F32 N55 strange noise on cold start

bimmer billy · 07-30-2020, 11:03 AM

Got about 90,000 miles on my 2014 435xi and the past couple days I started hearing a weird come from what sounds like the under carriage of my car on a cold start and while drive the first few yards. I don't how to describe the noise its like rattling/creaking noise. Anyone have any idea what it is?

Here is a YouTube video link

exE36M3 · 07-30-2020, 11:08 AM

At what point in the video do you hear the noise? I just hear what sounds like exhaust pulses stuttering.

bimmer billy · 07-30-2020, 12:31 PM

The noise is throughout almost the whole video, I posted another video which may be easier to hear the noise I am talking about.

thejeremyman9 · 07-30-2020, 01:10 PM

First, confirm its not the exhaust flap. Doesnt sound like it, but easy to check.

Does it only happen on cold starts?

It sounds like its a vibration rattle. Not clear if its RPM dependent since you didnt rev the car at all. I would get the car in the air, let it sit overnight (or long enough to be cold), then have someone cold start it while you are underneath.

07-30-2020, 11:03 AM	#1
bimmer billy Private First Class 17 Rep 176 Posts Drives: Sedona Red BMW 135 Join Date: Jul 2008 Location: Cranford, NJ iTrader: (0)	F32 N55 strange noise on cold start Got about 90,000 miles on my 2014 435xi and the past couple days I started hearing a weird come from what sounds like the under carriage of my car on a cold start and while drive the first few yards. I don't how to describe the noise its like rattling/creaking noise. Anyone have any idea what it is? Here is a YouTube video link __________________ 2008 Sedona Red 135i, JB3, Injen intake, 35% tint, Performance Rims, Performance Bumper, Performance Side Skirts, Boston Leather, Glacier Aluminum, iPod/USB, Sports Package w/ shifters, Premium Package, Heated Seats, Xenon's. Last edited by bimmer billy; 07-30-2020 at 12:12 PM..
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07-30-2020, 11:08 AM	#2
exE36M3 BMW CCA Member 488 Rep 808 Posts Drives: 2015 435i M Sport Join Date: Jan 2018 Location: NorCal iTrader: (4)	At what point in the video do you hear the noise? I just hear what sounds like exhaust pulses stuttering.
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07-30-2020, 12:31 PM	#3
bimmer billy Private First Class 17 Rep 176 Posts Drives: Sedona Red BMW 135 Join Date: Jul 2008 Location: Cranford, NJ iTrader: (0)	The noise is throughout almost the whole video, I posted another video which may be easier to hear the noise I am talking about. __________________ 2008 Sedona Red 135i, JB3, Injen intake, 35% tint, Performance Rims, Performance Bumper, Performance Side Skirts, Boston Leather, Glacier Aluminum, iPod/USB, Sports Package w/ shifters, Premium Package, Heated Seats, Xenon's.
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07-30-2020, 01:10 PM	#4
thejeremyman9 Major General 4364 Rep 7,607 Posts Drives: 2015 BMW 335i Join Date: May 2019 Location: Cali iTrader: (0)	First, confirm its not the exhaust flap. Doesnt sound like it, but easy to check. Does it only happen on cold starts? It sounds like its a vibration rattle. Not clear if its RPM dependent since you didnt rev the car at all. I would get the car in the air, let it sit overnight (or long enough to be cold), then have someone cold start it while you are underneath.
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