Convenience feature glitch?

[Jake@JHM]

So @Jake@JHM, he is still pretty adamant that is the clutch assembly somehow. He wants me to come down so i can see what they are talking about... Supposedly, they are now able to duplicate the issue cold. He says if he pushes the clutch in super hard, it will still start.... Does that mean anything different to you?

Clutch switch?

[jimrobbington]

Clutch switch?

Lol, i want to kill someone. I'll update when i get home.

[Brother Owl]

Love the info in this thread but slowly getting more concerned. Everytime I've started my car recently I've had to push the clutch HARD... new clutch isn't in the budget anytime soon

[jimrobbington]

Love the info in this thread but slowly getting more concerned. Everytime I've started my car recently I've had to push the clutch HARD... new clutch isn't in the budget anytime soon

Tell me about it! OMFG it has been a stressful day. I get so worked up about my car, when i don't know what's wrong, how to fix it, or most importantly, how much it will cost. Only thing more stressful is women!

So, i left work a little early and headed to the dealer to talk and see what they are seeing. The problem is no longer intermittent. It's 100% of the time it seems. BUT, it can be started by pressing the clutch pedal harder than normal. Seems like this can be done 100% of the time. So dealer won't look at it further without blaming the JHM parts.

So i get in, press the clutch normal til it stops, doesn't start. Force the clutch just 1-2 mm past the "normal" stopping point, and it starts up like nothing is wrong.

Dealer thinks the JHM pressure plate and/or flywheel is the culprit.

I think the dealer cut a corner in their previous work and/or didn't do something right.

Either way, I'm fucked with the dealer and I took my car. Luckily no charge for today's debacle.

So here's the funny thing. Now that i know how to start it, it's not a big deal. I just have to press the clutch sorta hard. For like a millimeter. Doesn't bother me, if that's how it is, so be it. I just want to feel confident it will always start, also that it's not doing damage leaving it like this. I would also like to know why, but that's the last of my worries. Like i said, it's just different enough that i never accidentally got the car to start, but it's not hard to start the car now that i know.

I drove home 30-40 minutes, the clutch/fw still feel amazing. Pedal feel is light and spot on. Still feel absolutely nothing wrong with anything the rest of the time.

[infinkc]

So @Jake@JHM, he is still pretty adamant that is the clutch assembly somehow. He wants me to come down so i can see what they are talking about... Supposedly, they are now able to duplicate the issue cold. He says if he pushes the clutch in super hard, it will still start.... Does that mean anything different to you?

Im curious also Jake, as you know i am running the stage 4 setup now. I had the same problem before when I brought my car into the shop for the clutch/fly. I had them change out the clutch fork also as i heard this can be an issue. I have put about 3k on the setup, it has started perfectly up until last week. I have to press super hard down again!

What could it be? Seems like the exact same issue as Jim's and we both have changed our clutch and the problem went away, now its back.

[Jake@JHM]

Im curious also Jake, as you know i am running the stage 4 setup now. I had the same problem before when I brought my car into the shop for the clutch/fly. I had them change out the clutch fork also as i heard this can be an issue. I have put about 3k on the setup, it has started perfectly up until last week. I have to press super hard down again!

What could it be? Seems like the exact same issue as Jim's and we both have changed our clutch and the problem went away, now its back.

That's a good question. We would need to have the car here and spend some time diagnosing to figure out the actual cause of the issue and what a permanent fix would be.

[jimrobbington]

Im curious also Jake, as you know i am running the stage 4 setup now. I had the same problem before when I brought my car into the shop for the clutch/fly. I had them change out the clutch fork also as i heard this can be an issue. I have put about 3k on the setup, it has started perfectly up until last week. I have to press super hard down again!

What could it be? Seems like the exact same issue as Jim's and we both have changed our clutch and the problem went away, now its back.

Yes, please go visit Jake! We are thinking/hoping it has something to do with the master cylinder.

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[footbllpro30]

I'm having the same issue with my 2013 S5 with 23K miles on it. Have to press very hard on the clutch pedal for the car to start. This is ridiculous, such an expensive car. I am taking it into the dealership tomorrow, hopefully they cover whatever the issue is under warranty.

[jimrobbington]

I'm having the same issue with my 2013 S5 with 23K miles on it. Have to press very hard on the clutch pedal for the car to start. This is ridiculous, such an expensive car. I am taking it into the dealership tomorrow, hopefully they cover whatever the issue is under warranty.

Lol, don't bet on it, but good luck!

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[S4'ed]

So, here is a fix idea:
From pictures of the clutch master cylinder, it looks like is has a rubber gasket (grey ring on black cylinder body) between it and the firewall (on the engine compartment side). If you remove the gasket, or use a thinner one, then the master cylinder internal piston will be moved a little further into the bore when the clutch pedal is fully depressed, which might be the extra 3 or 5mm needed to get the start-switch to trip.

Maybe remove the gasket and use some RTV to seal against water entry....if it doesn't work it is easily reversible.

https://www.ecstuning.com/Audi-B8_S4...lic/ES2832727/

[infinkc]

Info on the clutch master cylinder switches/sensors:
The clutch master cylinder has three switches integrated into it.

there is the F36 Clutch Pedal Switch that is used for cruise control
there is the F194 Clutch pedal switch that triggers the "Press Pedal to start" part of the car
there is the G476 Clutch position sensor.

You can use a Vagcom to measure the blocks of both the switches. its block 265(F194), starter control clutch switch and block 266(G476) starter control, interlock switch (may be a few numbers different depending on what version vag you have loaded)

The last bit will change to a 1 when active.

Both need to be "1" for the car to start.

If you felt like bypassing the switch you can simply ground out the wire in the ecu box that gets triggered. blue gray is the F194 and green/gray is the G476.

This was info i had posted on a previous thread that i found doing some research on the issue. I am wondering what the G476 sensor is actually triggered with, is it fluid pressure, simple microswitch? I wonder what its function is, as there is a switch already for the clutch pedal. It says its a position sensor, so im guessing it has a pressure sensor. anyone know? Someone said they accidentally removed theirs, so possibly a hall sensor?

Im thinking on swapping out my master, slave and line, just to fix the issue. I thought about doing one at a time, but i dont have the time for that now.

[S4'ed]

I bet the "position sensor" is not a pressure sensor, it is probably a hall "switch", like the other two. I think the master cylinder piston has a magnet in it, and as it moves it activates one of the three hall switches, which are mounted in the wall of the cylinder bore, along the stroke path of the piston.

My guess is :
- Switch#1 is "normally-closed" at the fully-released pedal position, which is used to disengage the cruise when you depress the pedal. T6g/2 or /3
- Switch #2 "clutch position sensor" at the approximate clutch engagement point, somewhere in the middle of the pedal travel. This is used for the throttle blip during a shift, and the auto parking brake release. T6g/5
- Switch #3 is the starter interlock, at the fully depressed pedal position. T6g/2 or /3

[jimrobbington]

Props to all whom have contributed to this strange thread! However, the plot has a strange new twist. ..

So I'm at ~525 miles on this clutch. Pretty safe to say that break in period is over. So it's snowing just enough the streets are moist and cold. I don't launch, but romp on 1st gear out of a hard right turn onto a 3 lane highway. I get the rear looser than I intended and let off the gas, once straight again, I step on it, hit 7000 remember limiter super fast, and shift into 2nd gear.

All of a sudden, the clutch pedal comes out farther than ever, and has a weird pressure behind it. I push it back in and it sticks in for a second, and then slowly it comes out with vacuum behind it, similar to the original symptoms that led me to the whole clutch upgrade in the first place. And then......everything went completely normal. Drove around, clutch seems to engage slightly smoother than before. I stopped, and started the car. The car now starts completely normal, without any additional pressure needed. So wtf? Any idea? Am I safe now, or what?

[jimrobbington]

Lol, so that was short lived. Went in to eat lunch, came back out, have to push the clutch harder again to start it. So freaking weird.

[Jake@JHM]

Your master is probably done

[S4inBC]

Can you bleed the clutch line/slave on these carclus? Sounds kind of like you've got a little bubble wandering around in the line and messing with you.

[dizzlesizzle]

I've been dealing with this going on 2 years now. Doesn't happen all the time, maybe twice a week but maybe since I'm used to it, I might be pushing down harder all the time on the clutch and when I forget is when it happens. Doesn't matter if its a cold start or not, push the clutch down normally to start...nothing...radio comes on, get a few clicks from pushing the key in and message that says push clutch to start car. take the key out, drop a couple F bombs, push down hard on the peddle and starts up no problem. still riding on factory clutch with 59K on the car.

I will keep you updated though, because the car is in the shop right now...guess it needs a new transmission, was making a weird noise, posted about it here http://www.audizine.com/forum/showth...smission+noise

Since the transmission is already going to be out, i might as well get a new clutch since they wont be charging me any labor for it. I will let you know how I make out with the starts after the new clutch. Should have it back this week.

On a side note, the shop wanted to know if i wanted to do the flywheel along with the clutch. I said no since it was another $1000 if not more. Can't see needing a new flywheel with only 59K on the car. I've replaced many clutches in other cars and never did the flywheel and went over 200k miles on them. thoughts?

[jimrobbington]

I would think you should be fine as long as it gets resurfaced.

[E.Anderson]

Mine is currently at audi for the clutch for the same ignition switch issue. They're replacing the clutch master cylinder

[jimrobbington]

Mine is currently at audi for the clutch for the same ignition switch issue. They're replacing the clutch master cylinder

Wish my dealer was smart...

[Ze_Nardo6]

what is part number for clutch master cylinder?

[S4'ed]

8k1721401h

[Ze_Nardo6]

8k1721401h

You're the man!

[jimrobbington]

So quick update. ..

Last night, the clutch needed to be pressed harder to get it started. But I got it started. So today, I try and start it, same thing. Then I go to start it one more time, and something popped in the clutch pedal, like it punched through something. Now the pedal can travel to the floor, but it still returns. The good news is that now I can easily push it in far enough to start it with ease. But now I'm even more afraid to drive it. I did drive around the block, and shifting still feels normal. It is just strange how far the pedal can travel now. I'm parking it to make sure there are no leaks or anything. Just waiting till tomorrow to talk with my shop. ..

[Jake@JHM]

Hmm.. sounds like a slave issue or something

[Ze_Nardo6]

I had the same issue as many others in this thread. The "press clutch pedal to start car" light would come on and I could barely get my car started. I opted to replace the master cylinder and the problem is currently resolved.

[infinkc]

I had the same issue as many others in this thread. The "press clutch pedal to start car" light would come on and I could barely get my car started. I opted to replace the master cylinder and the problem is currently resolved.

Your issue is a tad different, cause like the ops, my car its not the "press clutch pedal" sensor. I dont get that message, for that message it is definitely the master. Our case the message doesnt show, and you still have to press the pedal all the way down.

[jimrobbington]

So, bit of an update. Due to the holidays, haven't been able to take the car into the shop yet. Out of necessity, I have been driving the car still. Since "the pop" the clutch has felt completely fine. Today, Scott, one of the owning partners, and shop manager of 3zero3 Motorsports, was kind enough to take time out of his new year holiday to meet up with me and check out the car.

In his opinion, he believes that the clutch and everything is completely fine at this point. His diagnosis makes sense in my mind and takes some stress off my shoulders. He believes that something wasn't seated properly during installation. I did initially note that the new clutch had a much shorter throw than stock. The "pop" I felt was actually this part snapping into place fully, and allowed my pedal full travel as it should have had in the first place. He played with the clutch, drove it around the block, commented how amazing my exhaust sounded, and really thinks that everything is working as it should at this point. I am relieved, but what a strange process this has been.

[okioki]

Hi all, Just read the entire thread looking for a solution. I have the same symptons as described. This morning I changed the Clutch Master Cylinder however the problem still persists. I have to press the clutch pedal really hard to get the car started. I am thinking of changing the Clutch slave cylinder this week to see if that is the culrpit. What do you guys think?

I have noticed that there are various revitions of the Clutch Master Cylinder - Audi Part 8k1721401 ( From A to H). My original part was letter A and Audi is now selling upto revition H. The one I installed this morning is letter D. I wonder if this has anything to do and if there are any improvements with solutions?

Any ideas would be welcomed,
Thanks,
JuanCarlos
Madrid, Spain

[rx7ven]

Hi all, Just read the entire thread looking for a solution. I have the same symptons as described. This morning I changed the Clutch Master Cylinder however the problem still persists. I have to press the clutch pedal really hard to get the car started. I am thinking of changing the Clutch slave cylinder this week to see if that is the culrpit. What do you guys think?

I have noticed that there are various revitions of the Clutch Master Cylinder - Audi Part 8k1721401 ( From A to H). My original part was letter A and Audi is now selling upto revition H. The one I installed this morning is letter D. I wonder if this has anything to do and if there are any improvements with solutions?

Any ideas would be welcomed,
Thanks,
JuanCarlos
Madrid, Spain

hey okioki,

what was the result after replacing the clutch slave cylinder?

[jimrobbington]

hey okioki,

what was the result after replacing the clutch slave cylinder?

Fyi, I just replaced slave and the push clutch to start issue returned. I had "resolved" the problem by breaking the slave, allowing full travel of pedal again. Slave was leaking, it got replaced, now can't start car again ;(

[LittleBlueBox]

Fyi, I just replaced slave and the push clutch to start issue returned. I had "resolved" the problem by breaking the slave, allowing full travel of pedal again. Slave was leaking, it got replaced, now can't start car again ;(

Jimrobbington, how's your car doing now?

[jimrobbington]

Jimrobbington, how's your car doing now?

Everything has been fixed for many many months at this point with the electronic 3zero3 mod.

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