Emissions? bent pipe failure

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4wheels
Joined: Sat 24 Sep, 2016 20:42
Posts: 71

  Z3 roadster 3.0i

Emissions? bent pipe failure

Post by 4wheels » Wed 28 Sep, 2016 21:17

so, on my 2001 Z3 3.0 this pipe is pretty much useless, its got hot/old and feels a little like blue tac!

pretty sure this is just the emissions re-circ pipe? so i could remove it? and plug it up?
but, is that a good thing? anyone done it before?

4wheels
Joined: Sat 24 Sep, 2016 20:42
Posts: 71

  Z3 roadster 3.0i

Re: Emissions? bent pipe failure

Post by 4wheels » Wed 28 Sep, 2016 21:21

DSC_0459 - Copy.JPG
The picture i meant to post!
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NZ00Z3
Joined: Thu 23 Jun, 2016 02:26
Posts: 61

  Z3 roadster 3.0i

Re: Emissions? bent pipe failure

Post by NZ00Z3 » Wed 28 Sep, 2016 22:16

Yes its the secondary air pipe that goes between the pump and the valve on the engine. Secondary air only operates for about 30 seconds when the engine is started. Think of it as a system that produces a flame thrower that heats the cat's up really quickly to reduce emissions.

Should you remove it? Well that depends on the rules/laws where you live. If you have to do emission testing, then change the hose, it should not cost too much. If not, then you could remove it, pull the electric plug on the air pump and see if any CEL's or codes come up. The valve on the engine can fail open and kill the air pump, so putting a pug on the valve end would be a good idea. The valve is operated by a small vacuum line that runs behind the head to a solenoid. If the hose breaks, you'll have a vacuum leak during the first 30 seconds on engine run that may cause lean running conditions and be hard to fault find.

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pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3337

  M roadster S50

Re: Emissions? bent pipe failure

Post by pingu » Thu 29 Sep, 2016 12:50

NZ00Z3 wrote:Yes its the secondary air pipe that goes between the pump and the valve on the engine. Secondary air only operates for about 30 seconds when the engine is started. Think of it as a system that produces a flame thrower that heats the cat's up really quickly to reduce emissions.

Should you remove it? Well that depends on the rules/laws where you live. If you have to do emission testing, then change the hose, it should not cost too much. If not, then you could remove it, pull the electric plug on the air pump and see if any CEL's or codes come up. The valve on the engine can fail open and kill the air pump, so putting a pug on the valve end would be a good idea. The valve is operated by a small vacuum line that runs behind the head to a solenoid. If the hose breaks, you'll have a vacuum leak during the first 30 seconds on engine run that may cause lean running conditions and be hard to fault find.
Image

I suspect the silver thing at the end of the hose is a one-way valve.

If it is, I'm not sure that unpumped air would get into the exhaust, but if it could the exhaust gas will have more air and ECU will think the engine is running lean.

I agree with NZ about removing the complete system. I'm not sure on the legality of doing it, but if it were me... :wink:
Pingu

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Robert T
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  Z3 roadster 1.9
Location: Cheshire

Re: Emissions? bent pipe failure

Post by Robert T » Thu 29 Sep, 2016 14:20

My understanding is that the secondary air pump dilutes the exhaust gases with fresh air when the engine is cold, thus reducing the percentage of harmful emissions (not the quantity). The most common mode of failure seems to be that the valve fails and allows hot exhaust gases back up to the pump when the pump is not running. This can melt the hoses (which are designed to take cold air from the pump, not hot exhaust gases going in the opposite direction) and cause corrosion inside the pump rendering it useless. If gases are leaking from the exhaust system, then the lambda sensors will not be receiving all the exhaust gas and could give skewed readings (all the time, not just at startup). It is also likely to sound like the exhaust has a hole in it (because in essence, it has!).

I don't think there is any MOT requirement for this system in the UK, and you can probably just remove it, but you will need to install a blanking plate on the exhaust manifold in place of the valve. The only question-mark is over whether the ECU is aware of the pump and registers an error code that it is malfunctioning.

This thread should help you: viewtopic.php?p=354888#p354888

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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siwilson
Joined: Fri 19 Jun, 2009 10:54
Posts: 783

  M roadster S54
Location: Horley

Re: Emissions? bent pipe failure

Post by siwilson » Thu 29 Sep, 2016 21:30

It only works when the engine is cold. When are you ever going to get to the MOT centre with a cold engine? That said, I would fix it and not delete since you need to code it out of the DME to avoid a CEL
2001 M roadster S54 Laguna Seca Blue

gookah
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  Z3 roadster 2.8

Re: Emissions? bent pipe failure

Post by gookah » Fri 30 Sep, 2016 00:27

siwilson wrote:That said, I would fix it and not delete since you need to code it out of the DME to avoid a CEL
total rubbish :head:
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Z3 2.8 Progress Journal (Mine)
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..

alec.m
Joined: Tue 05 Oct, 2010 20:01
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  Z3 roadster 2.8
Location: Lymington

Re: Emissions? bent pipe failure

Post by alec.m » Fri 30 Sep, 2016 06:33

I had a pump failure on my 2.8 and was just going to remove the valve and put a blanking plate in its place but the indy that I use advised against that as the ECU would throw up faults. I managed to get a second hand pump to resolve the issue, new ones are serious money.
I don`t think there would be any problem regarding MOT emissions in this country. I have a 3.0 now which has no pump but some 3.0s do have a pump. I`ve read they were put on for the American market where emissions are stricter.

4wheels
Joined: Sat 24 Sep, 2016 20:42
Posts: 71

  Z3 roadster 3.0i

Re: Emissions? bent pipe failure

Post by 4wheels » Sat 01 Oct, 2016 17:30

Thought as much. Seems pointless to carry the weight of it around for just start up. I'll remove it tomorrow when it stops raining.

New pipe is something like 45 quid!!!

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stevov
Joined: Sun 21 Dec, 2014 15:56
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  Z3 roadster 2.0
Contact:

Re: Emissions? bent pipe failure

Post by stevov » Sat 01 Oct, 2016 21:46

Removed the lot, made a blanking plate, plugged vacuum line, tied up electrical connector. No codes job done. Simples :D

siwilson
Joined: Fri 19 Jun, 2009 10:54
Posts: 783

  M roadster S54
Location: Horley

Re: Emissions? bent pipe failure

Post by siwilson » Sun 02 Oct, 2016 15:32

gookah wrote:
siwilson wrote:That said, I would fix it and not delete since you need to code it out of the DME to avoid a CEL
total rubbish :head:
e

Charming. Mine accidentally became disconnected due to the ground wire coming loose and that it threw a CEL. Perhaps the M54 reacts slightly differently to an S54. I don't know. Still I would not call it total rubbish and I would still fix it.
2001 M roadster S54 Laguna Seca Blue

gookah
Z Register member
Joined: Thu 07 Aug, 2008 10:51
Posts: 2727

  Z3 roadster 2.8

Re: Emissions? bent pipe failure

Post by gookah » Sun 02 Oct, 2016 16:59

siwilson wrote:
gookah wrote:
siwilson wrote:That said, I would fix it and not delete since you need to code it out of the DME to avoid a CEL
total rubbish :head:
I don't know. .
I do :thumb:
the link is to my write up after doing the job... :D
Last edited by gookah on Mon 03 Oct, 2016 11:39, edited 1 time in total.
Image

Z3 2.8 Progress Journal (Mine)
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..

4wheels
Joined: Sat 24 Sep, 2016 20:42
Posts: 71

  Z3 roadster 3.0i

Re: Emissions? bent pipe failure

Post by 4wheels » Sun 02 Oct, 2016 19:45

had a better look today, doesnt look like any air is going through that pipe, hot or cold.
the pump kind of ticks rather than makes a pumping sound.... so i guess thats fried anyway!

soon as i get chance ill make a plate and remove the lot

im guessing the rest of the vacuum pipes (little ones) are equally as old and powdery as that one and probably dont work anyway. ill have to replace them i guess.
what else runs off the vacuum? brake servo? anything else?

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