Exhaust rasp has gone after air inlet changed.2.2i

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ladders
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Exhaust rasp has gone after air inlet changed.2.2i

Post by ladders »

hi,
Indy changed cracked air inlet boot(downstream Maf). He couldn't buy exact boot,so he fitted one without a bottom bellows(2inch dia)which was fitted to a box adjacent main air box,which didn't appear to do anything.But now it has lost its lovely rasp on acceleration.Is this possible or is it a coincidence?
My car is a 2001 2.2i z3roadster
gookah
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  Z3 roadster 2.8

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by gookah »

These are still available from dealers and off ebay,
don't understand why he said they are not available, unless he couldn't be bothered to get one and is stringing you a line.....
see here:

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Z3 1.9 Sport Progress Journal (Wifey's)

I have an element of 'M-styling' on my car, If that's a good enough reason for the manufacturers to adorn a 320 with the M badge, then its certainly a good enough reason for me..
ladders
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by ladders »

My Indy fitted a new boot- part number 13541705209 but is not the same as the original. Yet the dealers got the part number from the chassi and the registration.Now that he has got the old boot he will take it to the dealers to get a exact match.
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pingu
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  M roadster S50

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by pingu »

Most people hear induction roar and think that it is exhaust roar.

Induction roar is actually a bad thing - performance wise. It is caused by turbulent air in the intake system.

Now that your system has been repaired and the leak has been cured, the flow will be be efficient as it won't be interrupted by air from the leak causing turbulence.

Think of it like a river that has a stream flowing into it. You can hear the water mixing as the stream flows into the river. Now the stream has been dammed and the river can run more efficiently.
Pingu
ladders
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by ladders »

Initially the car had poor performance,but occasionally it would fly plus a rasping exhaust.I took it to my Indy and he found cracks in the bellows of the upper air inlet boot, so he poured supaglue into the cracks ,the car was transformed.Bags of power and that lovely exhaust rasp.So he booked me in to have the upper boot replaced.He had already sent back a boot that was not Oem .The new boot has one branch off for vaccum use.The old one has two branches off,one for vaccum and the other is fed into a closed box.
Brian4
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  Z3 roadster 3.0i
Location: Hinckley

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Brian4 »

I would think the one to the closed box goes to the flap in the exhaust which opens under full load. ie high vacuum in the inlet.

http://www.realoem.com/bmw/enUS/showpar ... Id=18_0383
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peter2b
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  Z3 roadster 2.2i
Location: cheshire

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by peter2b »

my z3 2.2 post face lift has a two parts of hose after the maf sensor, the 1st bit has a small pipe going to the air box the second part has a pipe that goes some where else (to dark to see where) but I think it goes to the top of the engine, on mine it had been running on some thing and had holes in it causing the engine light to come on(cleared by robert t, cheers) got a new one off eBay just got to fit it, don't know if I will get my rasp back as well as that had disappeared
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Smartbear
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Smartbear »

Brian4 wrote:I would think the one to the closed box goes to the flap in the exhaust which opens under full load. ie high vacuum in the inlet.

http://www.realoem.com/bmw/enUS/showpar ... Id=18_0383
We changed this part on our car, it's just a closed resonator box which made no difference when it was missing on our replacement pipe-our 2.2 doesn't have an exhaust valve either.
It sounds great all the time! :lol:
Regards
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Robert T
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Robert T »

Brian4 wrote:I would think the one to the closed box goes to the flap in the exhaust which opens under full load. ie high vacuum in the inlet.
It might well be a vacuum takeoff, but the exhaust flap is not operated by an increase in vacuum, but rather by an electric valve that cuts in at a given rev limit, thus allowing the vacuum to operate the flap.

On my car (M44 1.9) the small hose comes off the main air intake hose disappears under the intake manifold and according to RealOEM, connects to the fuel injection unit: http://bmwfans.info/parts-catalog/Z3-Ro ... ion_valve/

Cheers R.
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Del
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  Z3 roadster 1.9

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Del »

As said already, vacuum leak may provide an induction rasp but the combustion mixture will be weaker with too much air. A weak mixture = less power.
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Zed Free
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  Z3 roadster 2.2i

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Zed Free »

2.2 does not have the exhaust flap. Wide open all the time. Lovely sound To go with the lovely smooth engine.
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Brian4
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  Z3 roadster 3.0i
Location: Hinckley

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Brian4 »

Zed Free wrote:2.2 does not have the exhaust flap. Wide open all the time. Lovely sound To go with the lovely smooth engine.

Same as my 3.0 auto great sound 6 cylinders on song.
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Mr Silver
Joined: Wed 25 Feb, 2009 09:34
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  Z3 roadster 3.0i

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Mr Silver »

The 3.0 auto does have the exhaust flap, at least my 2001 certainly does.


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Brian4
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  Z3 roadster 3.0i
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Brian4 »

The plot thickens cos mine has the pipework and electric valve but no flap or actuator in the rear pipes. It is the original exhaust or at least a one piece exhaust and real OEM says that they are not fitted to auto cars. mine is a year 2000 model.
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Brian H
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  Z3 roadster 3.0i

Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Brian H »

Brian4 wrote:The plot thickens cos mine has the pipework and electric valve but no flap or actuator in the rear pipes. It is the original exhaust or at least a one piece exhaust and real OEM says that they are not fitted to auto cars. mine is a year 2000 model.
Mine does not have one either, where is the electric valve situated Brian?
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Robert T
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  Z3 roadster 1.9
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Robert T »

Brian H wrote:Mine does not have one either, where is the electric valve situated Brian?
It's me you need to be asking, Brian, as I brought it up. I believe it is in the boot somewhere. You can see it on the diagram here: http://bmwfans.info/parts-catalog/Z3-Ro ... #7810831_5

It list all kinds of models with the valves fitted, which is weird, as the 1.9 only has a single tailpipe! The main implication from the diagram is that it was fitted from September 1998 onwards. I honestly don't know which models got it.

Cheers R.
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Brian H
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Brian H »

Had a look at the link Robert, the valve is not on the list for my VIN.
Brian4
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  Z3 roadster 3.0i
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by Brian4 »

Robert why ask you when you don't know where it is.

The flap is in the well behind the left rear wheel. It is a small black box with 2 vac pipes and 2 wires. It works from the vacuum in the inlet manifold and the electric opens the valve to allow the vacuum to the flap valve on the right hand of the two tail pipes which in effect bypasses the rear silencer.

just been checking and the valve is he same as the one that operates the engine mounts on our 5 series.

real oem for my vin no
http://www.realoem.com/bmw/enUS/showpar ... Id=18_0383
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ladders
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Re: Exhaust rasp has gone after air inlet changed.2.2i

Post by ladders »

hi,my indi changed the air induction boot ...part number 13541435625 apparently made for the 5 series bmw.the rasp sound is back and so too is the power, am well pleased.
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