# Car records miles since last DPF regen and assessment of fuel quality



## autoJeff (Oct 1, 2009)

Had an interesting conversation with a BMW shop foreman recently. Among other things, we discussed exhaust soot and frequency of DPF regeneration.

First, I want to say that Performance BMW in Chapel Hill seems like a great place to have work done on your luxury oil burner. There's a shop foreman there that is very knowledgeable, seems genuinely interested in the diesels, and has on a couple occasions taken time to talk with me about the cars and answer all of my questions. I have high confidence in his ability to treat my car right.

He said that the car records an assessment of fuel quality. I think he said it's an indication of cetane rating. Told me that the car believes the quality of the fuel currently in my tank is good. FWIW, the current tank of fuel is mostly from a Shell in Chapel Hill mixed with left overs from the previous fillup at a BP in Morrisville. We do not have premium-labeled diesel in my region.

According to the ship's log my last DPF regen was a hundred something miles ago. I don't think he has data for when the next-to-last regen occurred. I'd like to see historical data indicating when each regen happened and correlate that against highway vs. city driving. I am curious if there's an affordable scanner on the market that one could periodically hook up to read and log this information.

I did notice this weekend that a fan continued to run for a while after parking the car in my garage. That happens from time to time even when a fan seems unnecessary. E.g., after puttering home about a mile from the grocery and its not even hot outside. Is that a common occurrence for others too? I've been wondering if it is related to DPF regen. In this case it might have been. He said that when the fan runs, if you lock the car then the fan will probably stop running about 3 minutes later as the car completes its shut down sequence.

Apparently some older cars might not gather (or export?) the data about cetane and DPF regens. My Jan 2009 build car's software was updated last fall to I think the software that shipped on the first 2010 MY cars.

I saw another 335d parked near mine. This is the first time in the USA that I've seen another BMW 'd' that wasn't for sale on a dealer lot. Although it was in a dealer parking lot so it only 1/2 counts. I'm a geek. I compared the inside of that one's exhaust pipes to mine, and then compared against a couple nearby 335i cars.


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## Kanuck (Feb 18, 2003)

autoJeff said:


> I compared the inside of that one's exhaust pipes to mine, and then compared against a couple nearby 335i cars.


What did you observe?


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## Chrisdridley (Jun 29, 2009)

My fan continues to run sometimes too......it seems to me that it is when the DPF is burning off.
Look out for me around your area....I travel through several times a week.


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## lalitkanteti (Nov 15, 2009)

Surprisingly when I got into my d in morning it felt like it just burnt DPF. Need to check manual if it burns out even when its shut down.

But many times no matter how cold or hot it is, fan starts running after a short ride. I always thought it to be in middle of DPF burning


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## Chrisdridley (Jun 29, 2009)

Chrisdridley said:


> My fan continues to run sometimes too......it seems to me that it is when the DPF is burning off.
> Look out for me around your area....I travel through several times a week.


DPF = Diesel Particulate Filter 
DEF = Diesel Exhaust Fluid


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## autoJeff (Oct 1, 2009)

My car is getting updated to the latest software. He hopes that newer software will unlock an ability to see more of the history related to DPF regens and/or fuel quality, which he'll check the next time the car is in for service. One of the issues I raised is that sometimes, after washing the car, I'll fairly quickly accumulate some dark particulates at the rear of the car. I've been wondering if it happens during regens. Same for the fan running after turning off the car. That of course raises the question of how often regens are actually occurring because I observe these things more frequently than regens are probably supposed to occur.



Chrisdridley said:


> My fan continues to run sometimes too......it seems to me that it is when the DPF is burning off.





lalitkanteti said:


> But many times no matter how cold or hot it is, fan starts running after a short ride. I always thought it to be in middle of DEF burning


Yes, that's what I'm talking about. The next time I have the car in for service the updated software will hopefully give more visibility into what's really going on.

Frequency of DPF regen depends on driving conditions. I think the mechanic said that a regen every 1000 to 2000 miles would be considered normal. Hmm, I should ask him again.

Chris, do you have a feel for how often your car's fan runs after turning it off? Since you drive crazy amounts of highway miles over city miles your results probably should be different than mine. When just driving around the RTP area I think I experience the fan a lot more often than every 1000 miles but I'm not sure. We'll see what the regen history says the next time I have the car in for service. While on a road trip I do not remember ever experiencing the fan continue to run after turning off the car, only when driving around the city.



lalitkanteti said:


> Surprisingly when I got into my d in morning it felt like it just burnt DEF.


Can you please elaborate on how you think you "feel" that the DPF is doing a regen? I've noticed that sometimes my fuel economy appears to be down a couple mpg vs. what I think is normal for a well-travelled route. I've never noticed a decrease in engine power. I do not expect to feel a regen-related small decrease in power during normal street driving.

The car says that the expected life of my DPF is another 144,804 miles. He mentioned something about, IIRC, sensors measuring pressure difference across the DPF as one of the ways that the car decides when its time to do a regen to burn off the accumulated particles. The car does tell you how long it's been since the previous regen. And the updated software might expose a history of when the last N regens occurred.

The mechanic said that he has a way to force a regen in the shop while connected to his equipment. But not something that we can do on the road by ourselves. E.g., if you knew you were about to track the car, you could bring it in and ask them to force a regen to ensure it does not regen while driving around the track. And to minimize exhaust back-pressure due to the DPF.

I asked if the car has an electric coolant pump that can cool the turbo after turning off the engine. He said belt-driven pump only. I asked how the residual heat function operates given no electric pump. Electric heater. I guess that settles a debate I've had with myself...is it better to use residual heat function to heat the cabin by stealing heat from the engine, or is it better to let the cabin cool and keep the engine as warm as possible to minimize wear and emissions when the engine is restarted a short time later. Since residual heat in this car is powered by the battery, not by actual engine heat, there is no such tradeoff. I'm not too concerned about possibly shortening the life of the battery.



Kanuck said:


> What did you observe?


Not surprisingly, the exhaust pipes on the 'd' are cleaner than on the 'i'. My pipes look similar to the other 'd'. The 'd' does not have the flap that directs exhaust to one pipe so the 'd' pipes are uniform in appearance. He said that when their detail crew cleans the exhaust pipes they use 0000- steel wool with a little window cleaner like windex.



Chrisdridley said:


> Look out for me around your area....I travel through several times a week.


Chris, I can recommend a few restaurants in the RTP area. Can even meet you at one for lunch sometime if you're looking for company.


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## gator_babito (Jun 25, 2010)

Hi, I am new to this forum and have a 2010 335d which I bought in Dec. 2009. I got this burning smell and fans purring away on the 3day after I got the car, I freaked out and took it to the dealership here in Gainesville. Fl. and the dealership guy told me that nothing is wrong with the car and tha **** just burning off some newbie stuff under the hood. I didn't believe him and thought that he was BSing me. The problem was I could never reproduce the problem when i took it to the dealership. My car has 5K miles now, but i noticed this "overheating" and fans purring away at least 4 times in the last 7 months since i bought it. All my driving is in town and not on the highway. Also, the avg. temps. here have been 95F+ lately. I also noticed that the car sometimes struggles to pick up bt not always. Other than this, there are no problems. My first reaction to this problem was, geez, what the hell did I pay for, i used to have an X5 for several yrs. before getting this one and wasn't happy with that at all. Hope what I am seeing is not a serious problem. I haven't taken my car for the first servicing yet and will do so when i get to the 1 yr. time point. I read the thread and thought you guys are way knowledgeable in car mechanics. Much appreciate any suggestions on what to do.

thanks


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## lalitkanteti (Nov 15, 2009)

congrats on your new ride

everything is normal. smell and fan
About not having good pick up does it happen any time or just in mornings. Its reasonable to have low pick up in morning coz engine is not heated up. But if it happens after a while of driving then fuel can be culprit. make sure you always get premium fuels like shell

burning thing is common. get used to it. You will smell it every now and then probably every few thousand miles and DPF is common in all new diesels. 

enjoy your ride


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## gator_babito (Jun 25, 2010)

No, it happened a couple of times late mornings by which time, the temps here in Florida are already in the 90s. It noticeable when i try to accelerate from a stop light. Its like the engine was groaning. But it didn't happen all the times. So, its not clear why it did. I am wondering if its got anything to do with the particulate burn off you guys were talking about. Obviously, i can not hear the fans purring when I am inside the car. Oh, I forgot to mention that i fill BP Diesel and not Shell simply because its closer, but it does say on the pump that its very high grade Diesel.

thanks


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## Snipe656 (Oct 22, 2009)

The last couple of times I drove my car, the fans were turning on immediately after starting the thing up. I thought that was strange but just went on with my driving. When I commute in the car I think I smell the burn off process at least once a week but I am putting upwards of 1k miles a week on whatever I am commuting in so figured that is normal.


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## ghughes20 (Feb 27, 2010)

My does this too from time to time. It seems like it's happening more often now that the weather is warmer. I've had other cars do this and never gave it much thought.



gator_babito said:


> Hi, I am new to this forum and have a 2010 335d which I bought in Dec. 2009. I got this burning smell and fans purring away on the 3day after I got the car, I freaked out and took it to the dealership here in Gainesville. Fl. and the dealership guy told me that nothing is wrong with the car and tha **** just burning off some newbie stuff under the hood. I didn't believe him and thought that he was BSing me. The problem was I could never reproduce the problem when i took it to the dealership. My car has 5K miles now, but i noticed this "overheating" and fans purring away at least 4 times in the last 7 months since i bought it. All my driving is in town and not on the highway. Also, the avg. temps. here have been 95F+ lately. I also noticed that the car sometimes struggles to pick up bt not always. Other than this, there are no problems. My first reaction to this problem was, geez, what the hell did I pay for, i used to have an X5 for several yrs. before getting this one and wasn't happy with that at all. Hope what I am seeing is not a serious problem. I haven't taken my car for the first servicing yet and will do so when i get to the 1 yr. time point. I read the thread and thought you guys are way knowledgeable in car mechanics. Much appreciate any suggestions on what to do.
> 
> thanks


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## TridentFrog (Apr 8, 2010)

Hey Gator_babito, 

I agree with the suggestion of sticking to name brand fuel vs cosco...etc. 

Also since you received your d with some miles on it, try reseting the adaptive transmission settings. I did that after the "break in" period and noticed a difference, and again after installing Terry's Diesel tuner. Which by the way is a panty dropper....


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## Snipe656 (Oct 22, 2009)

TridentFrog said:


> again after installing Terry's Diesel tuner. Which by the way is a panty dropper....


What setting do you have his tuner at? Have you run into any issues?


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## TridentFrog (Apr 8, 2010)

Snipe656, 
The default setting is 65% which is where I have it in, for now. Going to keep it there for a week or so and bump it up by 10%. No issues so far. Noticed my service interval dropped from 8000 to 7000 miles after 48hrs of use, but that might of been a coincidence. Have noticed that the MPG gauge lean more to the left than before. The car has more of a bite on take off. Passing at highway speeds is very impressive.

Stugots, 
I have not thrown any codes up to this point. When the car does need to go in for its scheduled service, does the BT cable need to be used to clear any signs of the JBD being installed? Is there a record of the mod made somewhere in the ECU? I messed with the software a bit and began to be confused when I didn't see any current model years on the choice screen. Figured i'd read more on it and ask around before I ran into trouble.


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## Snipe656 (Oct 22, 2009)

The basic cable on here, that is what is being referred to in some threads as the BT Scanner that will clear codes?

http://www.burgertuning.com/scanner.html

And is that the BT Cable mentioned in the first post on here?

http://www.n54tech.com/forums/showthread.php?t=5571


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## TridentFrog (Apr 8, 2010)

Snipe656, 

Those sites show/talk about the same cable.


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## Snipe656 (Oct 22, 2009)

Thanks, just trying to figure out what all is needed to have it and to be able to clear things. From the sounds of it what is offered on that beta link would be everything needed to do that.


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## gator_babito (Jun 25, 2010)

TridentFrog said:


> Hey Gator_babito,
> 
> I agree with the suggestion of sticking to name brand fuel vs cosco...etc.
> 
> Also since you received your d with some miles on it, try reseting the adaptive transmission settings. I did that after the "break in" period and noticed a difference, and again after installing Terry's Diesel tuner. Which by the way is a panty dropper....


I received the car brand new and it didn't have any miles on it. Since my last posting, the car fans came on 2 times already. They seem to come on more frequently. maybe its because all my driving is city driving and no highway driving at all. I drive about 30 miles in city every day.
I know its more fun to take this on the highway but I am not that lucky with extra time.

Is this adaptive transmission setting you are referring to, in the on board computer under the system link? what does it do?

Thanks.

gb


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## ProRail (May 31, 2006)

TridentFrog said:


> Hey Gator_babito,
> 
> I agree with the suggestion of sticking to name brand fuel vs cosco...etc.
> 
> Also since you received your d with some miles on it, try reseting the adaptive transmission settings. I did that after the "break in" period and noticed a difference, and again after installing Terry's Diesel tuner. Which by the way is a panty dropper....


Costco fuel should not be a problem. If it seems to be, contact Costco. They are very responsive to members' complaints. Costco members are very demanding consumers, and Costco management is aware of that.


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## Snipe656 (Oct 22, 2009)

Since I doubt Cosco has refineries, it leaves me to question where the fuel comes from and what(if any) additives are put in. My guess is it is nothing special like most places like that which sell fuel. I'd ask them but do not even have them as an option for fuel down around here.


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