1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Catch Can 1 way check valve query

Discussion in 'A3/S3 Forum (8L Chassis)' started by JtotheD, Aug 6, 2012.

  1. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    Just a quick question - fitted my catch can yesterday to my S3 and didn't fit a 1 way check valve into the brake servo line. car runs really rich, huntsto start with then revs up to 2000 rpm and stays there with loud sucking noises from the tip, is in limp mode, backfires all the time and when you get below 2000 rpm ish it starts hunting and then pressing the throttle does nothing. you have to turn the car off and on again to get throttle response back

    vcds shows throttle actuator 2 sensor fault and something about a throttle alignment fault sorry to be so vague. anyway, took my throttle body out, cleaned it and put it back in, still the same - performed the realignment on vcds and it just shows error.

    tried a different throttle body and got the same results. smoke tested the system and smoke was pouring out the catch can system, so tightened everything up and that illiminated that (the leak) but it still runs as already explained. have another throttle body on the way to me as we weren't completely sure the one we used to test it (out of a leonn cupra r) was working correctly either because the engine has died!

    however my question is, sorry if this sounds retarded, could not having a check valve in the brake servo (or something else i may have missed when doing the catch can - i have gone back through all the instructions numerous times thinking what i could have missed or not put back in etc and the brake servo check valve is the only thing i can think of ) cause the car to run like this and throw up those fault codes as its over compensating for something?? or is it complete coincidence that the throttle body dying has caused all this and that the catch can system is ok?? my engine is a BAM by the way. Josh
    #1
  2. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    On an S3 the check valve is right next to the servo wrapped in a bit of heat wrap (secured with poppers)

    How have you fitted the pipework exactly and what did you remove?

    Has all the signs of a large vac leak

    <tuffty/>
    #2
  3. Westy
    Offline

    Westy Double Dark Side! Diesel & 8P

    Joined:
    Dec 2, 2008
    Messages:
    17,295
    Likes Received:
    969
    I'm sure in my catch can guide I stressed as muh as possible how important the 1 way valve is. Why did you think it wouldn't matter?!!
    #3
  4. Westy
    Offline

    Westy Double Dark Side! Diesel & 8P

    Joined:
    Dec 2, 2008
    Messages:
    17,295
    Likes Received:
    969
    The first time I fitted a catch can to mine, the bung I used in the big nipple under the inlet manifold had fallen out and I got some pretty rough idling.
    #4
  5. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    The one way for the servo in not needed where I originally had it... when I first did mine I didn't realise that the servo valve was actually by the servo so I fitted another valve in the pipe as it came off the inlet... this is not needed...

    When removing all the pipes under the inlet mani you must make sure all outlets that are not being used are blocked off properly... when removing the PCV stuff ideally you would replace the PCV valve and rubber t-piece that is under the mani with a straight piece of rubber or take the catch can feed from the block straight off the elbow

    If not venting the catch can back into the TIP (and why would you lets face it) you need to block off the inlet to the TIP where the PCV used to go

    <tuffty/>
    #5
  6. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    kept the hockey puck accumulator and the bit that goes in the crank case/lower breather pipe on the oil filter housing with the o ring. removed the hard pipe brake booster line, and the rest of the pcv system including the t piece which i'm assuming housed the pcv valve. then bunged the nipple underneath the centre of the intake manifold, capped the brake booster line, (i;m sure i did this!) ran piping from catch can to the hocky puck into the t piece which sends one pipe off the bit on the side of the rocker cover and the other bit of the t piece into the lower breather pipe on the oil filter housing etc with the o ring and kept in by a green c clip.
    #6
  7. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    it's not i thought it wouldn't matter - honestly after reading your guide numerous times and getting everything ordered up i completely forgot about it. ridiculous as it sounds that's what happened. despite trying a few things now i'm not the most mechanically minded yet and so it slipped my mind and it's taken me til now after retracing all steps etc to realise i never put one in etc
    #7
  8. Westy
    Offline

    Westy Double Dark Side! Diesel & 8P

    Joined:
    Dec 2, 2008
    Messages:
    17,295
    Likes Received:
    969
    Have you kept hold of the original one that you removed as you can re use that.

    As tuffty said, are all TIP ins/outs blocked off?
    #8
  9. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    the original check valve? or pcv valve? if, like tuffty says the original check valve is housed by heat wrap in poppers then i've done nothing to it and it is still as factory, if you mean the pcv valve yes i still have the whole system, found some nice split pipes though!
    #9
  10. Westy
    Offline

    Westy Double Dark Side! Diesel & 8P

    Joined:
    Dec 2, 2008
    Messages:
    17,295
    Likes Received:
    969
    No I meant the check valve. I've never run my system without a check valve so I'm not sure how it would behave but if I was you I'd try refitting it to see if it helps.

    Check the pics on the thread again and you'll see that the original valve has a fork in it so 1 part will need blocking off. It's all in that thread mate.

    Go over ever inlet/outlet and make sure everything that's meant to be blocked off is blocked off tightly.
    #10
  11. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    Ok... fitting a catch can and doing the PCV and other paraphernalia delete is shockingly easy but just looks a bugger due to all the pipes involved..

    Basically...
    Remove all this from under the inlet except for the 90 deg elbow coming out the block...
    [​IMG]

    You will be left with a large vac outlet where PN 06A 133 783 AS was connected and the 'servo' pipe outlet...

    Block the centre vac outlet under the mani (in this pic I have used it to feed my super size DV but have since blocked it off)
    [​IMG]

    Once you have removed the 'U' shaped servo pipe from the hard pipe part circled in red in the 'pipes' picture connect this directly to the outlet on the side on the inlet like I have in the pic below (bottom left)
    [​IMG]

    That should sort all the vacuum related stuff out... now the catch can...

    There are a couple of ways this can be connected but essentially you are trying to do the following... you need to feed one side of the catch can from both the 90 deg outlet from the block (06A 103 213 F in the top pic) and the outlet from the top of the cam cover (normally has the funky shaped 3 prong rubber jobber on it)... the other side of the catch can (assuming its a two outlet type) can either go back to the TIP (normally via the hockey puck valve) or to atmosphere with a filter attached..

    If going to atmos then you must block off the TIP where the original pipe was

    <tuffty/>
    #11
  12. vrbob
    Offline

    vrbob Thats no Moon, Thats a space station!

    Joined:
    Jun 19, 2007
    Messages:
    2,364
    Likes Received:
    157
    Am sure you will get to the bottom of this Josh and will give you a hand one night if you need some more help etc.

    I think getting a new throttlebody isnt a bad thing and its not to bad for £40 so use that and re trace all the steps as pointed out above and we will have you back up and running asap :)
    #12
  13. superkarl
    Offline

    superkarl MAN OF STEEL

    Joined:
    Mar 28, 2010
    Messages:
    7,553
    Likes Received:
    1,074
    tuffty the U shaped servo pipe, me and westy both have one way check valves in there.

    where is yours?
    i thought this was needed as part of the catch can install. i even fitted it the wrong way initially and had no brakes lol
    #13
  14. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    No need for a check valve there (I did fit one there originally) as there is a valve next to the servo behind the heatshield just to the right of the plug for the lambda..
    [​IMG]

    ...and my servo pipe looks like this...
    [​IMG]

    <tuffty/>
    #14
  15. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    just went and got my pvc system from tom's and after a quick chat we think this has all sprung from not having the check valve in the brake pipe and as air can go both ways through the pipe causing the butterfly vavlve in the throttle body to play up also. so i will refit the oringal check valve from the pcv system into the bit where the the brake servo pipe goes from the manifold and round from there.

    so i will have manifold - brake servo pipe - check valve - brake servo pipe . like your last pic tuffty showing your brake servo pipe and the difference in mine will be that in that U bend i will reinsert the check valve...

    thanks though everyone for your opinions/comments/help etc.. i need my car working for aitp.. its quite a long trip for me!
    #15
  16. superkarl
    Offline

    superkarl MAN OF STEEL

    Joined:
    Mar 28, 2010
    Messages:
    7,553
    Likes Received:
    1,074
    thanks tuffty.
    il remove mine then. id like it to look a little tidier.
    #16
  17. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    essentially that's what i'm running.. and it doesn't work...!
    #17
  18. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    Dude... how many times!!... you do not need another check valve in the servo!!!... the pics above show where the servo check valve is... your problem is clearly elsewhere...

    <tuffty/>
    #18
  19. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    Yes it does...

    Your problem is somewhere else... :)

    <tuffty/>
    #19
  20. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    hmm okay.. i'll take another look and double check everything tomorrow then it's too dark now and i've had enough of it today! checked everything earlier and it all seemed tight. smoke tested it and tightened up where the leaks were...!
    #20
  21. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    You still haven't explained exactly what you have done... what did you remove? what have you blocked up etc? smoke test will only show leaks... if you have joined a pipe wrong somewhere but its still sealed then a smoke test won't help...

    If you have done the catch can/pcv delete as I explained above then then shouldn't be anything that can go wrong...

    What exactly have you done and what and how is stuff connected?

    Pics tomorrow would help too dude... by your own admission you have said you are not that mechanically minded so its easy to have missed something... believe me I have seen some very 'interesting' engine bays in my time from people who believed themselves proficient...

    Its easy to miss something... I have done it myself...

    <tuffty/>
    #21
  22. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    I will take some pics later on to help you understand what i've done but in my mind i've followed the guide! gym now though..! and then more car work.
    #22
  23. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    i wrote that earlier on it that helps'? i'll actually look at the car today and say it as i see it - that explanation was from memory!
    #23
  24. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,731
    Likes Received:
    1,268
    Ah cool... should have spotted that lol....

    Ok... by 'hard pipe brake booster line' I assume you mean all the stuff in the picture I posted above? and not the line that actually goes to the servo? Capped the brake booster line??

    A pictorial explaination of what you changed and the bits removed/fitted would be handy I think as there could be a terminology conflict here lol...

    <tuffty/>
    #24
  25. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    Yeah not the servo line - the hard pipe section of the stuff removed. Get pics inasec
    #25
  26. vrbob
    Offline

    vrbob Thats no Moon, Thats a space station!

    Joined:
    Jun 19, 2007
    Messages:
    2,364
    Likes Received:
    157
    You any closer to solving this Josh?

    When you put piccies up pur some up of your new FMIC too please :)
    #26
  27. jezzy
    Offline

    jezzy Member

    Joined:
    Oct 3, 2011
    Messages:
    760
    Likes Received:
    15
    This bit is wrong mate
    ran piping from catch can to the hocky puck into the t piece which sends one pipe off the bit on the side of the rocker cover and the other bit of the t piece into the lower breather pipe on the oil filter housing etc with the o ring and kept in by a green c clip.

    This is the correct way
    Your hockey puck runs from the catch can to the tip directly not in to the t piece.
    The t piece is for the crank case breather and rocker cover breather to the catch can

    #27
  28. Westy
    Offline

    Westy Double Dark Side! Diesel & 8P

    Joined:
    Dec 2, 2008
    Messages:
    17,295
    Likes Received:
    969
    Should look like this if Venting to the TIP with puck:

    [​IMG]
    #28
  29. Reesy
    Offline

    Reesy Active Member

    Joined:
    Jan 20, 2010
    Messages:
    3,610
    Likes Received:
    133
    Got to be honest, after Westy sorted the massive thread out I didn't think their would be any more problems with this.

    OP, are you posting pics of how it is, or trying tuffty's solution before hand?
    #29
  30. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    Right been out and checked the car I had it piped correctly. I reckon my throttle body has gone. Sorry for no pics I'm on my phone. To test out what was going on I replaced the catch can with the original system as it still runs as I mentioned. And reesy I did have it piped right I just wrote it wrong - I followed te guide exactly it's just it sseems my throttle body has decided to break a
    t the same time causing me to think it was the catch can
    #30
  31. vrbob
    Offline

    vrbob Thats no Moon, Thats a space station!

    Joined:
    Jun 19, 2007
    Messages:
    2,364
    Likes Received:
    157
    Whens the new (secondhand) TB supposed to arrive mate?
    #31
  32. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    ive been at the garage all day again today. tired 3 different throttle bodies on it. hasnt solved it. the fault code is 17967 - throttle body fault in basic settings and when u do the realignment it just clicks and stops and shows error on throttle body alignment status. after trying numerous things they have come to the conclusion that that section needs to be rewired... so thursday it should be fixed.
    #32
  33. vrbob
    Offline

    vrbob Thats no Moon, Thats a space station!

    Joined:
    Jun 19, 2007
    Messages:
    2,364
    Likes Received:
    157
    Fingers crossed mate :) keep us posted
    #33
  34. JtotheD
    Offline

    JtotheD Events Moderator Moderator

    Joined:
    May 13, 2011
    Messages:
    909
    Likes Received:
    24
    cheers Rob. As much as it sucks at least it wasnt anything i've done. im pleased my catch can was right!
    #34

Share This Page