E90Post
 


TNT Racewerks
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > E92 335i N54 - Left exhaust valve opens when idling?



Reply
 
Thread Tools Search this Thread
      04-18-2012, 07:19 AM   #1
sylonien
Major
 
Drives: cardboard box
Join Date: Apr 2012
Location: recycling bin

Posts: 1,131
iTrader: (0)

E92 335i N54 - Left exhaust valve opens when idling?

Hello, new member here!
I recently noticed that when I start my car and it leave it to idle, the left valve in the exhaust opens by itself after a while? Thought it meant to do that only after a certain RPM when driving?

I recorded two video to show it here and the RPMs.


sylonien is offline   United Kingdom
0
Reply With Quote
      04-18-2012, 07:22 AM   #2
Lulz_M3
Banned
 
Drives: AW 335i 6MT
Join Date: Oct 2011
Location: Jax, Fl

Posts: 1,029
iTrader: (0)

There is alot of speculation but no one has definitive proof of when and what that valve is suppose to do. In my opinion, it is used to limit the noise produced on cold starts since the RPM's are higher and the wastegates are wide open = LOUD. Other theories are that it is used to warm the cats, its suppose to stay closed under certain RPM conditions etc, please add your opinion to the pile LOL.
Lulz_M3 is offline   United_States
0
Reply With Quote
      04-18-2012, 07:29 AM   #3
enrita
Major General
 
enrita's Avatar
 
Drives: 335i - Big turbos
Join Date: Sep 2008
Location: Italian in Sweden

Posts: 7,318
iTrader: (0)

normal. warm up the cats and limit sound when on light throttle.
__________________
07 335i AT - TD St.2 Turbos - COBB (Custom Cobb mapping by http://www.protuningfreaks.com/) - JB4G5 ISO - Okada Coils - NGK 5992 Plugs - E85 Walbro - Injen Intake - Helix IC - Snow Stg. 3 - Stett CP - AR DPs - midpipes 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - Level 10 AT upgrade - Alpina AT Flash
enrita is offline   Sweden
0
Reply With Quote
      04-18-2012, 07:29 AM   #4
sylonien
Major
 
Drives: cardboard box
Join Date: Apr 2012
Location: recycling bin

Posts: 1,131
iTrader: (0)

My theory is that it's suppose to make it louder when open and allow more waste gas to escape? :P

But if you watched my first video, what I don't get is that after a while on a cold start, the valve opens automatically even though it's stationary and is sort of quieter when the left side opens up, along with the RPM dropping down to 600rpm instead of the initial 1100~RPM.

I don't really mind either way, just curious why it does that automatically and where all the people do the "golf tee mod" or unplugging stuff when mine does it like that?
sylonien is offline   United Kingdom
0
Reply With Quote
      04-18-2012, 07:30 AM   #5
sylonien
Major
 
Drives: cardboard box
Join Date: Apr 2012
Location: recycling bin

Posts: 1,131
iTrader: (0)

Quote:
Originally Posted by enrita View Post
normal. warm up the cats and limit sound when on light throttle.
Limit sound by opening up? Does it close again when it's hot then?
sylonien is offline   United Kingdom
0
Reply With Quote
      04-18-2012, 07:31 AM   #6
enrita
Major General
 
enrita's Avatar
 
Drives: 335i - Big turbos
Join Date: Sep 2008
Location: Italian in Sweden

Posts: 7,318
iTrader: (0)

Quote:
Originally Posted by sylonien View Post
Limit sound by opening up? Does it close again when it's hot then?
limit sound by closing. All latest cars have this. just look in the pipes of another Audi or BMW in front of you when driving.
__________________
07 335i AT - TD St.2 Turbos - COBB (Custom Cobb mapping by http://www.protuningfreaks.com/) - JB4G5 ISO - Okada Coils - NGK 5992 Plugs - E85 Walbro - Injen Intake - Helix IC - Snow Stg. 3 - Stett CP - AR DPs - midpipes 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - Level 10 AT upgrade - Alpina AT Flash
enrita is offline   Sweden
0
Reply With Quote
      04-18-2012, 07:47 AM   #7
sylonien
Major
 
Drives: cardboard box
Join Date: Apr 2012
Location: recycling bin

Posts: 1,131
iTrader: (0)

Thought so, what I don't get is why does it open up when idling then and not even touching the throttle.
sylonien is offline   United Kingdom
0
Reply With Quote
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
Forum Jump


All times are GMT -5. The time now is 04:37 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
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