THE LARGEST BMW 2-SERIES FORUM ON THE PLANET
2Addicts
2Addicts
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
2Addicts | BMW 2-Series forum BMW 2 Series (F22) Forum BMW 2 Series Coupe and Cabriolet (F22/F23) General Forum 2014 M235i - Weird exhaust rattle for 10-20 seconds on cold start?

Post Reply
 
Thread Tools Search this Thread
      11-26-2019, 03:45 PM   #1
Vancity128guy
New Member
1
Rep
22
Posts

Drives: 2011 128i
Join Date: May 2017
Location: Vancouver

iTrader: (0)

2014 M235i - Weird exhaust rattle for 10-20 seconds on cold start?

Hi all,

I have a 2014 M235i with 55K KM's on the clock and it's been great thus far. I bought it pre-owned a few months ago. Unfortunately, there isn't any warranty left which is why I am asking here... Additionally, about two months ago I was rear ended by an idiot at a red light, relatively slow speed, but required the bumper, reinforcement bar to be replaced. Not sure if this issue is related to that...

The last two days it's been quite cold here, and I noticed after letting the car sit overnight, when I start it in the morning, there is a fairly loud rattle coming from the driver side exhaust area. It's pronounced when the RPMs get above 1000 on the cold start. After that, the sound goes away quickly (within 20 seconds) and it sounds normal again.

It's quite embarrassing sound to say the least. I have read about the exhaust flap/valve being an issue, but everything I read says that the sound would be constant if this was the issue.

Does anyone have any ideas what this could be?

Last edited by Vancity128guy; 11-26-2019 at 03:55 PM..
Appreciate 0
      11-26-2019, 04:12 PM   #2
RyonC
Private First Class
Canada
15
Rep
106
Posts

Drives: M235i
Join Date: Nov 2018
Location: Van

iTrader: (0)

You could try unplugging the valve and see if that fixes it.
Appreciate 0
      11-27-2019, 03:31 PM   #3
Vancity128guy
New Member
1
Rep
22
Posts

Drives: 2011 128i
Join Date: May 2017
Location: Vancouver

iTrader: (0)

Quote:
Originally Posted by RyonC View Post
You could try unplugging the valve and see if that fixes it.
OK might give this a try.

Anyone else experience this issue?
Appreciate 0
      11-27-2019, 04:35 PM   #4
BEM-S4
Major General
BEM-S4's Avatar
United_States
3775
Rep
8,197
Posts

Drives: Dinan M235, Dinan Sport Wagon
Join Date: Oct 2012
Location: Philadelphia

iTrader: (3)

Valve is likely bad and needs to be replaced. 5 minute job. They didn't even roll mine into the shop did it right in the intake bay.
__________________
2016 F23 M235 xDrive Convertible • Dinan Stage 2 • AA IC • Apex EC-7 • MPE
2016 F31 328 xDrive Sport Wagon • Dinan Stage 1 • Vorsteiner V-FF 105 • BBK
2006 E46 330ci ZHP Convertible • Apex ARC-8
Appreciate 0
      11-28-2019, 01:54 PM   #5
XutvJet
Brigadier General
2418
Rep
3,248
Posts

Drives: 2016 M235 6MT
Join Date: Mar 2016
Location: Kansas City

iTrader: (-1)

Don't bother replacing the valve as there is no long term fix. It always comes back. A simply fix is shooting some silicone penetrating oil around the external portion of valve assembly and it's bearings. The rattle will disappear for a good while. Mine rattles on and off since about 6 months after I got the car new back in Feb 2016. A quick shot of penetrating oil will quit it for 6+ months.
__________________
Country over party
Appreciate 1
Poochie3094.00

      11-28-2019, 03:38 PM   #6
Ron Jeffries
Old Member. Old in general, actually.
293
Rep
760
Posts

Drives: 2018 M240i xDrive convertible
Join Date: Feb 2013
Location: Michigan

iTrader: (0)

You guys are so lucky to have a flap. The 2018 doesn't even get a flap.
Appreciate 0
      11-28-2019, 05:22 PM   #7
ljason8eg
New Member
0
Rep
6
Posts

Drives: 2014 M235i
Join Date: Mar 2019
Location: California

iTrader: (0)

Quote:
Originally Posted by XutvJet View Post
Don't bother replacing the valve as there is no long term fix. It always comes back. A simply fix is shooting some silicone penetrating oil around the external portion of valve assembly and it's bearings. The rattle will disappear for a good while. Mine rattles on and off since about 6 months after I got the car new back in Feb 2016. A quick shot of penetrating oil will quit it for 6+ months.
Hey thanks for this tip. I recently got the dreaded rattle but noticed the fixing bow was still in place and the valve operates normally and when the valve is open the rattle disappears.

I'll try the silicone penetrating oil.
Appreciate 0
      11-28-2019, 10:30 PM   #8
RyonC
Private First Class
Canada
15
Rep
106
Posts

Drives: M235i
Join Date: Nov 2018
Location: Van

iTrader: (0)

Quote:
Originally Posted by Ron Jeffries View Post
You guys are so lucky to have a flap. The 2018 doesn't even get a flap.
Not rly useful. Car isn't much quieter with it closed... Probably why they took it out
Appreciate 0
      11-29-2019, 01:38 PM   #9
Climate Changer
Private First Class
Climate Changer's Avatar
United_States
49
Rep
156
Posts

Drives: 2018 230i xdrive convertible
Join Date: Oct 2018
Location: New York

iTrader: (0)

Garage List
2018 230i xdrive co ...  [0.00]
2019 x3  [0.00]
My 2018 230i has the flap. It rattled so much and the fixing bow was replaced and still rattled.

My fix= Muffler delete no more rattle only pops and burbles.
Appreciate 0
      11-29-2019, 02:28 PM   #10
9t2hoo
Private
33
Rep
81
Posts

Drives: 2017 EBII M240i 6MT
Join Date: Mar 2008
Location: Washington, D.C.

iTrader: (0)

I switched to the Remus exhaust and no more rattle. I hope it’s more durable than the OEM flap.
Appreciate 0
      11-30-2019, 10:10 AM   #11
Ron Jeffries
Old Member. Old in general, actually.
293
Rep
760
Posts

Drives: 2018 M240i xDrive convertible
Join Date: Feb 2013
Location: Michigan

iTrader: (0)

I want the car noisier, not quieter. My 135IS had so much more snap, crackle, and pop. Took me back to my teenage years.
Appreciate 0
      11-30-2019, 10:18 AM   #12
Poochie
Luxury at the redline :)
Poochie's Avatar
United_States
3094
Rep
3,578
Posts

Drives: 2016 M2
Join Date: Aug 2012
Location: NYC

iTrader: (1)

Quote:
Originally Posted by XutvJet View Post
Don't bother replacing the valve as there is no long term fix. It always comes back. A simply fix is shooting some silicone penetrating oil around the external portion of valve assembly and it's bearings. The rattle will disappear for a good while. Mine rattles on and off since about 6 months after I got the car new back in Feb 2016. A quick shot of penetrating oil will quit it for 6+ months.
I thought about this bandaid fix but I figure the hot exhaust would just dissipate the lubricant.

Roughly, how long it takes before oil wears out and noise reappears?
Appreciate 0
      12-01-2019, 12:43 PM   #13
DaleHeinz
Second Lieutenant
DaleHeinz's Avatar
184
Rep
288
Posts

Drives: M240Xi Estoril Blue
Join Date: Apr 2017
Location: Washington DC area

iTrader: (1)

I've already had 2 valves replaced in my '17 240. The rattle is very annoying and gets worse over time. Both times the dealer covered the replacement, and didn't care that it was out of warranty for the second one. I get about 30K miles out of one before they go. Next one I may do myself if they don't cover it.
Appreciate 0
      12-03-2019, 01:20 PM   #14
B58togo
Captain
509
Rep
949
Posts

Drives: M240i
Join Date: Feb 2017
Location: NY

iTrader: (0)

Quote:
Originally Posted by 9t2hoo View Post
I switched to the Remus exhaust and no more rattle. I hope it’s more durable than the OEM flap.
I did this too. Awesome exhaust and not a bad price either. Relatively speaking of course.
__________________
2017 M240i AW/ ZF8/ Bootmod3 Stage 2 E30/ xHP Stage 3 trans/ ER catless DP/ Remus axle back/ BMS intake

11.8 @ 118 mph/11.9 @ 119 mph
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 02:12 PM.




2addicts
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST