Results 1 to 3 of 3

Thread: check valve 2.0 16v 9A

  1. #1

    check valve 2.0 16v 9A

    Hey guys!

    I have a problem with a vacuum leak on my 2.0 9A and when checking the vacuum hoses diagram I noticed that I am missing the check valve all together.

    There is just a hole to where the check valve hose should be.

    Could this be the reason why I have a high idle (1200rpm constantly and with no fluctuations)?

    VW CORRADO 2.0 16v 9A

  2. #2
    ⋆⋆ CF Member ⋆⋆ vw rule's Avatar
    Join Date
    9th February 2013
    Hello there,

    I believe the euro spec or USA spec Corrado / Golf 16v engines had a EGR valve (n.o 28 and was bolted to the back of the inlet manifold, but all UK spec 16v engines as far as I'm aware don't have one, but you can sometimes see the moulded recess where the EGR valve would've gone.

    (N.0 11) In your photo is of the vacuum one way valve, that is fitted into the brake servo vacuum pipe, this reinforced plastic pipe runs from the brake servo to the back right of the inlet manifold.
    The 90 degree rubber hose (n.o 13) fits over a steel nozzle end, sticking out of the inlet manifold.
    If the servo pipe wasn't attached to your inlet manifold, then the engine would not start or it would run really badly and just cut out.

    Sometimes the steel nozzle end sticking out of the inlet manifold, can corrode and shear off leaving a hole, but you would hear a massive suction sound as the cylinders are sucking in air, plus the engine wouldn't run for long it would normally try to cut out.

    Idle control valve can play up causing erratic idle and engine cutting out.

    Brake servo pipe can split or the one way valve can split or fall apart, there should also be vacuum hose/s attached to the one way valve, again these can split or fall off.
    There should be 2 or 3 vacuum hoses attached or if only 2 then there should be a small green plug to seal up the none used 3rd vacuum inlet.

    Inlet manifold gaskets can leak as the manifold is in two half's, the 1.8 16v uses 50mm manifold with matching gaskets, and the 2.0 16v uses 42mm manifold with matching gaskets as standard.

    Throttle body gaskets can leak but it is rare.

    There should be a vacuum hose / pipe attached to the throttle body as well.

    The 45 degree inlet hose attached to front of throttle body can split, plus there should be 2 vacuum hoses attached to the underside of that 45 degree inlet hose.

    The large dome inlet boot on top of the fuel metering head can split also.

    Also if you spray some brake cleaner or carb cleaner or WD40 (remember to be careful of the exhaust manifold) if there is a vacuum leak the engine will change note, it'll normally try and speed up slightly for a few seconds.

    Hope this helps
    Last edited by vw rule; 2 Days Ago at 9:24 PM.
    Had MK2 Scirocco Scarla 1998 to 2002

    Now have Corrado 2.0 16v since 2002 still got it

  3. #3
    Thanks man, you sure know you're way around a corrado!

Similar Threads

  1. Mk4 coolant one way check valve
    By Mk3highline in forum Engine Bay
    Replies: 1
    Last Post: 11th November 2014, 6:06 PM
  2. Flusteds DIY Giro valve (check valve)
    By flusted in forum Engine Bay
    Replies: 10
    Last Post: 1st October 2006, 8:23 PM
  3. which way to fit check valve on g60
    By brian g60 corrado in forum Engine Bay
    Replies: 11
    Last Post: 25th December 2003, 12:50 PM
  4. check, one way valve
    By olly elworthy in forum Engine Bay
    Replies: 7
    Last Post: 9th October 2003, 10:22 PM
  5. check valve
    By brian g60 corrado in forum Engine Bay
    Replies: 4
    Last Post: 28th September 2003, 4:46 PM


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
About us
We are the world's largest community for VW's Super Coupé! Be it 8v, 16v, G60 or VR6 (or maybe something else!), everybody's welcome! If this is your first visit, be sure to click register and fill out your details before you can post.
Help us
This site is run on donations.
Please help keep the forum alive!
Follow us
advertising & sponsorship
Are you a company looking for advertising that could benefits our users? For site & forum sponsorship, please see our dedicated microsite here.