strange noise from engine bay

hsk1610 · 06-10-2015, 03:58 PM

I have a strange noise from what it seems to come from the alternator when the engine is completely off. My dealer is baffled and wants me to leave it at future date for the tech to drive and duplicate. Here is the video. Hope someone can chime in with a dignosis/ similiar experience.

Edit: replaced 'starter' with 'alternator'

E90Fleet · 06-10-2015, 04:09 PM

Thats the alternator.
Starter is at the back of the engine.

It has a control panel on the back that is used by efficient dynamics to control charging, alternator load ect ect. Probably a fault in there

hsk1610 · 06-10-2015, 04:23 PM

Thanks for the response. At the dealer now redoing the wheel alignment and fixing rattles/ warped dash/trim panels.

I do hear that similar sound when accelerating, albeit at a low volume but continous, muffled under the engine sound.

CalCarNut · 06-10-2015, 04:23 PM

Quote:

Originally Posted by E90Fleet

Thats the alternator.
Starter is at the back of the engine.

It has a control panel on the back that is used by efficient dynamics to control charging, alternator load ect ect. Probably a fault in there

I was like 'huh? I know I don't know squat about BMW (yet), but that sure looked like an alternator to me". Glad I'm not crazy

...

Fronzdan · 06-11-2015, 10:22 AM

WTF is that? Maybe your car is a Transformer or something. I hear a faint high pitched tone every once in a while when the car is off. What would be going on while the car is off?

hsk1610 · 07-02-2015, 07:45 AM

So my car has been at the dealer since Monday for this issue. They are stumped and escalated to BMW but they have not encountered this issue either. The SA called asking for more info. Recently, in Eco-Pro mode, I noticed that I am not gaining any of the Eco-Pro miles that I used to see so that might be a hint as well.

In the meantime, enjoying the '15 528Xi that the dealer has given me as a loaner.

RoundelM3 · 07-02-2015, 08:08 AM

While that is the alternator in the video, it's driven by a belt and doesn't have any parts that will move if the engine isn't running. Hard to say what would make that noise, although it sounds sort of metallic, but it could be a number of things. Hope they can figure it out!

timmahh · 07-02-2015, 03:24 PM

It sounds like an electrical buzzing but it also sounds like something high pressure in a metal line; sort of like when you're using an air compressor and letting the compressed air out, the tank has that metallic sound to it.

hsk1610 · 07-06-2015, 03:29 PM

well the dealer called back after a week and they think it's the compressor. BMW hotline says they have had owners complain of similar noise in the West Coast so they will do some more tests and replace the compressor. I assume they mean the turbo compressor and not the A/C.

greekcs · 07-06-2015, 09:03 PM

Check for a dot matrix printer. Happens all the time.

casualDIYer · 07-10-2015, 06:50 AM

It might be turbo related. As far as I know the only mechanical system running after ignition is off is the coolant system to cool the turbo

hsk1610 · 07-10-2015, 01:13 PM

Finally got the car back after 2 weeks. They replaced the AC compressor and fixed some vacuum lines which were leaking near the radiator. Hopefully this resolves the issue.

06-10-2015, 03:58 PM	#1
hsk1610 Lieutenant 108 Rep 524 Posts Drives: 2013 328i xDrive Join Date: Sep 2013 Location: Chicago, IL iTrader: (0)	I have a strange noise from what it seems to come from the alternator when the engine is completely off. My dealer is baffled and wants me to leave it at future date for the tech to drive and duplicate. Here is the video. Hope someone can chime in with a dignosis/ similiar experience. Edit: replaced 'starter' with 'alternator'
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06-10-2015, 04:09 PM	#2
E90Fleet Lieutenant General 1311 Rep 10,185 Posts Drives: BMW Join Date: Apr 2005 Location: South Africa iTrader: (0)	Thats the alternator. Starter is at the back of the engine. It has a control panel on the back that is used by efficient dynamics to control charging, alternator load ect ect. Probably a fault in there __________________ BMW if you are reading, I need a job, Please.
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06-10-2015, 04:23 PM	#3
hsk1610 Lieutenant 108 Rep 524 Posts Drives: 2013 328i xDrive Join Date: Sep 2013 Location: Chicago, IL iTrader: (0)	Thanks for the response. At the dealer now redoing the wheel alignment and fixing rattles/ warped dash/trim panels. I do hear that similar sound when accelerating, albeit at a low volume but continous, muffled under the engine sound.
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06-11-2015, 10:22 AM	#5
Fronzdan Lieutenant Colonel 298 Rep 1,735 Posts Drives: '24 M240 xDrive Join Date: Mar 2014 Location: MA iTrader: (0)	WTF is that? Maybe your car is a Transformer or something. I hear a faint high pitched tone every once in a while when the car is off. What would be going on while the car is off?
	Appreciate 0 Quote

07-02-2015, 07:45 AM	#6
hsk1610 Lieutenant 108 Rep 524 Posts Drives: 2013 328i xDrive Join Date: Sep 2013 Location: Chicago, IL iTrader: (0)	So my car has been at the dealer since Monday for this issue. They are stumped and escalated to BMW but they have not encountered this issue either. The SA called asking for more info. Recently, in Eco-Pro mode, I noticed that I am not gaining any of the Eco-Pro miles that I used to see so that might be a hint as well. In the meantime, enjoying the '15 528Xi that the dealer has given me as a loaner.
	Appreciate 0 Quote

07-02-2015, 08:08 AM	#7
RoundelM3 Major General 1833 Rep 6,987 Posts Drives: 15 F80 M3, 22 G01 X3 30i Join Date: Apr 2010 Location: Wendell, NC iTrader: (2) Garage List 2022 BMW X3 [9.83] 2015 BMW M3 [6.50]	While that is the alternator in the video, it's driven by a belt and doesn't have any parts that will move if the engine isn't running. Hard to say what would make that noise, although it sounds sort of metallic, but it could be a number of things. Hope they can figure it out! __________________ 2015 F80 ///M3 Sedan 7DCT Tanzanite, 2022 X3 sDrive30i 8AT Brooklyn Grey
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07-02-2015, 03:24 PM	#8
timmahh ghey 483 Rep 2,041 Posts Drives: Viertürigen Fahrzeugs Join Date: Oct 2010 Location: Southern California iTrader: (1)	It sounds like an electrical buzzing but it also sounds like something high pressure in a metal line; sort of like when you're using an air compressor and letting the compressed air out, the tank has that metallic sound to it. __________________ 21 G05 > 20 G05 > 17 G30 > 14 F30 > 08 E90
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07-06-2015, 03:29 PM	#9
hsk1610 Lieutenant 108 Rep 524 Posts Drives: 2013 328i xDrive Join Date: Sep 2013 Location: Chicago, IL iTrader: (0)	well the dealer called back after a week and they think it's the compressor. BMW hotline says they have had owners complain of similar noise in the West Coast so they will do some more tests and replace the compressor. I assume they mean the turbo compressor and not the A/C.
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07-06-2015, 09:03 PM	#10
greekcs Major 773 Rep 1,113 Posts Drives: 2020 M340i xDrive Join Date: Jan 2010 Location: Long Island, NY iTrader: (0)	Check for a dot matrix printer. Happens all the time. __________________ 2003 11/02 Steel Gray Metallic on Red M3 - SMGII - VF570 - SUPERSPRINT - KW - BBS - CSL ROOF SOLD 2015 09/14 Alpine White on Red 435i xDrive MPPK - Expensive black vinyl with special lettering. SOLD 2020 12/19 Mineral Gray Metallic on Black Vinyl interior M340i xDrive
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07-10-2015, 06:50 AM	#11
casualDIYer Major 436 Rep 1,366 Posts Drives: 340i xDrive M Sport Join Date: Nov 2008 Location: Toronto iTrader: (0)	It might be turbo related. As far as I know the only mechanical system running after ignition is off is the coolant system to cool the turbo
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07-10-2015, 01:13 PM	#12
hsk1610 Lieutenant 108 Rep 524 Posts Drives: 2013 328i xDrive Join Date: Sep 2013 Location: Chicago, IL iTrader: (0)	Finally got the car back after 2 weeks. They replaced the AC compressor and fixed some vacuum lines which were leaking near the radiator. Hopefully this resolves the issue.
	Appreciate 0 Quote