BMW will recall diesel models to fix emissions glitch

Just getting back to 'compression ignition' basics. I thought with a diesel, as long as there is enough air, more fuel = more power. That's what got me thinking how could we be using more fuel but not getting any power out of it. What popped into my head was a late cycle injection of fuel, just as the extra fuel for DPF burnoff adds zero power.

Originally Posted by KeithS

Just getting back to 'compression ignition' basics. I thought with a diesel, as long as there is enough air, more fuel = more power. That's what got me thinking how could we be using more fuel but not getting any power out of it. What popped into my head was a late cycle injection of fuel, just as the extra fuel for DPF burnoff adds zero power.

I believe we are getting more power post reprogram; at least I "feel" like I am.

While we may have more peak power available, the discussion is about the amount of fuel it takes to make a certain amount of power. For example it takes a specific amount of power to go a constant 60 MPH on a level road. That should use a specific amount of fuel. We are saying (for some of us) it now takes more fuel to make the power needed to go 60 MPH.

While having more peak power available may be a plus to some, I'm more interested in the economy. If I wanted more power I would have purchased the less expensive 335i. Just my 2 cents.

Originally Posted by KeithS

While we may have more peak power available, the discussion is about the amount of fuel it takes to make a certain amount of power. For example it takes a specific amount of power to go a constant 60 MPH on a level road. That should use a specific amount of fuel. We are saying (for some of us) it now takes more fuel to make the power needed to go 60 MPH.

While having more peak power available may be a plus to some, I'm more interested in the economy. If I wanted more power I would have purchased the less expensive 335i. Just my 2 cents.

I hear what you are saying as it relates to power and efficiency. I can only surmize that the reprogram influenced the fueling map in 6th gear in such a way that perhaps power is down at the lower rpm range, which would otherwise result in an increase in fueling in generate the same amount of power at that particular rpm to keep the car moving at a constant speed. If there is any truth to that then the new mapping could be tied to throttle position and or gearing. Perhaps an unintended consequence.

I would very much like to see a hp/torque curve post recall flash and compare it against a pre_recall dyno. Perhaps TDIWYse can do some logging and compare pre/post fueling logs?

Originally Posted by cssnms

I would very much like to see a hp/torque curve post recall flash and compare it against a pre_recall dyno. Perhaps TDIWYse can do some logging and compare pre/post fueling logs?

Unfortunately there are some "things" that eliminate that possibility . . . However, I can do some logs looking at the post injection events/DPF temps under light loads and compare to some limited data I have pre recal. Will see if I can do that before I leave on vacation in a few days.

http://www.bimmerfest.com/forums/sho...83#post7044083

Post #67 has some interesting data regarding differences in pre-post recal EGR and exhaust gas temp behavior for my drive to work, which is ~15 miles mostly county roads at 60mph with the last few miles city traffic.

A note on the data. Pre-recall is from March of this year on a morning in the mid 40 F range. Today's data is on a morning in the mid 60's F.

EGR duty cycle is significantly increased in an attempt, apparently, to slightly increase the average DPF temps. More EGR utilization would reduce NOx with less urea. I'd rather add urea and have less EGR.

Originally Posted by TDIwyse

EGR duty cycle is significantly increased in an attempt, apparently, to slightly increase the average DPF temps. More EGR utilization would reduce NOx with less urea. I'd rather add urea and have less EGR.

Agreed. Now we just need to get you engineering types to work on an EGR by-pass like the one the Euro 335d's are installing.

Guys if you really want toi know what the long term reliability will like visit the owners that have been driving these cars for a few years longer than us under the UK subsection of e90 Post. I made a post inquiring about the types of problems UK owners encountered and to state how many miles were on their cars. I don't recall new transmissions being common theme. I will see if I can find that post. For the most part people seemed happy with their BMW diesels.

Here we go... Not all 335d's but interesting/informative nonetheless.

http://www.e90post.com/forums/showthread.php?t=609922

Yeah but they have different EGRs and different .......

Originally Posted by Snipe656

Yeah but they have different EGRs and different .......

Yes they have different EGR's and no DEF system... I thought it might shed some more light on the topic. From what I gathered most seemed happy and many have well over 100k miles on their cars.

Originally Posted by cssnms

Yes they have different EGR's and no DEF system... I thought it might shed some more light on the topic. From what I gathered most seemed happy and many have well over 100k miles on their cars.

I was just trying to beat someone else from stating differences. Of course a lot more than just what we said but I do agree with what you have gathered.

I did the recall in May. First I though I was getting lower mileage but after few tanks of diesel I can say the MPG is about the same as before. We had a vacation trip last month 90% highway. It showed average 29mpg. It had 590 miles on the odometer when the fuel reserve light came on. I think this is amazing for 5000lb 4wd SUV
The car is now due for an oil service so I called to setup an appointment. The guy said there is a second emission recall after the first one.
Later on I received confirmation e-mail where I can read:
Recall - B18 06 12 0018430100 , E70 E90 M57 SCR Mixer

Anyone knows what is this about and anyone had this done?

My d completed 2nd recall last month ( both recall invoices were listed under thread count #404):

Originally Posted by bayoucity

I drop off my vehicle a few days ago for DEF fill-up & my SA advises me about the new recall on 335d. I am pleasantly surprise that he is on top of campaign bulletin for oil burners.

I am enclosing both recall invoices below so that you can see for yourself what are being replaced.

#1. May 18th, 2012 - EGR Valve (Bulletin 11 04 12) ; &

#2. August 17th, 2012 - SCR Mixer (Bulletin 18 06 12)

Originally Posted by tol4o

I did the recall in May. The car is now due for an oil service so I called to setup an appointment. The guy said there is a second emission recall after the first one.
Later on I received confirmation e-mail where I can read:
Recall - B18 06 12 0018430100 , E70 E90 M57 SCR Mixer

Anyone knows what is this about and anyone had this done?

Just did a quick research
On the X5 the mixer to be replaced is 18308513445
http://realoem.com/bmw/showparts.do?...16&hg=18&fg=10

It may be a different number for the updated part, I'll report next week after the service is completed

Sticking this thread for now, seems to still have a lot of good information.

I just had the SCR Mixer recall done when I took my X5d in for its scheduled service. Now I seem to be getting 2mpg less. I noticed it right away and this was before I knew about this discussion. In fact, it was because I observed a decrease that I searched and found this thread. Now it is still too early to tell but I track my mileage and will be able to run a test for statistical significance, which I'll report back with, probably in a couple of months. But right now I am very concerned.

Thanks Chris

I think it has been enough time and fill ups since I had my car done. The fuel economy has not picked back up. I am consistently in the 27.x instead of the 29.x ranges that I normally am in these times of the year.

Damn egr!!!

Originally Posted by sirbikes

I just had the SCR Mixer recall done when I took my X5d in for its scheduled service. Now I seem to be getting 2mpg less. I noticed it right away and this was before I knew about this discussion. In fact, it was because I observed a decrease that I searched and found this thread. Now it is still too early to tell but I track my mileage and will be able to run a test for statistical significance, which I'll report back with, probably in a couple of months. But right now I am very concerned.

Can't see how the SCR mixer would have any impact on MPG, it's way downstream of the engine. Now if they updated the DME, that's a different story.

Frankly I believe its the NEW settings the gave us in or reflash, I have the RENNtech flash and when the EGR went for me, I lost part of my RENNtech flash I had clocked 300 whp and when I did the dyno I clocked soemwhat 265 whp, I lost 35 ponies, anyway if eel Im still getting the same amount og mpg as I did before 20-23 mpg city depending on my need for speed!!!

They did a reprogram on mine also.

If you want to check for statistical significance, have about 12 to 20 or more mpg readings (preferably hand-calculated at fill-ups) before and after. Then run a two sample t-test on the data to test if the two averages are significantly different. You can also check to see if the standard deviations have changed significantly by doing an F-test.

You can use Excel or Minitab. If you give me your data I can run the tests for you.

All of my fillups are "hand calculated", I track all of them in an application and have a running log since the day I bought the car. It definitely has gone down roughly 2mpg since the recall.

Mines is hand calculated also.