# 328xd check engine light, again



## Seppo (May 12, 2014)

Several months ago had a check engine light and had to take it to the dealer. Turned out to be an exhaust sensor that had worked its way loose. Replacement sensor fixed the issue.

This morning CEL appeared again, thirty miles into the drive in 10 degree F temperatures. Suppose it might be a problem with DEF line freezing up in these temperatures, but we had several much colder days with no problems. Dealer can't see it until next week.

That's two CELs in only 18,000 miles, I did not have a single CEL in my Audi over 125k miles, the old 328i in 45k miles, and over 215k miles on my TDIs. Beginning to get nervous about BMW reliability, especially after having had such good experiences with Audi and VW.

We'll see what the shop says when they get their hands on it.


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## Flying Ace (Jan 26, 2015)

run a OBD II scanner on it and pull codes...


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## floydarogers (Oct 11, 2010)

Seppo said:


> ...
> This morning CEL appeared again, thirty miles into the drive in 10 degree F temperatures. Suppose it might be a problem with DEF line freezing up in these temperatures, but we had several much colder days with no problems. Dealer can't see it until next week.
> 
> That's two CELs in only 18,000 miles, I did not have a single CEL in my Audi over 125k miles, the old 328i in 45k miles, and over 215k miles on my TDIs. Beginning to get nervous about BMW reliability, especially after having had such good experiences with Audi and VW


You also didn't have a SCR system (DEF) on any of your VW cars.


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## ingenieur (Dec 26, 2006)

A few new TSB on the new diesels, but pretty sorted out now I hear.


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## Seppo (May 12, 2014)

The Passat had an Adblue system, but no problems in the short time I had it, less than 5k miles. Hope it isn't a weak link, reliability-wise


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## glangford (Dec 11, 2013)

ingenieur said:


> A few new TSB on the new diesels, but pretty sorted out now I hear.


I looked up the 328d on a website and didn't see any listed. What are the TSBs?


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## Hangman4358 (Nov 26, 2013)

glangford said:


> I looked up the 328d on a website and didn't see any listed. What are the TSBs?


Yeah, dropped of the wagon for its first service. SA said no recalls or bulletins out for the car.


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## Seppo (May 12, 2014)

Turned out about like I expected. It threw a lot of codes having to do with restricted flow in the diesel exhaust fluid delivery system. Known issues for low ambient temperature operation in the BMW service database, apparently, because there was some re-programming code readily available to clear one of the codes, and the CEL is cleared by the work done. I suspect very cold temperatures will cause problems with DEF systems for this car, I have heard of occasional issues with VW TDIs and a couple of Jeeps as well.

I had 1,500 miles remaining on the service indicator, so they did the 20,000mile service a little early since they had the car in the shop. I asked them to keep track of how much AdBlue was added, they put in two gallons since the last top-up 8,500 miles ago. That was in early October, so the colder winter temperatures probably result in higher AdBlue consumption.

Since the cold weather kicked in my measured MPG has dropped from 44-46mpg range to 40-41mpg range lately, one tank as low as 38mpg. That's a much bigger drop than I ever had with my TDIs, but they were not hampered by being tied to an automatic transmission. Maybe the run-flat Nokians hurt fuel economy, too, the non-runflat Nokians on my Audi and VWs actually improved mpg slightly compared to the all-season tires.

The loaner this time was an X1 2.8 sportline, much better seats than my no-line 328xd, and nice, tight steering like a Volkswagen or the BMWs of old, this 328xd steers more like an Audi A4quattro, just a bit too vague.

Anyhow, I hope the check engine light does not occur again. So far the DEF system seems to be the weak point in drivetrain reliability for these BMWs.


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## Seppo (May 12, 2014)

Well, that was fun. Picked up the car after the service and did not get half a mile away before the check engine light came on again. Took it back and they kept it another two days. Codes indicated problems in the DEF metering line, so they ordered replacement assembly and installed it. They test drove a while without the light reappearing, so I hope it is fixed once and for all. There is more cold weather forecast the rest of February, so we shall see if they have a fix that holds. I will be very disappointed if the emissions system cannot tolerate normal winter cold weather.


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## bayarea2007 (May 20, 2010)

Don't worry about the check engine light on BMW. They just set threshold too low. My approach is if the car runs fine, just leave it. Whenever I take my 335d to higher elevation, say a few thousand feet, the SES comes on. The car runs just fine, whether the SES is on or off.


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## need4speed (May 26, 2006)

bayarea2007 said:


> Don't worry about the check engine light on BMW. They just set threshold too low. My approach is if the car runs fine, just leave it. Whenever I take my 335d to higher elevation, say a few thousand feet, the SES comes on. The car runs just fine, whether the SES is on or off.


Surprising, unless you are talking many thousands of feet. We go up about 4000+ and don't have an issue. Maybe it's the fuel used? N4S


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## bayarea2007 (May 20, 2010)

Not sure why. Whenever I go to Lake Tahoe or Yosemite, I get SES. That's how I drew the link between them. After I return to sea level, the SES disappears after several days. If not, I just reset it and it never returns until I go up again


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## FredoinSF (Nov 29, 2009)

I've done the SF to Tahoe trek several times a month for many years and no CEL yet. If you're able to reset it yourself and CEL is fine around SF then no biggie, but what you're experiencing is not normal - even for pesky BMWs.


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## Seppo (May 12, 2014)

Prior to the CEL and the prolonged service, Eco Pro was not registering much benefit when I used it, I attributed it to not liking the cold winter temperatures. Previously if I used Eco Pro for about half of a forty-mile commute, over a tankful it might add up to 6 or 7 miles on the benefit indicator. Lately it would only give about 3 miles on a tankful, less most tanks because I wasn't using Eco Pro much in the colder temperatures of 25 degrees F and below.

Since the exhaust fluid metering line was replaced and software updated, I tried Eco-Pro for the first time, in 28 degree morning. In the first seven miles of driving the indicator added up, one-tenth of a mile at a time, to 5.0 miles benefits. That's just crazy, and leads me to conclude that BMW's fancy-schmancy electronics doo-dads are just as hinky and unreliable as ever, and not to be trusted. Kind of like the absurd trip computer on my old E36, it was an unreliable joke. At least these features don't critical functions, just not reassuring that maybe the critical electronic controls may be as buggy as the more frivolous ones.


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## DozerDan (Dec 18, 2013)

bayarea2007 said:


> Don't worry about the check engine light on BMW. They just set threshold too low. My approach is if the car runs fine, just leave it. Whenever I take my 335d to higher elevation, say a few thousand feet, the SES comes on. The car runs just fine, whether the SES is on or off.


Mine has been on since July, tells me my injectors are bad, problem is it cant keep track of which ones it wants to tell me at any given point in time. Ha Car runs fine. I scan it every now and then to make sure nothing new has popped up.


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## glangford (Dec 11, 2013)

My check engine light came on this morning. It was cold 8 degrees, even in a gulf coast state! At a light I used the request service option in the i-drive menu and it collected the data and sent it to the dealer. That was this morning about 6 am. It's 10:15 and the dealer has yet to call me. How long does it take them to respond to an i-drive service request?


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## ingenieur (Dec 26, 2006)

glangford said:


> My check engine light came on this morning. It was cold 8 degrees, even in a gulf coast state! At a light I used the request service option in the i-drive menu and it collected the data and sent it to the dealer. That was this morning about 6 am. It's 10:15 and the dealer has yet to call me. How long does it take them to respond to an i-drive service request?


That depends on the dealer - if the car is running fine I wouldn't worry, but call to set up an appointment.


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## glangford (Dec 11, 2013)

ingenieur said:


> That depends on the dealer - if the car is running fine I wouldn't worry, but call to set up an appointment.


I called them later that morning. I was hoping the car sent the error code messages. The SA said no, just what info is on the key relative to CBC. Seems odd, it wouldn't send error codes too. I may stop and have it read later today.


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