carwyn rees s3
Registered User
hi,every time i put the clutch in to change gear the revs keep going up approx 1500 rpm and then drop,ive recently fitted a new geniune clutch switch, anyone any ideas? thanks
reving problem
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Dane
Had an 8L S3, a B5 RS4 now I have a B8 S4
I'm almost certain this is a problem with the clutch switch, more precisely the fine tuning of the switch.
My s3 was over revving by about 800rpm when dipping the clutch - I changed the clutch switch no difference. I then thought what the hell, they're only £12 ill try another one - No change!
As I have 2 switches I reckon it'll be a good idea to take one apart and try and figure out what needs to happen. It's a fairly simple mechanism its just a bit fiddily, essentially the black plunger that moves in and out as the pedal moves was not connected to the parts that actually move inside the casing and do the actual switching. After about an hour and a half of trial an error I managed to get the plunger to make contact with the switching mechanism in such a way that reduces the over revving to circa 100 revs when dipping the clutch, not completely solving it but making it sooooo much better.
I'm now getting annoyed with it over revving by 100, it just ruins the experience when changing gear whilst giving it the beans, but I really dont want to take it apart and make it worse lol! It happens on mine consistantly, there was a chap, I can't remember who, who found a leak in a boost/vaccuum pipe and once it was repaired the car stopped over revving.
The switches are different between facelift and prefacelift it would appear, Welly's clutch switch on his prefacelift is black whilst my facelift AMK clutch switch is blue, I'm not sure if this is worth exploring but if I find the time I might.
Edit: More over - Interestingly when my speedo and fuel sensor were not working the car wasn't over revving
My s3 was over revving by about 800rpm when dipping the clutch - I changed the clutch switch no difference. I then thought what the hell, they're only £12 ill try another one - No change!
As I have 2 switches I reckon it'll be a good idea to take one apart and try and figure out what needs to happen. It's a fairly simple mechanism its just a bit fiddily, essentially the black plunger that moves in and out as the pedal moves was not connected to the parts that actually move inside the casing and do the actual switching. After about an hour and a half of trial an error I managed to get the plunger to make contact with the switching mechanism in such a way that reduces the over revving to circa 100 revs when dipping the clutch, not completely solving it but making it sooooo much better.
I'm now getting annoyed with it over revving by 100, it just ruins the experience when changing gear whilst giving it the beans, but I really dont want to take it apart and make it worse lol! It happens on mine consistantly, there was a chap, I can't remember who, who found a leak in a boost/vaccuum pipe and once it was repaired the car stopped over revving.
The switches are different between facelift and prefacelift it would appear, Welly's clutch switch on his prefacelift is black whilst my facelift AMK clutch switch is blue, I'm not sure if this is worth exploring but if I find the time I might.
Edit: More over - Interestingly when my speedo and fuel sensor were not working the car wasn't over revving
Dane
Had an 8L S3, a B5 RS4 now I have a B8 S4
No worries mate,
It is fairly fiddily but it isn't rocket science, when you open it up you'll see the plunger has a set of teeth that correspond to a set of teeth on the switching mechanism by changing this allignment you can change the distance that the plunger travels.
The way I think it works is:
The plunger should move the switching mechanism backward and forward as you press and depress the clutch pedal.
The switching mech. has 2 metal contacts that slide along 2 corresponding strips of metal on the bottom of the plastic housing.
1 of these strips has a section of metal removed.
When the plunger moves the switching mech through this section the incomplete circuit tells the car the clutch is down and the car does the rest.
This doesn't fully make sense as, why would this change the amount of over revving that occours? so I imagine that the above isn't the exact process but it's the best I could do and its almost worked lol!
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Good findings....Mine does it every now and again, so more annoying, plus makes you look like a **** on roundabouts etc...lol
Dane
Had an 8L S3, a B5 RS4 now I have a B8 S4
It's not too bad at a 100 Revs but it was a major embarassment when the revs jumped by 800.
I really wish I could fix it and get rid of the over revving altogether but I think there must be more to it. Perhaps it could be a combination of things, how does the engine sense the position of the acelerator pedal?
I really wish I could fix it and get rid of the over revving altogether but I think there must be more to it. Perhaps it could be a combination of things, how does the engine sense the position of the acelerator pedal?
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Dane
Had an 8L S3, a B5 RS4 now I have a B8 S4
This is where it gets all speculative, I think I might have a bash at cleaning my throttle body, it probably needs doing anyway and see what results that gives.
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Well it has to be something to do with the electronic accelerator, is this something that can be changed? without changing the whole pedel?
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I would have thought the pedal is not at fault or you would have jerky acceleration....more like the TB but i have had a brand new one of them fitted too....so as said no definative answer....
Dane
Had an 8L S3, a B5 RS4 now I have a B8 S4
I think before cleaning the TB it would be useful to take the clutch switch from an s3 that isn't over revving and see if that cures it, so as a variable can be ruled out.
carwyn rees s3
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carwyn rees s3
Registered User
Dane
Had an 8L S3, a B5 RS4 now I have a B8 S4
carwyn rees s3
Registered User
carwyn rees s3
Registered User
Smokey_clark
12th Gear
My car has just had a revo remap at Audi driver International and as it was being mapped the guy said i need a new clutch position sensor (No over reving before the map), fair enough replaced that which made the over reving less extreme (was over reving about 1000 revs before). Now it still goes up about 200 revs on random occasions and i wonder if its down to the fact that my clutch is nearing the end of its life so pedal travel is quite a lot and maybe the sensor isn't working quick enough?
Last edited:
it is down to the map i think....
its known as "hang time" isnt it? in between gear changes, its where the engine holds the revs reached in one gear as you change to the next gear.
the chip i have in my bmw atm has more hang time programmed into it.
at first i found it quite annoying tbh, fitted the standard chip back in and complained to the guy on e30zone about it. he said yeah it has more hang time, but just change the way you drive it and it all seems to make sence..... come off the accelarator half a second before you press the clutch down to change gear.
its known as "hang time" isnt it? in between gear changes, its where the engine holds the revs reached in one gear as you change to the next gear.
the chip i have in my bmw atm has more hang time programmed into it.
at first i found it quite annoying tbh, fitted the standard chip back in and complained to the guy on e30zone about it. he said yeah it has more hang time, but just change the way you drive it and it all seems to make sence..... come off the accelarator half a second before you press the clutch down to change gear.
is anyone's cruise control not working due to this? My clutch pedal broke yesterday and I replaced it all properly but then I went for a test drive and its started to over rev as well as the cruise control not working so i'm not sure if its due to a faulty clutch switch now as well
Dane
Had an 8L S3, a B5 RS4 now I have a B8 S4
So whilst changing the clutch switch sees improvements it does not remove the problem, which makes me think there is another problem. So does anyone think the remaining over revving (100 rpm or so) could be an anti stalling measure, perhaps because another sensor is malfunctioning and giving an incorrect reading. I mention it only as Welly kindly scanned by car the other day as it wasn't boosting properly and the engine speed sensor was showing a fault. My thoughts being that because the car has no idea where the crank is it throws a couple of hundred revs in on a gear change for good measure. I may be talking rubbish, but just an idea.
