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

S3 Cylinder compression figures?

Discussion in 'A3/S3 Forum (8L Chassis)' started by harrsf, Sep 19, 2012.

  1. harrsf
    Offline

    harrsf New Member

    Joined:
    Feb 18, 2011
    Messages:
    14
    Likes Received:
    0
    [Sep 19, 2012]
    Hi guys, I've been using lots of oil (topping up approx 1.5litres per month) recently. Last night i decided to check the compression of each cylinder, and found i was down a fair bit on 2 cylinders compared to the others. Im not entirely sure what readings to expect but the results i found were as follows,

    170PSI on 2,
    155PSI on 1
    145PSI on 1

    Could anyone please advise me as to what i should be expecting to find? Car is a 2003 BAM engine, REVO stage 1.

    Thanks
    #1
  2. Ads

    Ads

    [Sep 18, 2014]

  3. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,916
    Likes Received:
    1,334
    [Sep 19, 2012]
    Pretty low dude... especially 145psi... typically 180/190psi from memory on a good one... you tried it wet yet? (pour a small amount of oil in the plug hole)

    <tuffty/>
    #2
  4. Andrew@A.L.D
    Online

    Andrew@A.L.D Cylinder Head Master

    Joined:
    Jun 19, 2009
    Messages:
    3,515
    Likes Received:
    361
    [Sep 19, 2012]
    Is it a standard engine?
    #3
  5. harrsf
    Offline

    harrsf New Member

    Joined:
    Feb 18, 2011
    Messages:
    14
    Likes Received:
    0
    [Sep 19, 2012]
    Cheers Tuftty. Yes tried this on the 2 lowest ones and the pressure increased way above this, not sure on figures though, definately above the 170 i found on the other 2 though. Am i right in thinking my problem here lies with the piston rings rather than the valves?
    #4
  6. harrsf
    Offline

    harrsf New Member

    Joined:
    Feb 18, 2011
    Messages:
    14
    Likes Received:
    0
    [Sep 19, 2012]
    The cars been remapped Andrew, Revo stage 1, also have Milltek cat back, FMIC, TIP and aftermarket panel filter.
    #5
  7. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,916
    Likes Received:
    1,334
    [Sep 19, 2012]
    You say the pressures increased when wet tested?

    What were the cyl numbers/pressure in the end?

    <tuffty/>
    #6
  8. harrsf
    Offline

    harrsf New Member

    Joined:
    Feb 18, 2011
    Messages:
    14
    Likes Received:
    0
    [Sep 19, 2012]
    I only wet tested the 2 cylinders closest to the cam belt side, not sure what the numbers of these are. Not entirely sure of the end pressure as i didn't write these figures down but it went upto around 200-210PSI if I remember rightly.
    #7
  9. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,916
    Likes Received:
    1,334
    [Sep 19, 2012]
    Is the car breathing heavy? blue smoke on acceleration? not seen bad valves as such even on high mileage 20vs but have seen worn rings so its plausible that is ts the rings in this case... done a leak down test?

    <tuffty/>
    #8
  10. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,916
    Likes Received:
    1,334
    [Sep 19, 2012]
    so 145psi when dry and 200psi when wet?... thats quite a leap tbh... normally goes up 10/15% iirc

    <tuffty/>
    #9
  11. harrsf
    Offline

    harrsf New Member

    Joined:
    Feb 18, 2011
    Messages:
    14
    Likes Received:
    0
    [Sep 19, 2012]
    Yes it was defiantely a jump of that. The car does seem a little down on power, but no blue smoke, only smoke its given off was after the wet test when burning the oil i'd put in. My next question if you can advise me; how big of a job is it to remove the engine from these cars? Its just that my clutch needs replacing, and i was also thinking of changing the exhaust manifold, downpipe and cat once my other troubles were sorted.... but now thinking of doing it myself with some help from more knowledgable people, and killing a few birds with one stone hopefully?
    #10
  12. Dan s3 audi
    Offline

    Dan s3 audi Member

    Joined:
    Apr 1, 2012
    Messages:
    164
    Likes Received:
    0
    [Sep 19, 2012]
    not too hard, the part i struggled with was getting front bumper off lol as i thought that there must be more holding it on (its simple once you have done it). life is much easier once engine is out to change clutch. your just need red coolant, power steering fluid, if you have air con your lose your gas, and brake fluid.
    #11
  13. harrsf
    Offline

    harrsf New Member

    Joined:
    Feb 18, 2011
    Messages:
    14
    Likes Received:
    0
    [Sep 19, 2012]
    Cheers Dan, i'm a bit of a master at removing and refitting the bumper lol, done it a few times re-attatching popped off intercooler hoses due to inadequate jubilee clips!

    As i say i have zero experience working on engines, let alone removing one but i have friends and family who have, and im full of enthusiasm and want to learn! I work in engineering so im pretty decent with my hands, but i just wanted to make sure removal wasn't something we could start and get stuck into without being properly prepared for.
    #12
  14. Dan s3 audi
    Offline

    Dan s3 audi Member

    Joined:
    Apr 1, 2012
    Messages:
    164
    Likes Received:
    0
    [Sep 19, 2012]
    I am the same, the bottomw end went on my car several months ago. I re-built the whole engine on my own with only a haynes manual and information off the internet. i change everything, crank, mains, bigends, conrods, pistons, rings, oil pump, pump chain, crank oil seals, all the cam belt stuff, re-built head and ground in all the valves. did all this over a period of like three months, never done this before as i am a plumber not a mechanic. and the amazing part is it runs lol done over 3thousand miles in it now and there are no knocks of nothing. It is rewarding doing it yourself, and if you have the time and you want to then why not. I dont think i will ever take the car back to a garage again except for mot and tuneing lol
    #13

Share This Page