Exhaust "flap" stuck open - issue?

Scania

Scania

Scania

Caporegime
Joined
25 Nov 2004
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25,973
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On the road....
The 328's and 323's have a dual stage exhaust that is actuated via a vacuum routed from the intake manifold. In the center most tailpipe with the car idling, you can look in and see a small flap, which when working properly will appear closed. It activates once you pass 2500RPM, in which a vacuum is added from a line that runs under the car and to the intake manifold, and forces the flap to open allowing a near straight shot from the cats. The sole purpose of this is to quiet the car down at idle.
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I've always found mine to sound quite quiet. So I assumed mine was actually stuck closed or something.....

Anyway,with me being off work this week,I have been giving the car its first clean of 2010! :o - I may post some before & after pics later.... :D - and I decided to have a look and my exhaust flap and it appears to be stuck open.....!
exhaust1.jpg



Reading this thread - http://www.e36-tech.com/forum/diy-328i-323i-golf-tee-mod-3402.html - I'm unconvinced if this is a major issue or not given that some people use whats knows as the "Golf Tee mod" to make the thing open all the time.
Should I try to get this fixed? - the various hoses seem to be where they should be, the car runs fine (I hate saying that when the car in question is 14years old!) and passed its MOT yesterday.

Its supposed to quieten the car on idle, yet mine idles very quietly, too quiet for a 2.8 i6 imo! :D

Leave it or fix it, and if fix it, any ideas how? - the flap is not stuck, it moves if you prod it with a screwdriver, its just open all the time....

:)
 
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Won't make any difference being stuck open, other than noise. Leave it.

If you really want to fix it, seems to close with vacuum applied to the acutator, which is drawn from the inlet manifold. If you really must fix it, I'd be inclined to unplug the hose and see if you can feel any suck on the hose when car is idleing, might be worth using a mityvac on the acutator itself to see if it closes. Beyond that, I'm guessing it's probably solenoid related, and not worth anymore effort
 
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I had the opposite, mine was stuck shut and i was convinced my cat was blocked. it wasnt untill my rear difuser went missing i noticed the pipe was broke. All better now.
 
sod the flap, leave it open

go back to the inlet manifold and find the vac hose tho. its probably been disconnected. a vac leak is bad and will loose performance
 
numnutz said:
Won't make any difference being stuck open, other than noise. Leave it.

If you really want to fix it, seems to close with vacuum applied to the acutator, which is drawn from the inlet manifold. If you really must fix it, I'd be inclined to unplug the hose and see if you can feel any suck on the hose when car is idleing, might be worth using a mityvac on the acutator itself to see if it closes. Beyond that, I'm guessing it's probably solenoid related, and not worth anymore effort
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Had a good look at the manifold (and found a dead Mouse!) everything is as it should be - bar the stiff! :D - as for noise, if anything I'd like it if it was stuck so I could open it to make it a bit louder! :D :D

I'm averaging 28mpg from it & it goes like a scalded Cat! so I don't think I'm losing any performance or economy,it would be nice to find something was wrong and gain a bit I guess!

As I say though, I can't find any signs of disconnected hoses etc - I'm probably looking at the wrong one.
 
You won't lose performance.

The idea of the flap is that in town driving your exhaust note is quite, then when you're giving it some it is allowed to breath better. It opens at ~2.5k-3k rpm but it is often modified to be stuck open. Normally the vaccum pipe is disconnected and a screw is placed in it instead. Mine though was some how wedged open, didn't effect anything. :)
 
Fair enough, sod it then! :D

I read about the screw or golf tee mod invader, and mines not been done - Given the previous owner was a retired disabled Doctor, I'd have been a bit surprised it if had been modded!

The hoses etc are where they should be. :)

Thanks for the input chaps. :)
 
godinman said:
Does it close when you start the engine?
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Hmm, it may well do come to think about it - I've not started it today and did not think to actually try this.... :o

My car has always started with a bit of a "rasp" when it fires, and the exhaust burbles for 5 seconds or so and then it is very quiet.

Its dark outside, so I'll check it tomorrow and have a look. :)
 
( |-| |2 ][ $;16073646 said:
When it's working wont the extra back pressure help with torque below 2.5k?
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Mine feels fine, and I often keep it well below 2500 rpm cruising to & from work.....


Over Clocker said:
It will be open when the car is off. You need to check if a minute after starting it mate :)
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Will do, the more I think about it, the more I'm thinking that as said, it closes once the car starts?

The sound mine makes after initial startup sounds lovely, as soon as you drive off, you can barely hear it.... :(

I'll be doing some experimenting tomorrow....... :D
 
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Why doesnt mine have a cool exhuast valvey thing.


It just has an absolutely huge stupid exhuast which makes no noise at all.
 
[TW]Fox;16076230 said:
Why doesnt mine have a cool exhuast valvey thing.


It just has an absolutely huge stupid exhuast which makes no noise at all.
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Do the later(?) e39 sports with the "round hole" visible style of exhaust (if you know what I mean!) make any better sound? - I'd guess not due to EU rules & noise regs killing car sounds... :(

Phate said:
lol, flap



:p
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I'm stunned this did not come until post #17, we must be slacking in here.... ;) :D
 
R420LA6X2/4MNA said:
Do the later(?) e39 sports with the "round hole" visible style of exhaust (if you know what I mean!) make any better sound?
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Nope, the exhuast makes no noise whatsoever.

This contrasts with the 330Ci and the Z4 3.0i which both have a rather nice sounding exhaust.

My quest to find somebody who can fit a custom exhuast which sounds exactly like a 330Ci has so far not been succesful. They all seem to do MASSIVE NOISE MAN.
 
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