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      02-16-2014, 11:34 AM   #89
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If the 335d isn't a big enough load for the inline6, would adding weight (like sand bags ) make a meaningful difference in load? How much would be meaningful if it could be done with out damaging something else???
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      02-16-2014, 12:02 PM   #90
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Originally Posted by Big_Daddy_38 View Post
If the 335d isn't a big enough load for the inline6, would adding weight (like sand bags ) make a meaningful difference in load? How much would be meaningful if it could be done with out damaging something else???
You are asking this hypothetically, not actually intending to do so, correct?
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      02-16-2014, 12:27 PM   #91
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It is a serious question. Maybe not a serious solution though. How might the load be increased and to what extent would it have to be increased to make a difference without hurting something else. I understand economy would be decreased in any load-increasing activity.
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      02-16-2014, 04:12 PM   #92
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Originally Posted by Big_Daddy_38 View Post
It is a serious question. Maybe not a serious solution though. How might the load be increased and to what extent would it have to be increased to make a difference without hurting something else. I understand economy would be decreased in any load-increasing activity.
Fair enough. For the sake of conversation...
335d. 3825 lbs. 275hp.
X5 35d. 5192 lbs. 265hp

So you could add 1400 lbs worth of sand bags if you want the x5s performance/weight, but this would obviously greatly exceed the e90s max weight, decrease fuel economy and performance, etc. You'd likely be much better off just pushing it harder each time you're out if you want to increase the engines exerted effort, but you're never going to incase the load that much on public roads.
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      02-16-2014, 08:30 PM   #93
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All this talk of "driving it like you stole it" is BS IMO.

I have 4000 miles tracked with Fuelly and I am barely over 30 MPG. Figure it out.

I drive the vast majority of those miles on the highway.

In other words...within the limits of sanity...and with the help of $2500 in CHP Defense...I am putting as much "load" as can be reasonably expected.

If I experience carbon build up, then ANYONE can.

Only time will tell.

It is unreasonable to expect that the average consumer would drive like I do.
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      02-16-2014, 08:44 PM   #94
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Originally Posted by daveN007 View Post
All this talk of "driving it like you stole it" is BS IMO.

I have 4000 miles tracked with Fuelly and I am barely over 30 MPG. Figure it out.

I drive the vast majority of those miles on the highway.

In other words...within the limits of sanity...and with the help of $2500 in CHP Defense...I am putting as much "load" as can be reasonably expected.

If I experience carbon build up, then ANYONE can.

Only time will tell.

It is unreasonable to expect that the average consumer would drive like I do.
I can't say I subscribe to it, but time will indeed tell.
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      02-16-2014, 09:09 PM   #95
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Originally Posted by daveN007 View Post
All this talk of "driving it like you stole it" is BS IMO.

I have 4000 miles tracked with Fuelly and I am barely over 30 MPG. Figure it out.

I drive the vast majority of those miles on the highway.

In other words...within the limits of sanity...and with the help of $2500 in CHP Defense...I am putting as much "load" as can be reasonably expected.

If I experience carbon build up, then ANYONE can.

Only time will tell.

It is unreasonable to expect that the average consumer would drive like I do.
I agree. Anyone who takes the time to troll around these boards is probably not driving their 335d like grandma. Believe me I have nothing but contempt for people who don't drive these cars the way they were meant to be driven, i.e., fast. That said, we wouldn't be talking about these problems if it was just a matter of flooring it. If I get 30+ mpg per tank I feel like I have done something wrong.
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      02-19-2014, 04:16 PM   #96
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My SA mentioned that they are seeing an increased frequency of 335D and X5D in for head cleaning. It appears that the X is in the cross hairs too.
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      06-13-2014, 07:07 AM   #97
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Flooring 425ft/lbs all the time during city driving isn't best idea either. The real fix is to not have the exhaust gasses recirculated to begin with...
Very true, I laughed when I read this, JUST FLOOR IT ALL THE TIME, thru schools zones, In a 25 mpg zone, at every stop light, lol...
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      06-13-2014, 09:40 AM   #98
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Looking at TDIwise's logging of EGR usage, it appears that EGR is highest at partial "throttle", light loads. EGR is off when coasting, idling, and higher engine loads.

Seems like highway miles would cause the most EGR. Stoplight to stoplight driving would use the least EGR. (especially when driving "spiritedly")

Anecdotally, people driving lots of highway miles seem to delay CBU. Could it be that the larger component causing CBU is coming from the PCV oil mist? Maybe more oil is generated in the intake tract with stop and go driving?
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      06-13-2014, 10:52 AM   #99
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Originally Posted by Crawler View Post
My SA mentioned that they are seeing an increased frequency of 335D and X5D in for head cleaning. It appears that the X is in the cross hairs too.

I was told this as well. Seems as thought the X is getting shitted on just like we are. Come on BMW, accept this as a known problem and put out a SIB or recall on the CBU. It's the right thing to do.
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      06-13-2014, 10:59 AM   #100
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Originally Posted by nuclearbeef View Post
Looking at TDIwise's logging of EGR usage, it appears that EGR is highest at partial "throttle", light loads. EGR is off when coasting, idling, and higher engine loads.

Seems like highway miles would cause the most EGR. Stoplight to stoplight driving would use the least EGR. (especially when driving "spiritedly")

Anecdotally, people driving lots of highway miles seem to delay CBU. Could it be that the larger component causing CBU is coming from the PCV oil mist? Maybe more oil is generated in the intake tract with stop and go driving?
Highway driving changes the miles/engine hours ratio, so maybe CBU is better represented by logging engine hours.

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      06-13-2014, 12:59 PM   #101
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Originally Posted by modobrew View Post
I was told this as well. Seems as thought the X is getting shitted on just like we are. Come on BMW, accept this as a known problem and put out a SIB or recall on the CBU. It's the right thing to do.
This has been done. Many EGR recalls and an SIB on intake clean up have been released. Issue is caused by low fuel quality allied with very tight NOx emissions limits in US.

All the discussion about alternatives to stop CBU are measures to throw in the atmosphere the un treated diesel burn by products. They are all against the law.

The reality is: all direct injection engines require carbon build up removal as preventive maintenance. With the low grade US fuel some applications will require a smaller interval between clean ups.
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      06-13-2014, 01:32 PM   #102
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Originally Posted by Jffeijao View Post
This has been done. Many EGR recalls and an SIB on intake clean up have been released. Issue is caused by low fuel quality allied with very tight NOx emissions limits in US.

All the discussion about alternatives to stop CBU are measures to throw in the atmosphere the un treated diesel burn by products. They are all against the law.

The reality is: all direct injection engines require carbon build up removal as preventive maintenance. With the low grade US fuel some applications will require a smaller interval between clean ups.
It is my belief that overly strict NOx emissions requirements are due almost exclusively to the Los Angeles Valley in California being such a "smog trap" as there is evidence that during Native American times, smoke from fires would literally darken the air in the valley.

As a result of ignoring diesel engine advantages in all other aspects of air pollution, including small particulates as it turns out, we are saddled with a poorly conceived and executed public sanction against diesel engines. The lack of spine many politicians have against ill thinking environmentalists has arguably contributed to pollution and CO2 emissions more than if diesels had not been forced to comply with regulations designed for gasoline vehicles.

Removing our ability to cut NOx emissions would hardly make a difference, but if the tuning is right, could improve other aspects of diesel emissions now harmed by the poorly conceived regulations.

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      06-13-2014, 01:32 PM   #103
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      06-13-2014, 02:46 PM   #104
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Originally Posted by Jffeijao View Post
All the discussion about alternatives to stop CBU are measures to throw in the atmosphere the un treated diesel burn by products. They are all against the law.
the idea that NOx from passenger car diesels has any impact, whether lessened by EGR or not, on the environment is ludicrous. The 335d as rated in CA registered 0.00g/mi of NOx at highway speed. Now, thats probably something like 0.001 or something greater than actually 0, but the fact that you remove the EGR is not going to automatically put you into 1970 merc diesel territory. As stock the 335d is significantly less "polluting" on the highway than a prius. By deleting the EGR, you might instead put your d into the range of a 4 cyl Chevy Cruz

Accepting CBU as a fact of life is the same attitude that would have left us stuck with 175 HP 5.7L V8 cars getting 12 MPG instead of the 390HP 5.7L trucks getting 20 MPG that we have now. There is always a better solution to the problem, 15 years ago nearly every new car came with EGR and some still came with air pumps. Now, you would be hard pressed to find a single new car with EGR and I bet you couldnt find one with an air pump. As tech progresses, EGR should vanish from diesels as well. Or we can just accept that CBU is a fact of life and deal with constant failures and repairs as a result.
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      06-14-2014, 02:14 AM   #105
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Originally Posted by Hoooper View Post
the idea that NOx from passenger car diesels has any impact, whether lessened by EGR or not, on the environment is ludicrous. The 335d as rated in CA registered 0.00g/mi of NOx at highway speed. Now, thats probably something like 0.001 or something greater than actually 0, but the fact that you remove the EGR is not going to automatically put you into 1970 merc diesel territory. As stock the 335d is significantly less "polluting" on the highway than a prius. By deleting the EGR, you might instead put your d into the range of a 4 cyl Chevy Cruz
Accepting CBU as a fact of life is the same attitude that would have left us stuck with 175 HP 5.7L V8 cars getting 12 MPG instead of the 390HP 5.7L trucks getting 20 MPG that we have now. There is always a better solution to the problem, 15 years ago nearly every new car came with EGR and some still came with air pumps. Now, you would be hard pressed to find a single new car with EGR and I bet you couldnt find one with an air pump. As tech progresses, EGR should vanish from diesels as well. Or we can just accept that CBU is a fact of life and deal with constant failures and repairs as a result.
In your argument above you simply forgot the most important aspect: emissions regulation.
It has changed from virtually non existent to very restrict along the years. By the way, the state you live in is the responsibible for the extreme restriction on NOx limit levels. You should try to convince the government officials of your beliefs.
About comparing gasoline and diesel engines emissions: apples and oranges.
Fuel is different, burn, speed, engine cycle..... chemical reaction produces different results, the emission regulation is different...

When you burn fuel, you promote the oxidation of carbon, regardless of what fuel you are using. You also can't burn fuel without generating fumes, and partially oxidized carbon is part of these fumes. This will not change. It is a fact of life.
Also to accept is the fact that low cetane diesel, (lower flamability) delivers significantly more partially oxidized carbon after burn. Do not forget your 335d is designed to run on diesel with 51 cetane rating that is not widely found in US.
Furthermore, EGR is not the cause of CBU. It is on every high performance diesel and in contrary to your statement is coming back to gasoline engines. Funny that it is one of the responsible for engine efficiency improvement you refer.
Here is another fact of life: Eliminating EGR does not stop CBU.

We all need to be used to intake manifold maintenance. All direct injection engines do not have the fuel spray of old PFI technology to clean it. At certain point on engine life it will have to be done.

Among all tricks to manage the issue, the best is meth injection.
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      06-14-2014, 02:22 AM   #106
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Quote:
Originally Posted by Jffeijao View Post
.
Here is another fact of life: Eliminating EGR does not stop CBU.
[/quote]

As a broad statement this is probably true for things such as valves, but for the intake manifold and intake runners EGR is the primary source of CBU, otherwise, there is nowhere for partially oxidized carbon to come from but from the EGR. And as we are having a problem with the build up in the intake manifold and head runners, eliminating the EGR will solve the problem.
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      06-14-2014, 03:45 AM   #107
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Originally Posted by Yozh View Post

As a broad statement this is probably true for things such as valves, but for the intake manifold and intake runners EGR is the primary source of CBU, otherwise, there is nowhere for partially oxidized carbon to come from but from the EGR. And as we are having a problem with the build up in the intake manifold and head runners, eliminating the EGR will solve the problem.
I understand your rationale. You will definetely reduce the build up rate with EGR blocking. Intake maintenance interval would be greatly improved. CBU will be still on, but I agree: in negligible rate.
On the other hand you are trading off by:
-throwing out emissions much above the regulation limit.
-accepting some performance issues as the injection system software will compensate fuel delivery based on emissions closed loop.

I am on the oposite side of being a tree hugger so I do not care on emissions. I did not buy the D thinking about fuel consumption either. Just like playing the game within the rules.
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      06-14-2014, 03:46 AM   #108
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Originally Posted by Jffeijao View Post
This has been done. Many EGR recalls and an SIB on intake clean up have been released. Issue is caused by low fuel quality allied with very tight NOx emissions limits in US.

All the discussion about alternatives to stop CBU are measures to throw in the atmosphere the un treated diesel burn by products. They are all against the law.

The reality is: all direct injection engines require carbon build up removal as preventive maintenance. With the low grade US fuel some applications will require a smaller interval between clean ups.
your last statement is spot on, I don't mind CBU so much, it's a problem in all new cars with DI, it's when the CBU messes everything else up...
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      06-14-2014, 11:10 AM   #109
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Originally Posted by Jffeijao View Post
Furthermore, EGR is not the cause of CBU. It is on every high performance diesel and in contrary to your statement is coming back to gasoline engines. Funny that it is one of the responsible for engine efficiency improvement you refer.
What? I guess if you move the goalposts to a totally different version of CBU you *might* be right. But you're way off base with respect to CBU as we know it here.

EGR is not an efficiency benefit or improvement. That's actually the whole reason it works. EGR lessens the volume of available oxygen in the cylinder, slowing down the burn and lowering chamber temperatures. Since NOx is only formed at high temperatures, lowering chamber temperatures drastically reduces NOx. Its not an efficiency improvement to load the combustion chamber up with noncombustible material.

I don't mind playing within the rules, but when it means a choice between slightly lower emissions and several thousand dollar repairs vs $10 in material, better mileage, better performance, and no repairs, the choice is incredibly clear.
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      06-14-2014, 02:00 PM   #110
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Quote:
Originally Posted by Hoooper View Post
What? I guess if you move the goalposts to a totally different version of CBU you *might* be right. But you're way off base with respect to CBU as we know it here.

EGR is not an efficiency benefit or improvement. That's actually the whole reason it works. EGR lessens the volume of available oxygen in the cylinder, slowing down the burn and lowering chamber temperatures. Since NOx is only formed at high temperatures, lowering chamber temperatures drastically reduces NOx. Its not an efficiency improvement to load the combustion chamber up with noncombustible material.

I don't mind playing within the rules, but when it means a choice between slightly lower emissions and several thousand dollar repairs vs $10 in material, better mileage, better performance, and no repairs, the choice is incredibly clear.
You are correct when you consider old technology EGR.
However with all actuators in the engine being controlled by software, EGR can improve the efficiency of combustion engines. Below is how:

1- Reduced throttling losses. The addition of inert exhaust gas into the intake system means that for a given power output, the throttle plate must be opened further, resulting in increased inlet manifold pressure and reduced throttling losses. (Gasoline engines only as diesels are not throttled)

2- Reduced heat rejection. Lowered peak combustion temperatures not only reduces NOx formation, it also reduces the loss of thermal energy to combustion chamber surfaces;

3- Reduced chemical dissociation. The lower peak temperatures result in more of the released energy remaining as sensible energy near TDC (Top Dead-Center), rather than being bound up (early in the expansion stroke) in the dissociation of combustion products. This effect is minor compared to the first two.

4- In a closed loop injection system, with EGR open, software is calibrated to inject less fuel in the cylinders

On diesel engines the improvement is smaller then on gas, but also occurs. .

I do not debate that blocking EGR reduces CBU. Therefore I do not judge as irrational your assessment on paying 10 bucks on a blocking plate instead of mantaining a clean intake via other measures. I just think the best economical decision would be buying a PFI gas car instead of a DI. Much cheaper engines and zero CBU!

If you have a solution for the emissions puzzle that eliminates EGR without negative collateral effects, start making money on it. All OEM's are desperate for a cheaper solution and removing parts will help
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