340I exhuast noise on start up

recardo · 12-02-2016, 12:14 PM

Can anyone tell me how or what makes the exhaust louder and fruitier on start up on the 340i than it is in when sport mode / flap mod done?

CazuaLLUK · 12-02-2016, 12:33 PM

Adding an MPPSK kit!

ronime · 12-02-2016, 01:16 PM

In another thread it was mentioned that the turbo wastegate is held open on startup to help the catalytic converters get up to working temperature quickly.

Our 320i seems to exhibit the same behaviour.

225 · 12-02-2016, 01:39 PM

Quote:

Originally Posted by ronime

In another thread it was mentioned that the turbo wastegate is held open on startup to help the catalytic converters get up to working temperature quickly.

Our 320i seems to exhibit the same behaviour.

this I belwive. Its definately not the left exhaust flap!

recardo · 12-02-2016, 01:48 PM

Quote:

Originally Posted by 225

this I belwive. Its definately not the left exhaust flap!

didnt think it was, my flaps' permanently open (insert Viz joke).

Was curious as to what else would adding to the warm up noise - wastegate makes sense, thanks!

scottc · 12-02-2016, 02:51 PM

Think it must have the cold start like my M4, fecking loud when it first starts..

Daftasabrush · 12-02-2016, 06:10 PM

The 340i is pretty stupid on startup, MPPSK makes it a little louder but not hugely IMO.

Gripen · 12-03-2016, 03:28 AM

My 320i sounds like it had a big hole in the exhaust, it disappears after few minutes

Mr.G20 M340 · 12-03-2016, 04:56 AM

I did a muffler and resonator delete on my 340 and I love cold starts, especially when I do it at school and make all the alarms go off lol..

ronime · 12-03-2016, 07:38 AM

Quote:

Originally Posted by Gripen

My 320i sounds like it had a big hole in the exhaust, it disappears after few minutes

I had a similar nagging doubt but it does seem to be by design.

FarmerD · 12-03-2016, 11:45 AM

It's to do with the car needing to warm the cat up quickly. As my engine engineer mate told me, they retard the ignition for a short period of time and pump extra fuel into the engine so that it burns late, and slightly into the exhaust manifold. Not very efficient in itself but worth it on balance to preheat the cat

sahajesh · 12-04-2016, 05:11 AM

Quote:

Originally Posted by Mr.F30

I did a muffler and resonator delete on my 340 and I love cold starts, especially when I do it at school and make all the alarms go off lol..

It may be because it's in a garage and the sound is echoing but it just sounds like there's a hole in the exhaust

:

Panchoa · 12-04-2016, 08:21 AM

Quote:

Originally Posted by sahajesh

It may be because it's in a garage and the sound is echoing but it just sounds like there's a hole in the exhaust

:

Thats exactly what i was thinking

sahajesh · 12-04-2016, 08:22 AM

Quote:

Originally Posted by Panchoa

Quote:

Originally Posted by sahajesh

It may be because it's in a garage and the sound is echoing but it just sounds like there's a hole in the exhaust

:

Thats exactly what i was thinking

Sounds worse than a diesel!

daveuk340 · 12-05-2016, 05:57 AM

I love the noise on start up and then it settles down to a disappointingly quiet sound

12-02-2016, 12:14 PM	#1
recardo Private 22 Rep 66 Posts Drives: 340i M-Sport Touring Join Date: Sep 2016 Location: Ayrshire iTrader: (0)	340I exhuast noise on start up Can anyone tell me how or what makes the exhaust louder and fruitier on start up on the 340i than it is in when sport mode / flap mod done?
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12-02-2016, 12:33 PM	#2
CazuaLLUK Banned 2221 Rep 5,897 Posts Drives: 2014 335i Black F30 M Sport Join Date: May 2016 Location: Portsmouth, UK iTrader: (1) Garage List 2014 BMW 320d F30 [10.00]	Adding an MPPSK kit!
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12-02-2016, 01:16 PM	#3
ronime Captain 344 Rep 834 Posts Drives: BMW X1 sDrive20i M Sport MHT Join Date: Aug 2016 Location: West Yorkshire, UK iTrader: (0)	In another thread it was mentioned that the turbo wastegate is held open on startup to help the catalytic converters get up to working temperature quickly. Our 320i seems to exhibit the same behaviour. __________________ BMW X1 sDrive20i ///M Sport MHT
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12-02-2016, 02:51 PM	#6
scottc Lieutenant Colonel 699 Rep 1,641 Posts Drives: Mercedes E350 Cpe Join Date: May 2007 Location: UK iTrader: (0)	Think it must have the cold start like my M4, fecking loud when it first starts.. __________________ C63 Coupe
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12-02-2016, 06:10 PM	#7
Daftasabrush Fool 1857 Rep 3,542 Posts Drives: F31 340i Join Date: Jul 2014 Location: England iTrader: (0)	The 340i is pretty stupid on startup, MPPSK makes it a little louder but not hugely IMO.
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12-03-2016, 03:28 AM	#8
Gripen New Member 3 Rep 25 Posts Drives: BMW 320iX Join Date: Sep 2015 Location: UK iTrader: (0)	My 320i sounds like it had a big hole in the exhaust, it disappears after few minutes
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12-03-2016, 04:56 AM	#9
Mr.G20 M340 Captain 222 Rep 771 Posts Drives: 2020 Portimao Blue M340-x Join Date: Dec 2013 Location: Los Angeles, CA iTrader: (0)	I did a muffler and resonator delete on my 340 and I love cold starts, especially when I do it at school and make all the alarms go off lol.. __________________ Instagram: Bmw_Captivate 2020 Portimao Blue M340 X Drive and adaptive suspension. Mods: custom exhaust, VRSF Catted DP, Injen intake and Chargepipe.
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12-03-2016, 11:45 AM	#11
FarmerD Second Lieutenant 73 Rep 298 Posts Drives: M340i Touring Join Date: Dec 2015 Location: Warwick iTrader: (0)	It's to do with the car needing to warm the cat up quickly. As my engine engineer mate told me, they retard the ignition for a short period of time and pump extra fuel into the engine so that it burns late, and slightly into the exhaust manifold. Not very efficient in itself but worth it on balance to preheat the cat __________________ M340i Touring - Tanzanite, sunroof, tech pack, visibility pack, comfort pack… Z4 Coupe 3.0si - Stratus Grey, ST XTAs, Eisenmann, PSD Short Shift, Xenons, New England Leather
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12-05-2016, 05:57 AM	#15
daveuk340 Enlisted Member 10 Rep 34 Posts Drives: BMW 340i Join Date: Sep 2015 Location: Brentwood iTrader: (0)	I love the noise on start up and then it settles down to a disappointingly quiet sound
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