manifold were for?
If you mean the stuff just to the right of your green markings, they're not fins, they're corrogations to allow mild bending of the pipe during installation.
They allow the two gadgets the pipe connects between to be mildly mis-matched, and the act of tightening down the flange bolts will bend the pipe in the corrogated area.

--dick

folzag
09-06-2010, 11:20 PM
The first 15 pages or so of this paper (http://etd.ohiolink.edu/send-pdf.cgi/Haber%20Benjamin.pdf?osu1274191066) has a very nice introduction to diesel engine emission technology. Reading between the lines, you can also see why idling is so bad from an EGR stand-point. Idle is low-boost and low temperature. That's when NOx formation is most active and it's also when EGR makes the most difference. Thus, if you want to minimize EGR, minimize low-temp idle and keep the boost up. Um, not coincidentally, that's what the high speed idling achieves.

A few excerpts:
The NOx will primarily form in local areas that are near or slightly below
stoichiometric conditions, which allows for higher temperatures. While the cylinder
temperature remains high enough the NOx that has formed will begin to disassociate back
into nitrogen and oxygen. This only occurs at a noticeable rate until the predominant part
of the expansion stroke is reached and the mean temperature of the combustion chamber
drops with pressure. When this happens the disassociation will cease and concentrations
of NOx freeze at their present value. Hastening the cooling of the NOx molecules is the
mixing between the high temperature zones with the rest of combustion chamber.

Ie. a cold engine is going to need more EGR, as more NOx is being formed.

Low Temperature Combustion works by using extensive amounts of EGR to
reduce emissions. EGR is able to reduce emissions both because of its ability to reduce
peak temperatures, and by extending the mixing and evaporation time of injected fuel. A
reduction in peak temperature regions, normally above 2200 K, directly reduces NOx
formation to near negligible levels. Particulate matter will normally increase with EGR
until it reaches the high rates of LTC, on the order of 55%, where there is a sharp
decrease in PM formation
Ie. EGR in a cold engine is going to have higher soot/fouling content.

folzag
09-07-2010, 12:30 AM
I'd need a co-pilot to watch and record EGR valve actuation using WiTECH PC software and my StarMOBILE unit.

This tool combination will show EGR valve actuation through-out the driving cycle, but I'm not going to watch a laptop while driving.


Just had an interesting thought.

Map the EGR actuation vs engine speed with the vehicle in Park. Do it after 1-2 minutes of warm-up, and again after the engine has reached full operating temp. I wonder if there's a sweet spot where we see the valve open and close? It probably has some hysteresis so you would want to look at both ways: going up in RPM to see if there's some point the valve closes; then once closed, slow the engine down to see where it opens back up. In addition to coolant temp, (and probably more importantly) you'd want to capture MAP and intake temp.

I bet the factory high idle set point that's been discussed on other threads closes the EGR, at least if the engine is warm and the intake temp is high enough.

flman
09-07-2010, 01:32 AM
If you mean the stuff just to the right of your green markings, they're not fins, they're corrogations to allow mild bending of the pipe during installation.
They allow the two gadgets the pipe connects between to be mildly mis-matched, and the act of tightening down the flange bolts will bend the pipe in the corrogated area.

--dick


I meant the picture on page 2 of this thread, not the corrugated pipe.

cedarsanctum
09-07-2010, 03:25 AM
If you mean the stuff just to the right of your green markings, they're not fins, they're corrogations to allow mild bending of the pipe during installation.
They allow the two gadgets the pipe connects between to be mildly mis-matched, and the act of tightening down the flange bolts will bend the pipe in the corrogated area.

--dick
Those corrugations also allow the metal to expand and move when it gets hot without breaking things apart.

IslandGuy
09-10-2010, 02:58 AM
Update on my loss of power issue...on my way to Forest City, IA and continued to have loss of power issues. We were 5 miles outside of Livingston, MT at a rest area and had the loss of power issue happen again. I knew that there was an authorized Sprinter dealer in Livingston...Yellowstone Country Motors Chrysler. We stopped in and within an hour I was back on the road with a new EGR valve installed under warranty. These guys are fantastic. The tech told me the EGR threw all kinds of codes, none of which the Scangauge picked up, and the EGR was replaced. End of story! If you ever happen to be in MT and need service these are the guys (the only ones) to see!!

jdcaples
09-10-2010, 01:18 PM
That's good to read, Islandguy.

I'm going to close this thread because I think it's run its course and we can end on a good note, too :)

-Jon