High pitched beeping noise coming from rear of car

magungo · 05-29-2015, 04:00 PM

Hi all,

I started my car this morning and noticed there was a high pitched beeping noise coming from the rear of the car. The car was just sitting idling while I tried to look for the source of it. The sound went away on it's own after about 2 minutes.

Has anyone else had this yet?

I'm thinking it might be related to the urea tank somehow. I'll connect to the ODB later and see if I can pull anything.

Added video that captures what it sounds like. I recorded this when I went to my car after work.

BB_cuda · 05-29-2015, 04:15 PM

Before my SCR was deactivated, I always heard a squeeling noise from back there just after engine shutoff. Of course squeeling and beeping are two different noises too. No beeping ever observed here.

Yozh · 05-30-2015, 10:18 PM

That video definitely helps. It does sound like an SCR tank related activity. Has the car ever been in a rear-end accident? If you are still under warranty I would take it in.

magungo · 06-01-2015, 04:14 AM

No, the car has never been rear ended. It only started happening recently. I'm no longer under warranty but I'm crossing my fingers that the 7 year CA warranty extension applies.

Mik325tds · 06-01-2015, 07:41 AM

Are you able to clear faults? If you are, try pulling fuse F05 (10A) which is located in the white box where the DDE sits. That will deactivate all pumps from the SCR. If the noise goes away after that we'll know for sure it has to do with the SCR system. If it doesn't - get that poor bird out of your exhaust!

magungo · 06-04-2015, 03:56 PM

Ok. I'll try to find out some documentation on how to access that this weekend.

I also have an appointment with BMW. They said it might be something involving the exhaust system but they won't know if it's covered by the emissions warranty until they check it out. 150 for diagnosis. I'm pretty sure the only thing back there is the exhaust. Would the fuel pump make noise like that?

Hoooper · 06-04-2015, 04:25 PM

DEF transfer pump could make that noise if its in rough shape. My car makes a noise from that area at the same rate while running. Hasnt changed pitch or rate ever from what I can tell so I just ignore it, but it doesnt sound like a dying bearing which yours kind of does.

05-29-2015, 04:00 PM	#1
magungo Private First Class 11 Rep 153 Posts Drives: Honda Civic Join Date: Aug 2009 Location: Bellevue iTrader: (4)	High pitched beeping noise coming from rear of car Hi all, I started my car this morning and noticed there was a high pitched beeping noise coming from the rear of the car. The car was just sitting idling while I tried to look for the source of it. The sound went away on it's own after about 2 minutes. Has anyone else had this yet? I'm thinking it might be related to the urea tank somehow. I'll connect to the ODB later and see if I can pull anything. Added video that captures what it sounds like. I recorded this when I went to my car after work. Last edited by magungo; 05-30-2015 at 01:19 AM.. Reason: Adding Video
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05-29-2015, 04:15 PM	#2
BB_cuda Brigadier General 765 Rep 3,557 Posts Drives: 2011 335D Msport, 2013 X5D Join Date: Nov 2011 Location: Clear Lake, Texas iTrader: (0)	Before my SCR was deactivated, I always heard a squeeling noise from back there just after engine shutoff. Of course squeeling and beeping are two different noises too. No beeping ever observed here.
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05-30-2015, 10:18 PM	#3
Yozh Colonel 870 Rep 2,615 Posts Drives: 2011 335d M-Sport Join Date: Mar 2014 Location: Wet Coast iTrader: (4)	That video definitely helps. It does sound like an SCR tank related activity. Has the car ever been in a rear-end accident? If you are still under warranty I would take it in.
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06-01-2015, 04:14 AM	#4
magungo Private First Class 11 Rep 153 Posts Drives: Honda Civic Join Date: Aug 2009 Location: Bellevue iTrader: (4)	No, the car has never been rear ended. It only started happening recently. I'm no longer under warranty but I'm crossing my fingers that the 7 year CA warranty extension applies.
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06-01-2015, 07:41 AM	#5
Mik325tds Major 807 Rep 1,191 Posts Drives: 335d M-Sport Join Date: Jul 2014 Location: Greater Detroit iTrader: (0)	Are you able to clear faults? If you are, try pulling fuse F05 (10A) which is located in the white box where the DDE sits. That will deactivate all pumps from the SCR. If the noise goes away after that we'll know for sure it has to do with the SCR system. If it doesn't - get that poor bird out of your exhaust!
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06-04-2015, 03:56 PM	#6
magungo Private First Class 11 Rep 153 Posts Drives: Honda Civic Join Date: Aug 2009 Location: Bellevue iTrader: (4)	Ok. I'll try to find out some documentation on how to access that this weekend. I also have an appointment with BMW. They said it might be something involving the exhaust system but they won't know if it's covered by the emissions warranty until they check it out. 150 for diagnosis. I'm pretty sure the only thing back there is the exhaust. Would the fuel pump make noise like that?
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06-04-2015, 04:25 PM	#7
Hoooper Colonel 213 Rep 2,210 Posts Drives: 335D Join Date: Jun 2013 Location: Petaluma, CA iTrader: (0)	DEF transfer pump could make that noise if its in rough shape. My car makes a noise from that area at the same rate while running. Hasnt changed pitch or rate ever from what I can tell so I just ignore it, but it doesnt sound like a dying bearing which yours kind of does.
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