6MT clutch pedal action

M_Swee · 07-01-2019, 02:43 PM

Current owner of a '17 M3 with a 6MT, with the comp package although that probably doesn't make a difference with my question.

I have about 16K miles now, have been driving a manual for 10+ years so I'd like to believe that I'm not overly wearing down the transmission due to inexperience.

Every once in awhile, the pedal travel will feel "spring-y", where it's almost like there's a squeaky spring or coil that is slightly pushing back or introducing vibration. But after that one-time in/out of the pedal, it goes back to being normal. Hard to describe. Like if you were just normally walking down the street, and then for just 1 step you landed on a spring.

I don't know enough mechanically, to diagnose or identify the root cause. Maybe the clutch cylinder (from a rudimentary google search), or an "assist spring"?

An image I found online of the pedal set-up, maybe there is some issue with part #21.

Any help is greatly appreciated, before I go to see the service center. I imagine they won't be able to replicate this because it happens to me maybe once every 1-2 months.

Paisano · 07-06-2019, 08:44 AM

This has been an on-going issue for me, especially during spirited drives when I shift quickly between gears.

I brought this to the attention of my Service Centre and it's normal. Apparently most modern manual cars have a clutch restrictor installed and that slows the return of the clutch pedal to it's neutral position between shifts. This really bothered me and I put in a 'clutch stop' so the pedal does not have to travel all the way to the floor. The actual engagement point is about 65-70% of the clutch travel.

Short-end of it, it's normal.

Kilabyte · 07-13-2019, 10:25 PM

I put a BMS clutch stop in as well, issue is that here and there it goes into 1st a bit "rough", I think that I will remove one of the shims in the stop so I don't ruin the synchros.

LIF83 · 07-14-2019, 04:02 PM

This weekend I have felt this spring-y clutch pedal as well. Only really in first gear in the beginning of my drive. Then seems to go away.. very weird after 8k miles. Assuming it’s normal, the forum is great !

Paisano · 07-29-2019, 06:50 PM

Quote:

Originally Posted by Kilabyte

I put a BMS clutch stop in as well, issue is that here and there it goes into 1st a bit "rough", I think that I will remove one of the shims in the stop so I don't ruin the synchros.

Personally I decided to only use 2 shims for this exact reason.

However, the difference was noticeable - especially during quicker shifts.

Tommy L Garage · 08-08-2019, 05:29 AM

Solution:
1. BMS clutch stop
2. Brake fluid flush

You’ll be as good as new

chmura · 08-09-2019, 11:26 AM

There is a hidden clutch delay valve inside the slave cylinder in the S55 and N55 manuals. They share the same transmission.

I have a really annoying WOT 1-2 shift delay and it might be due to the Clutch Delay Valve.

Here is a good DIY to remove it. M3/M4 and M2 manuals have the exact same transmission.

Lots of wrong information on the forum being posted about the M4 not having a CDV, it does not have a conventional external CDV but instead its integrated into the slave cylinder which needs modification.

Worth looking into.

https://f87.bimmerpost.com/forums/sh...ch+delay+valve

Mendoteach · 08-10-2019, 12:39 PM

I've had a '17 ZCP 6 speed for a few months...is the clutch delay valve causing what feels like a tenth of a second delay of the pressure plate grabbing when I downshift? I completely release the clutch, then the clutch grabs some time shortly after and the revs rise. Annoying.

Paisano · 08-15-2019, 08:09 AM

Quote:

Originally Posted by Mendoteach

I've had a '17 ZCP 6 speed for a few months...is the clutch delay valve causing what feels like a tenth of a second delay of the pressure plate grabbing when I downshift? I completely release the clutch, then the clutch grabs some time shortly after and the revs rise. Annoying.

That would be the delay valve 'helping you' re engage the clutch.

Mendoteach · 08-17-2019, 12:02 AM

Quote:

Originally Posted by Paisano

That would be the delay valve 'helping you' re engage the clutch.

Paisano, thanks for the input. I had a feeling that's what it was and one one of the reasons the clutch engagement is vague, spongy and irregular in the engagement point. That thing is coming out.

Paisano · 08-17-2019, 01:39 AM

Quote:

Originally Posted by Mendoteach

Paisano, thanks for the input. I had a feeling that's what it was and one one of the reasons the clutch engagement is vague, spongy and irregular in the engagement point. That thing is coming out.

No problem. However, I looked into removing the clutch restrictor and it's quite an undertaking. If you are planning on removing it, please record/write-up the process - from the diagrams it looks intensive.

Kilabyte · 08-20-2019, 12:14 AM

Quote:

Originally Posted by chmura

There is a hidden clutch delay valve inside the slave cylinder in the S55 and N55 manuals. They share the same transmission.

I have a really annoying WOT 1-2 shift delay and it might be due to the Clutch Delay Valve.

Here is a good DIY to remove it. M3/M4 and M2 manuals have the exact same transmission.

Lots of wrong information on the forum being posted about the M4 not having a CDV, it does not have a conventional external CDV but instead its integrated into the slave cylinder which needs modification.

Worth looking into.

https://f87.bimmerpost.com/forums/sh...ch+delay+valve

Holy crap, I completely forgot about the CDV, I did the delete on my last car and it was like night and day, no wonder I missed a shift or two when trying to shift as fast as I'm used to after getting this car, as of now this is my next must do thing, no time this weekend

chmura · 08-20-2019, 09:20 AM

Quote:

Originally Posted by Kilabyte

Holy crap, I completely forgot about the CDV, I did the delete on my last car and it was like night and day, no wonder I missed a shift or two when trying to shift as fast as I'm used to after getting this car, as of now this is my next must do thing, no time this weekend

Once you do it please share your impressions!

GTABurnout · 03-31-2021, 02:09 PM

Any more updates on this.

Considering something similar.

irunalot · 03-31-2021, 02:20 PM

Quote:

Originally Posted by GTABurnout

Any more updates on this.

Considering something similar.

The clutch delay valve? Remove it stat! I could never get a smooth 1-2 shift due to the lag in clutch engagement. It's like a different car now much improved.

N44RP · 04-26-2021, 09:23 PM

Quote:

Originally Posted by irunalot

The clutch delay valve? Remove it stat! I could never get a smooth 1-2 shift due to the lag in clutch engagement. It's like a different car now much improved.

How did you bleed the clutch? Seems like it’s not intuitive.

irunalot · 04-27-2021, 12:33 AM

Quote:

Originally Posted by N44RP

Quote:

Originally Posted by irunalot

The clutch delay valve? Remove it stat! I could never get a smooth 1-2 shift due to the lag in clutch engagement. It's like a different car now much improved.

How did you bleed the clutch? Seems like it’s not intuitive.

I had a ship do it for me. I'll ask them how the did it.

Fat Goose · 04-28-2021, 01:21 AM

I reverse bleed it with a syringe

Djdnav · 04-30-2021, 11:41 PM

Quote:

Originally Posted by N44RP

How did you bleed the clutch? Seems like it’s not intuitive.

Quote:

Originally Posted by irunalot

I had a ship do it for me. I'll ask them how the did it.

it's done from the bleed valve on the clutch slave cylinder.

Fat Goose · 08-05-2021, 10:55 AM

Quick question on the subject, does a brake fluid change also bleed and change the clutch brake line (I know they share the same brake fluid reservoir)? Or does it require to bleed the clutch line like you do for each wheel brake line?

Have one last scheduled maintenance brake fluid change at the dealer before the DIY changes, and wondering if I need to specifically request the clutch change with the brake fluid change.

07-01-2019, 02:43 PM	#1
M_Swee Private 28 Rep 65 Posts Drives: 2017 YMB M3 Competition, MT Join Date: Feb 2017 Location: Washington, DC iTrader: (0)	6MT clutch pedal action Current owner of a '17 M3 with a 6MT, with the comp package although that probably doesn't make a difference with my question. I have about 16K miles now, have been driving a manual for 10+ years so I'd like to believe that I'm not overly wearing down the transmission due to inexperience. Every once in awhile, the pedal travel will feel "spring-y", where it's almost like there's a squeaky spring or coil that is slightly pushing back or introducing vibration. But after that one-time in/out of the pedal, it goes back to being normal. Hard to describe. Like if you were just normally walking down the street, and then for just 1 step you landed on a spring. I don't know enough mechanically, to diagnose or identify the root cause. Maybe the clutch cylinder (from a rudimentary google search), or an "assist spring"? An image I found online of the pedal set-up, maybe there is some issue with part #21. Any help is greatly appreciated, before I go to see the service center. I imagine they won't be able to replicate this because it happens to me maybe once every 1-2 months. __________________ 2017 M3 Competition, MT
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07-13-2019, 10:25 PM	#3
Kilabyte I'm Batman! 3948 Rep 1,477 Posts Drives: Mineral White M3 6MT Join Date: Jun 2019 Location: Massachusetts iTrader: (1)	I put a BMS clutch stop in as well, issue is that here and there it goes into 1st a bit "rough", I think that I will remove one of the shims in the stop so I don't ruin the synchros. Last edited by Kilabyte; 07-14-2019 at 11:02 AM..
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07-14-2019, 04:02 PM	#4
LIF83 Private First Class 13 Rep 101 Posts Drives: F80 Join Date: May 2019 Location: Centerport NY iTrader: (0)	This weekend I have felt this spring-y clutch pedal as well. Only really in first gear in the beginning of my drive. Then seems to go away.. very weird after 8k miles. Assuming it’s normal, the forum is great !
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08-08-2019, 05:29 AM	#6
Tommy L Garage Colonel 2516 Rep 2,079 Posts Drives: 2017 YMB M3 6MT CP EP VP Join Date: Dec 2008 Location: Woodbridge, NJ iTrader: (2)	Solution: 1. BMS clutch stop 2. Brake fluid flush You’ll be as good as new
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08-09-2019, 11:26 AM	#7
chmura Colonel 1558 Rep 2,505 Posts Drives: 2019 M2 Competition Join Date: Aug 2009 Location: Orange County, California iTrader: (1)	There is a hidden clutch delay valve inside the slave cylinder in the S55 and N55 manuals. They share the same transmission. I have a really annoying WOT 1-2 shift delay and it might be due to the Clutch Delay Valve. Here is a good DIY to remove it. M3/M4 and M2 manuals have the exact same transmission. Lots of wrong information on the forum being posted about the M4 not having a CDV, it does not have a conventional external CDV but instead its integrated into the slave cylinder which needs modification. Worth looking into. https://f87.bimmerpost.com/forums/sh...ch+delay+valve __________________ 2019 M2 Competition- October 2, 2018 ED 2011 BMW M3 Sedan Alpine White Picked up via ED 9/27/2011 & Redelivered 11/23/2011 SOLD
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07-06-2019, 08:44 AM	#2
Paisano Private 21 Rep 80 Posts Drives: M4 Comp Join Date: Feb 2017 Location: Canada iTrader: (0)	This has been an on-going issue for me, especially during spirited drives when I shift quickly between gears. I brought this to the attention of my Service Centre and it's normal. Apparently most modern manual cars have a clutch restrictor installed and that slows the return of the clutch pedal to it's neutral position between shifts. This really bothered me and I put in a 'clutch stop' so the pedal does not have to travel all the way to the floor. The actual engagement point is about 65-70% of the clutch travel. Short-end of it, it's normal.
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08-10-2019, 12:39 PM	#8
Mendoteach Enlisted Member 20 Rep 38 Posts Drives: 2004 330i ZHP, 2017 F80 ZCP 6M Join Date: Jan 2019 Location: Mendocino County iTrader: (0)	clutch delay when downshifting I've had a '17 ZCP 6 speed for a few months...is the clutch delay valve causing what feels like a tenth of a second delay of the pressure plate grabbing when I downshift? I completely release the clutch, then the clutch grabs some time shortly after and the revs rise. Annoying. Last edited by Mendoteach; 08-12-2019 at 10:07 AM..
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03-31-2021, 02:09 PM	#14
GTABurnout Private First Class 80 Rep 104 Posts Drives: M4 Manual Join Date: Dec 2019 Location: Tucson iTrader: (0)	Any more updates on this. Considering something similar.
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04-28-2021, 01:21 AM	#18
Fat Goose Lieutenant 246 Rep 513 Posts Drives: '18 F83 ZCP 6MT \| F/A-18E Join Date: Dec 2012 Location: Virginia Beach, VA iTrader: (1)	I reverse bleed it with a syringe
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08-05-2021, 10:55 AM	#20
Fat Goose Lieutenant 246 Rep 513 Posts Drives: '18 F83 ZCP 6MT \| F/A-18E Join Date: Dec 2012 Location: Virginia Beach, VA iTrader: (1)	Quick question on the subject, does a brake fluid change also bleed and change the clutch brake line (I know they share the same brake fluid reservoir)? Or does it require to bleed the clutch line like you do for each wheel brake line? Have one last scheduled maintenance brake fluid change at the dealer before the DIY changes, and wondering if I need to specifically request the clutch change with the brake fluid change.
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