[Smok335]

Hey guys, here again looking for some advice. 07 335i 6spd. Drove the car yesterday, no problems at all, nothing serious as far as hard driving goes either. This morning I go to turn the car on, press the clutch down and it felt fine. Pressed the start button and the car lurched forward under the power of the starter (foot still down to the floor).. Realized immediately something was up so stopped trying to start it and took my foot off the clutch pedal. The pedal would not come up under it's own power and had to do it by hand, can press it down with minimal resistance but will not return.

Obviously the clutch itself is not fully disengaged due to the car lurching forward, so thinking it's something hydraulic related and not a clutch/ Throwout bearing problem. That sound right to everyone? And any specific area I should check/ easy ways to narrow down the diagnosis?

As always, thanks for the help in advance.

[NikMN]

Check brake fluid level first.

[Smok335]

Interesting, hadn't thought of that. If there is a problem with the brake fluid level I'd think I'd feel something in that pedal as well yeah?

[NikMN]

Maybe a leak from corroded hard line or slave cylinder. (Plastic) I would check level of brake fluid just to rule them out. Maybe fluid is being pushed out instead of pressing slave piston.

Someone correct me if I'm wrong. Both systems use same tank but they not tied together

[PhaseP]

Someone correct me if I'm wrong. Both systems use same tank but they not tied together

Yes same tank (reservoir) but clutch uses a small partition of it that is towards the firewall side of the reservoir. This is done on purpose, so that if the clutch lines leak it will only empty its partition of the reservoir, brakes won't be affected.

And because of that when checking the brake fluid level for the clutch, need to look at the level where the clutch line is connected to. Brake fluid level may be just fine but clutch area empty.

From the description of OP, it had a leak at clutch hydraulic system that emptied the lines.

[Smok335]

Originally Posted by PhaseP

From the description of OP, it had a leak at clutch hydraulic system that emptied the lines.

Kinda what I was thinking. Checked brake fluid last night but not the separate partition, so I'll check that tonight. Hoping it's empty because that would likely mean slave and or master cylinder and I'd much rather it be that than something more serious inside of the bell housing. Planning to pull the motor this winter already, so just hoping nothing serious arises before then.

[Smok335]

Update. Finally got it on jack stands. Bad Slave Cylinder. Thanks for the help guys!