Badger5Chris Nott
Results 1 to 15 of 15
  1. #1
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287

    Where does the combi valve vac hose go?

    It's disconnected on my car. Should the hose be plugged back in? If not, should it be plugged as it isn't currently?

  2. # ADS
    ADS
    Join Date
    Always
    Location
    Global
    Posts
    Many
     
  3. #2
    Dani_B19's Avatar
    Audi-sports own special child.

    Status
    Online
    Join Date
    Nov 2008
    Location
    Barnsley
    Posts
    7,233
    It should be connected under the inlet manifold manifold off a small vac nipple. If its not then you need to find out whats on that nipple
    Driving the most secretive S3 on ASN

  4. #3
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    Quote Originally Posted by Dani_B19 View Post
    It should be connected under the inlet manifold manifold off a small vac nipple. If its not then you need to find out whats on that nipple
    Damn. I don't know where to start then, as I was looking at it tonight and couldn't see where it would go. I need pictures lol.

    In this photo from the other thread:
    20131208_125709.jpg
    you can see the hose from the inlet to the DV. I *THINK* that the hose from the FPR is going to the inlet next to where the DV hose goes. Does that sound correct so far?

    You will also see the black hose going into the t-piece on the DV hose. I do not know where this black hose goes, what it's for or why its plumbed into the DV hose. Perhaps this goes to where the combi valve hose should go?

    Is there any good reason to do this?

  5. #4
    <tuffty/>'s Avatar
    Badger 5 Edition

    Status
    Online
    Join Date
    Sep 2008
    Location
    Gloucestershire
    Posts
    15,553
    Looks like a fairly poorly executed N249 bypass... there is a guide in the FAQ sticky that could help you tidy it up a but... APY engines are a little more involved as they have secondary air (the pipe loitering about off the jobber on the side of the head...) most peeps just remove this altogether to simplify the whole thing... later AMK/BAM S3's didn't come with SAI... its an emissions thing... won't affect MOT as its more for controlling emissions on cold start...

    Look in the FAQs and have a read of the N249 bypass/delete thread...

    Couple of reasons for doing this... makes the DV more responsive and cleans up a lot of the pipes that can split etc and cause other running issues... however... there is no real need to do it if you don't want/need to... most people do it as they are getting rid of split pipes etc already so a full clean up of stuff and replacement with silicon just makes it easier...

    The N249 is used as part of the ECU protection functionality... its a switch over valve... the DV is opened by vacuum and kept closed by boost... if the ECU detects an issue then it can use the N249 to switch to a vacuum feed from the vacuum store (plastic container that is missing from your picture) and operates the DV to dump boost while closing the throttle to reduce load...

    You lose this with the bypass but tbh the ECU can hold its own without it... biggest issues being more leaks and bad maps... I'd be more concerned about leaks and bad maps than re-plumbing the N249 back in..

    You do need to leave it electrically connected though as this messes with adaptions and can make the car fail emission test at MOT time

    <tuffty/>
    Silver 2001 AMK S3. Silver alcantara interior... now with added powarrrrrrrr, torques. VAGCOM + KII-USB. >> My build thread...

  6. #5
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    Thanks Tufty. I've actually read through that, but thought I didn't need it as a result of this already being bypassed. Should I be looking for somewhere to plug this combi valve back in?

    I'll go back through that thread if you say it is going to yield the answers I need, but I could have sworn there was no mention of the vac hose for the combi. It is possible I am going mad, what with the amount of stuff I am having to jump on with this car all at once!

  7. #6
    <tuffty/>'s Avatar
    Badger 5 Edition

    Status
    Online
    Join Date
    Sep 2008
    Location
    Gloucestershire
    Posts
    15,553
    Lets get the terminology straight here... by 'combi' valve I am assuming you mean the grey valve in the centre of your pic above... if so this is the N249 valve

    The valve just needs to be plugged in electrically (as it is currently)... no need to pipe this up at all as this is now 'by passed'... just cable tie it out the way..

    <tuffty/>
    Silver 2001 AMK S3. Silver alcantara interior... now with added powarrrrrrrr, torques. VAGCOM + KII-USB. >> My build thread...

  8. #7
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    Quote Originally Posted by <tuffty/> View Post
    Lets get the terminology straight here... by 'combi' valve I am assuming you mean the grey valve in the centre of your pic above... if so this is the N249 valve

    The valve just needs to be plugged in electrically (as it is currently)... no need to pipe this up at all as this is now 'by passed'... just cable tie it out the way..

    <tuffty/>
    Ah no, I know what the N249 valve is (now, thanks to you guys on here!), no what I mean is the round item to the right of the FPR. It has a dark vac hose connected to it that isn't going anywhere now. I thought it was an EGR originally but then saw it referred to as a combi valve a couple of times during searches. Seems I may have got my wires crossed on its name.

  9. #8
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    Anymore for anymore?

  10. #9
    <tuffty/>'s Avatar
    Badger 5 Edition

    Status
    Online
    Join Date
    Sep 2008
    Location
    Gloucestershire
    Posts
    15,553
    Thats the Secondary Air Injection valve... bin it off...

    <tuffty/>
    Silver 2001 AMK S3. Silver alcantara interior... now with added powarrrrrrrr, torques. VAGCOM + KII-USB. >> My build thread...

  11. #10
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    You beat me to it! Just discovered that from here:
    N249 Bypass How To (2000 S3 - but same for many)

    So what's its use? When you say "bin it off", how? Remove it from the car completely? What's the benefit/downside to doing so?

  12. #11
    <tuffty/>'s Avatar
    Badger 5 Edition

    Status
    Online
    Join Date
    Sep 2008
    Location
    Gloucestershire
    Posts
    15,553
    Quote Originally Posted by Bad Sir Culation View Post
    You beat me to it! Just discovered that from here:
    N249 Bypass How To (2000 S3 - but same for many)

    So what's its use? When you say "bin it off", how? Remove it from the car completely? What's the benefit/downside to doing so?
    Sai removal guide

    Its used for emissions on cold start... binning off means less clutter, less pipes etc to leak, less to go wrong

    <tuffty/>
    Silver 2001 AMK S3. Silver alcantara interior... now with added powarrrrrrrr, torques. VAGCOM + KII-USB. >> My build thread...

  13. #12
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    Thanks Tuffty, much appreciated. It's far easier to find these guides when you know what the parts are actually called!

  14. #13
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    Just one more quick question; if I leave the valve in place for now, should I plug the vac line on it, or just leave it unplugged?

  15. #14
    1st Gear

    Status
    Offline
    Join Date
    Nov 2011
    Location
    Leeds, UK
    Posts
    287
    Bump in case anyone can answer this for me.

  16. #15
    4th Gear

    Status
    Offline
    Join Date
    Aug 2011
    Location
    Plymouth
    Posts
    744

    My Social Networking

    Add Lavis89 on Facebook
    If the car is running right and there isn't a check engine light then I would leave it for the moment until you do a SAI removal (if you do one). That's just me though, I don't like to fiddle with things that aint broken because I will tend to brake it!
    2001 1.8T Quattro Sport 89k covered ARY engine.
    Remapped at Badger 5, 213bhp - 235lb/ft torque.
    HS2K cone, FMDV008, Silicon TIP, 18" RS4 (reps), AP coilovers, Catch can, n249 bypass, Toyosport 3" Downpipe/Decat, S3 Front brakes, Polyflexed Dogbone, S3dave adjustable tie bars

    Soon to be done: SAI delete, Install the toyosport FMIC i have kicking about in my living room

 

 

Similar Threads

  1. where does the rear washer line run on an avant?
    By jcb in forum A4/S4 forum(B5 Chassis)
    Replies: 7
    Last Post: 2nd January 2009, 23:59
  2. where does the factory sub plug in in my a3??? RACKING MY BRAIN BIG TIME
    By samthomas33 in forum A3/S3 Forum (8L Chassis)
    Replies: 1
    Last Post: 21st March 2008, 11:34
  3. where does the auto gearbox oil go?
    By shufti in forum A6/S6/Allroad forum (C5 Chassis)
    Replies: 1
    Last Post: 23rd July 2007, 15:40
  4. where does the clutch cable attach to the engine
    By nick1973 in forum A3/S3 Forum (8L Chassis)
    Replies: 3
    Last Post: 29th December 2006, 20:43
  5. Where is the diverter valve on an A4
    By brookescourt in forum A4/S4 forum(B5 Chassis)
    Replies: 4
    Last Post: 10th November 2003, 16:30

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO