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Clutch Switch over revving - possible quick fix rather than replacement

Discussion in 'A3/S3 Forum (8L Chassis)' started by Boro&Beth, Jun 6, 2009.

  1. Boro&Beth
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    Boro&Beth Member

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    Our S3 was over revving between gear changes which as we all know, the most likely culprit is a faulty Clutch Switch. We bought a new one and it solved the problem.

    However, on taking apart the old Clutch Switch to try and find out what exactly goes wrong with them, we noticed a broken piece of plastic.

    The tiny piece had broken off a section which makes contact with the switch itself BUT and here's the interesting bit....

    The way the switch works is quite clever as its fully self adjusting. Its actually the plunger part of the switch which is the self adjusting part when fully extended (the way it is out of the box).

    The plunger is on a ratchet type mechanism which slides down into the switch and your cars clutch pedal stops it at the correct position for the car. You can hear it ratchet as you push it in by hand.

    However, i think alot of peoples clutch switches may actually NOT be physically broken and instead just need resetting.

    If you remove the switch and fully extend the plunger, then refit it, it may actually stop the over-revving problem without the need to buy a new switch. I know they arent expensive but it would save you the hassle of having to buy one.

    We fitted our new one with the Clutch depressed as releasing the Clutch slides the plunger in, just to ensure we got the correct self-adjustment. Im not sure this made a massive difference but it was just a precaution rather than anything else.

    So, if your car is over revving between gear changes, it might be worth trying to adjust the switch yourself before buying a new one.

    If it works for anyone, let me know if my theory is right or not, it might save some people a bit of money.
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  2. ianysm
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    ianysm Active Member

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    I need to do this but by the time i've got to it to check if its broken or not, i might as well just change it?

    The over revving between gears is annoying now!
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  3. ianysm
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    ianysm Active Member

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    Had a look takes about 2 minutes to remove, none of this unscrewing panels stuff - you can easily get to it from the footwell

    Mine wasn't broken but was pushed in alot. Its the original switch (says 2001 on it) so perhaps something is damaged internally as my adjustments made no difference.

    New one on order!
    #3
  4. Dani_B19
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    Dani_B19 Audi-sports own special child.

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    How do you get to it and remove it?
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  5. Boro&Beth
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    Boro&Beth Member

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    You can see it from the footwell in behind a covering panel. It will be inline with your clutch pedal. If you have small hands you can get to it without taking the panel out, but its alot easier if you remove it.
    #5
  6. Dani_B19
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    Dani_B19 Audi-sports own special child.

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    Then just take it out and inspect it!
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  7. Haglos
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    Haglos jabba mapped

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    where the clutch switch is there is 2 holes 1 above the other which 1 does the switch go in
    #7
  8. sean_s3
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    sean_s3 Member

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    I'm also having the over revving problems when changing gear at high revs. I got a new clutch switch from Audi ( £12.11) but it hasn't fixed the problem.

    The way i fitted it was while having the clutch not pressed in, ease the switch in and allow the pin to adjust itself up against the clutch arm and then screw it into place, and lastly reattach the small lead.

    Does this sound about right ? Its a really annoying problem and im running out of ideas. Ive changed the DV valve to a forge unit, changed the MAF, had the throttle body inspected and two independent audi garages have a look without any joy.

    Any other ideas ?

    Thanks Sean.
    #8
  9. Dani_B19
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    Dani_B19 Audi-sports own special child.

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    Could the clutch be on its way out!
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  10. ianysm
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    ianysm Active Member

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    The top one.


    The one below is just a hole whereas the correct one has little slots for the switch to twist into
    #10
  11. ianysm
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    ianysm Active Member

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    I wouldn't be supprised if i end up with the same problem after replacing.

    That method sounds correct unless anyone else know better? Another method is to depress the clutch while inserting the switch then slowly release clutch but that could go wrong (snap the plunger).

    Mine is the original 2001 switch so i wouldn't be supprised if its internals are damaged.

    If you disconnect the switch does your problem get worse, stay the same or improve?
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  12. ianysm
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    ianysm Active Member

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    Also, i noticed when i had mine out, that the black inner of the switch twists and locks into 2 or 3 different positions. Each one changes the length of the plunger. Anyone know what this is?

    When i re-inserted the unit and twisted it back into the pedal, i noticed this black bit move position again!
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  13. Boro&Beth
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    Boro&Beth Member

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    The black bit needs to turn in order for the contacts to be made inside the switch. Ive heard sometimes the clutch misses the switch completely so might also be worth checking this is you've had a new one and it hasnt solved the problem.
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  14. sean_s3
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    sean_s3 Member

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    No i haven't tried it unplugged yet, but i imagine if the switch is at fault then the problem will still be the same.

    Is the black part on the switch supposed to twist when the plunger is pressed in and then untwist when it is released ? When i press the plunger in the black part doesn't move at all.
    #14
  15. ianysm
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    ianysm Active Member

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    Nope it only twists and locks then the plunger works as normal. I just noticed mine twisted as i inserted it into the pedal and wondered if that was correct.

    Checked again this eve and it appears to be correctly pushed in each time the clutch is moved so it must be a faulty switch inards.
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  16. nath-w
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    nath-w Member

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    i cant work out if my clutch switch is broken. how far does the plunger stick out of the black box as mine is right in all the time. so i am hoping it is my clutch that is broken which is causing the car to over rev between gears.
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  17. Boro&Beth
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    Boro&Beth Member

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    When they come out of the box NEW the plunger will be fully extended. Its self adjusting, so you fit it fully extended, then your clutch with determine how far in it gets plunged. After the initial springiness you notice a ratchet time movement in the plunger. This is the self adjusting mechanism.

    Once the clutch has worked out how far the plunger needs to be IN, it will stay at that point unless further movement is needed inwards again.

    Might be worth depressing your clutch and pulling the plunger fully out, so that the clutch can determine how far in it needs to be again.

    If youve done this and its still over-revving, chances are the internals are broken.
    #17
  18. fran-s3
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    fran-s3 Active Member

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    Thanks for the info! Question: Can you pull the plunger fully out whilst it's still fitted to the car without having to remove it? Easy enough to locate?

    Mine does this ever so slightly by about 200rpms only in the upper rev range so hopefully my plunger just needs re-setting....
    #18
  19. Dani_B19
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    Dani_B19 Audi-sports own special child.

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    Has anyone got a pic of the clutch switch and its location?
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  20. ianysm
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    ianysm Active Member

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    Its located directly above the clutch pedal. If you lie on you back in the drivers footwell and look up, you'll see it. Blue thing that twists into a hole and untwists out!

    Mine still does the over revving thing so i'm out of ideas.

    Someone said they thought it was a function of the remap to prevent turbo stall, bit the tuning copmany that did mine had heard nothing of this!

    Mine goes up more than 200rpm i'm sure. Its VERY annoying!
    #20
  21. Dani_B19
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    Dani_B19 Audi-sports own special child.

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    That thing, i thought that was todo with cruise control?
    #21
  22. fran-s3
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    fran-s3 Active Member

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    Does anyone know if you can reset the plunger whilst it's still installed?
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  23. Boro&Beth
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    Boro&Beth Member

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    I would have thought you could. Its easily accessible from under the footwell. Just stick your hand up there with the clutch depressed and you should be able to pull it out. It usually sticks out about 1cm after being pushed in all the way. Enough to get a grip on.

    Pull it out, then release the clutch and it should be at its optimum point. If its still over revving, then its a new switch needed. But as said, they are cheap and easy to replace, about £12 from Audi and a 5min job.
    #23
  24. ianysm
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    ianysm Active Member

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    No you can't, i tried and there's not enough room to get a good hold on the plunger. It needs a sharp tug. Easier to unclip it then adjust.

    I found it easier to leave the clutch pedal in place and just push the switch back into the hole and let it adjust itself, rather than holding the clutch pedal down
    #24
  25. ianysm
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    ianysm Active Member

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    I think on cars with curise it uses the output for this switch as well. Mine hasn't got cruise though
    #25
  26. rich-hill@hotmail.com
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    rich-hill@hotmail.com Member

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    I have managed to remove my switch, how do i extend the plunger now though?
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