Exhaust flap rattle fix?

egregor · 08-02-2012, 11:34 AM

After about 20 seconds from starting the car, my exhaust makes the "coin clanging around a a coffee can" sound, and my exhaust becomes a bit louder. If i'm understanding these forum posts correctly, this is due to a loose/malfunctioning exhaust flap in the driver's side pipe, correct?

If so, there have been 3 approaches I've seen to deal with it: Golf tee/zip tie the vacuum line, unplug the unit from the trunk, or replace the pipe/go aftermarket. Is there really no official fix for this so I can not run the risk of throwing codes, failing emissions, losing HP, or facing any other unintended consequences that BMW so clearly tried to avoid by putting this assembly there in the first place? Obviously these pipes didn't come from the factory like this, isn't there a DIY or something for just.. fixing the problem, or is that not possible?

longliven54 · 08-02-2012, 05:28 PM

Do The golf tee mod, and forget about the rest. You are over-thinking about the possible consequences and codes and what not

egregor · 08-04-2012, 01:19 PM

*shrug* fair enough. Golf tee it is!

Zebra99 · 08-04-2012, 05:48 PM

If you have a JB4 you can have canflap open at all times.

If you are concerned with the clanking it's just the car getting warm. Once it's warm flap opens and noise should go away.

If you have the noise at all times than yes golf-t if the above doesn't apply to you.

Just make sure it's not your WG lol, cuz those things rattle like bi*ches on almost every 335!

boostaholic786 · 08-04-2012, 07:08 PM

You need to enable the CAN flap on the JB4 to where it stays open all the time. I personally dont like unplugging plugs that do more than just control the exhaust valve. As far as I know. I remember somebody saying something about that it has more features than just opening and closing the exhaust flap.

ihc95 · 08-04-2012, 07:18 PM

Quote:

Originally Posted by Zebra99

If you have a JB4 you can have canflap open at all times.

If you are concerned with the clanking it's just the car getting warm. Once it's warm flap opens and noise should go away.

If you have the noise at all times than yes golf-t if the above doesn't apply to you.

Just make sure it's not your WG lol, cuz those things rattle like bi*ches on almost every 335!

+1 my exhaust always rattles when I first turn the car on but goes away in about 30 seconds.

egregor · 08-06-2012, 01:07 PM

What else could that line do besides open/close the flap? The vacuum line is connected directly to the flap and appears to have no other function.

I plugged up the line and i have to say I am very pleased with the results. No more rattle, and a nicer exhaust sound as a bonus. My car is stock so canflap isn't an option.

08-02-2012, 11:34 AM	#1
egregor Private 5 Rep 67 Posts Drives: 2007 335i sedan Join Date: May 2012 Location: United States iTrader: (0)	Exhaust flap rattle fix? After about 20 seconds from starting the car, my exhaust makes the "coin clanging around a a coffee can" sound, and my exhaust becomes a bit louder. If i'm understanding these forum posts correctly, this is due to a loose/malfunctioning exhaust flap in the driver's side pipe, correct? If so, there have been 3 approaches I've seen to deal with it: Golf tee/zip tie the vacuum line, unplug the unit from the trunk, or replace the pipe/go aftermarket. Is there really no official fix for this so I can not run the risk of throwing codes, failing emissions, losing HP, or facing any other unintended consequences that BMW so clearly tried to avoid by putting this assembly there in the first place? Obviously these pipes didn't come from the factory like this, isn't there a DIY or something for just.. fixing the problem, or is that not possible?
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08-02-2012, 05:28 PM	#2
longliven54 Lieutenant 14 Rep 455 Posts Drives: 2007 335i e90 auto Join Date: Jan 2011 Location: victoria iTrader: (6)	Do The golf tee mod, and forget about the rest. You are over-thinking about the possible consequences and codes and what not __________________ JB4 G5 / VRSF IC / STETT CAI / GREDDY / custom exhaust / iRotora cross drilled rotots / snow stage 3 meth / 19" iForged senekas / upgraded speakers n CF woofer box / M3 bits/ DINAN camber plates/ KONI/ megan racing toe arm/ supreme power lowering perch
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08-04-2012, 01:19 PM	#3
egregor Private 5 Rep 67 Posts Drives: 2007 335i sedan Join Date: May 2012 Location: United States iTrader: (0)	shrug fair enough. Golf tee it is!
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08-04-2012, 05:48 PM	#4
Zebra99 Colonel 112 Rep 2,856 Posts Drives: 2011 335is E93 Join Date: Aug 2011 Location: Ontario iTrader: (6) Garage List 2008 BMW 335i E93 [10.00]	If you have a JB4 you can have canflap open at all times. If you are concerned with the clanking it's just the car getting warm. Once it's warm flap opens and noise should go away. If you have the noise at all times than yes golf-t if the above doesn't apply to you. Just make sure it's not your WG lol, cuz those things rattle like bi*ches on almost every 335!
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08-04-2012, 07:08 PM	#5
boostaholic786 Captain 40 Rep 623 Posts Drives: E92 N54 with MHD Custom flash Join Date: Dec 2011 Location: Plano TX iTrader: (0)	You need to enable the CAN flap on the JB4 to where it stays open all the time. I personally dont like unplugging plugs that do more than just control the exhaust valve. As far as I know. I remember somebody saying something about that it has more features than just opening and closing the exhaust flap. __________________ [SIZE="2"]Crimson Red E92 335i M-sport 6-speed with MHD custom stage 2+ flash only , 40% E85/93 mix,+ HRE P40S wheels, KW Clubsport, M3 sways,+BMW performance CF Mirrors, BMW Performance CF deck lid spoiler,+ CF interior trim, p3 vent boost gauge,+ LUX angel eyes (11.73@124mph on street tires)
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08-06-2012, 01:07 PM	#7
egregor Private 5 Rep 67 Posts Drives: 2007 335i sedan Join Date: May 2012 Location: United States iTrader: (0)	What else could that line do besides open/close the flap? The vacuum line is connected directly to the flap and appears to have no other function. I plugged up the line and i have to say I am very pleased with the results. No more rattle, and a nicer exhaust sound as a bonus. My car is stock so canflap isn't an option.
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