F30 340i noise under hood

Willson1010 · 03-04-2021, 11:13 AM

Hey guys just looking for some input. I have a noise coming from under the hood(sounds like it's toward the back of the engine). It sounds almost like a fan(or something similar) coming on, running for a few seconds, then clunking quick when it stops. It does not have consistent intervals. Someone from the repair shop said it seems to be happening when there is a rush of air coming in from the intake? I can only hear it while idling. Not sure if that's because it only happens while idling or if the engine is too loud for me to hear it while driving. Also I have no check engine lights, car drives good and pulls hard just like it always has. If anyone has any ideas I would greatly appreciate advice!

cfm56d7b · 03-04-2021, 11:43 AM

Did you or your mechanic examine any stored fault codes?

Willson1010 · 03-04-2021, 11:45 AM

No he didn't he just listened quick as I was on my way out. Also I have bootmod3 stage 1 flashed on my car. Would that make the CEL not come on?

jmack · 03-04-2021, 12:46 PM

Quote:

Originally Posted by Willson1010

No he didn't he just listened quick as I was on my way out. Also I have bootmod3 stage 1 flashed on my car. Would that make the CEL not come on?

BM3 only suppresses the CEL related to catless downpipe, any other source will still come through.

Willson1010 · 03-04-2021, 01:14 PM

Well that's certainly good to know. Thanks

jackstrath · 03-04-2021, 03:21 PM

Been a few 2016 guys reporting Eccentric shaft going out on them recently....

https://f30.bimmerpost.com/forums/sh....php?t=1791007

03-04-2021, 11:13 AM	#1
Willson1010 New Member 3 Rep 14 Posts Drives: 2016 340i xdrive Join Date: May 2020 Location: Troy NY iTrader: (0)	F30 340i noise under hood Hey guys just looking for some input. I have a noise coming from under the hood(sounds like it's toward the back of the engine). It sounds almost like a fan(or something similar) coming on, running for a few seconds, then clunking quick when it stops. It does not have consistent intervals. Someone from the repair shop said it seems to be happening when there is a rush of air coming in from the intake? I can only hear it while idling. Not sure if that's because it only happens while idling or if the engine is too loud for me to hear it while driving. Also I have no check engine lights, car drives good and pulls hard just like it always has. If anyone has any ideas I would greatly appreciate advice!
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03-04-2021, 11:43 AM	#2
cfm56d7b Lieutenant General 5886 Rep 10,256 Posts Drives: 2017 440i Gran Coupe & 2015 X5 Join Date: Nov 2012 Location: Orange County, CA iTrader: (2)	Did you or your mechanic examine any stored fault codes?
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03-04-2021, 11:45 AM	#3
Willson1010 New Member 3 Rep 14 Posts Drives: 2016 340i xdrive Join Date: May 2020 Location: Troy NY iTrader: (0)	No he didn't he just listened quick as I was on my way out. Also I have bootmod3 stage 1 flashed on my car. Would that make the CEL not come on?
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03-04-2021, 01:14 PM	#5
Willson1010 New Member 3 Rep 14 Posts Drives: 2016 340i xdrive Join Date: May 2020 Location: Troy NY iTrader: (0)	Well that's certainly good to know. Thanks
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03-04-2021, 03:21 PM	#6
jackstrath Major 659 Rep 1,239 Posts Drives: 16' F31 340i & 03' Focus RS Join Date: Aug 2014 Location: Aberdeen iTrader: (0)	Been a few 2016 guys reporting Eccentric shaft going out on them recently.... https://f30.bimmerpost.com/forums/sh....php?t=1791007
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