E46M3 Clutch Issue Diagnostic/Help

[Jkloc23]

E46M3 Clutch Issue Diagnostic/Help

Backstory:
clutch was replaced within the last 5k miles according to previous owner with a lightweight single mass flywheel (car purchased 11/20) clutch has felt strong with typical single mass flywheel clutch chatter without the clutch pushed in.

While backing out of my driveway I came to a complete stop and had the clutch depressed and foot on the brake while I put an address in my GPS.

With the clutch pedal depressed the clutch slipped/gave out and the car stalled out. There is slight pressure and the pedal returns, however, it is not building any noticeable pressure. With car off I can put it in gear and start it (wheels off the ground) and it stays in gear. With car in neutral can start the vehicle but can’t put it in gear due to the resistance.

I checked fluid and it was slightly low, maybe 2-3oz max (probably less/still above the low line) refilled to full (have not bled yet)

Checked the slave cylinder and there is no external leak and not feeling/seeing any leak from the master cylinder.

When the clutch is pushed in there is a noticeable vibration fee/sound as if the slave is overextending which makes me think it’s not a hydraulic issue and potentially an issue with the clutch assembly

Anyone have any thought/any chance it is an hydraulic issue (I will be bleeding the slave shortly) thinking it may be the throw out bearing but looking for some insight before I drop the transmission and inspect internally.

[heinzboehmer]

Start with bleeding and making sure the hydraulics are all working properly. If that's all good then yeah next step would be to drop the transmission.

If I had to guess (and assuming all hydraulics are good), I would say that there's been some sort of failure with your pivot fork/pin that's not allowing the clutch to fully disengage.

Edit: Oh and if you have a clutch stop, make sure it hasn't moved and is allowing for the clutch pedal to actuate fully.

[jbfrancis3]

I had to spend extra effort to get all air of out the slave cylinder after a clutch line upgrade. Unbolt the slave from the housing, hold in your hand and tilt up so the bleed nipple is up, loosen the bleed and gently tap the housing with a hammer, then have an assistant depress and hold the clutch, you tighten the nipple, then clutch out. Repeat a few times. Ensure the assistant doesn't depress the clutch when the nipple is closed. You don't know if or why air was let into the system (unless you have an upgrade) but its worth checking

[Jkloc23]

Start with bleeding and making sure the hydraulics are all working properly. If that's all good then yeah next step would be to drop the transmission.

If I had to guess (and assuming all hydraulics are good), I would say that there's been some sort of failure with your pivot fork/pin that's not allowing the clutch to fully disengage.

Edit: Oh and if you have a clutch stop, make sure it hasn't moved and is allowing for the clutch pedal to actuate fully.

Yea I’m going to pull the slave tomorrow to check it out and then bleed the system to see. I just realized the car is actually missing the clutch stop. Wondering now if the slave cylinder didnt over extend and push through the clutch fork.

[Jkloc23]

I had to spend extra effort to get all air of out the slave cylinder after a clutch line upgrade. Unbolt the slave from the housing, hold in your hand and tilt up so the bleed nipple is up, loosen the bleed and gently tap the housing with a hammer, then have an assistant depress and hold the clutch, you tighten the nipple, then clutch out. Repeat a few times. Ensure the assistant doesn't depress the clutch when the nipple is closed. You don't know if or why air was let into the system (unless you have an upgrade) but its worth checking

No upgrades have been made recently but I will try that when bleeding the clutch.