Strange clutch problem

[98 3.8]

So, this morning I get in my car to run a quick errand...it's a 98 M5 with 173K miles and a new clutch as of around 140K miles.

The shifter's in second gear. I push the clutch in all the way and turn the key.

The car lurches forward and stalls. I slam on the brake and take my foot off the clutch. The clutch stays floored.

So then I try popping the shifter out of second. As you might expect, it was engaged. I force it out of second and start pumping at the clutch. It slowly returns back to its original (engaged) position.

At that point I decide to go ahead and run the errand. The transmission works perfectly normal, except for the fact that the clutch seems to be just a little firmer than normal and the point at which it engages seems to be a little higher.

I was driving pretty hard last night, btw. But everthing was working fine then.

So...any ideas on what my problem was/is?
[img]graemlins/popcorn.gif[/img]

[shenanigans]

sounds like a possible hydraulic issue.

[98 3.8]

Yeah, that was my guess. I may try bleeding the system this weekend...any good writeups out there?

[black98V6]

do you have the original master cylinder? if so that might be it, when my slave went it was all at once and no amount of pumping would make it work. Either way if the car lurches when the clutch is depressed then you aren't disengaging that's either master or slave, I'd bet master espicially if it's the original.

[98 3.8]

I'm pretty sure it's the original master. The previous owner replaced the clutch, so I'm not 100% on that, but it's probably original.

How much does the master cylinder cost? Do I have to remove the tranny to get to it?

[loser]

id change the master cylinder first. no you dont have to remove the tranny to replace it. it goes through the firewall. kinda hard to put back in becuase of that stupid U bolt but its not hard to change. i dont remember off hand what i paid for mine. probally around $50 maybe a tad more. i know it was under $70 at my local advanced auto.

[98 3.8]

Alright, ordered the master from NAPA last night on my way home and will pick it up this morning. [img]graemlins/rock.gif[/img]

It was about $100 after the shipping charge and tax. I guess I coulda gotten it cheaper, but I'd rather pay the extra money then get stuck halfway between home and my school dorm this week. (about 1:30 hrs apart) :D

With a vacuum bleeder I don't need someone depressing the clutch to bleed the system, right? Just keep the clutch fluid level nice and high?

[98 3.8]

Update: Installed the new master cylinder yesterday. Wow, that U bolt really was a PITA.

Just drove almost 100 miles back to school today and it's working great. Haven't had the clutch stick again, so it looks like the problem's solved!

Thanks for the input guys.

[loser]

yea it took me forever to get that stupid U bolt in. i couldnt keep it level, so i'd get one side in, but the other side wouldnt line up with the hole anymore. glad everything worked out good and is doing great now. this seems like a common problem with theses cars.

BTW, when i first put my new master cylinder in, i only bled it once, went out the next day to get it out of the drive way and back in the yard ( im only 15 cant drive yet ) and it didnt want to go into reverse, so i had to pump the clutch a few times, to build up pressure i guess. after that i bled it like 5 more times and now its good. i did it the old fasion way, with my brother in the car working the clutch. you might good luck.

[98 3.8]

Yeah, I had to bleed the same way. I actually bled enough to fill a coke can right away. Then I went to see how firm the pedal was and it was waaay soft and wouldn't go into any gears. I was thinking I had done something wrong, but after I pumped the pedal a few times, it regained the old stiffness and has stayed stiff.

[98 3.8]

Okay, well after a few weeks of driving, I have realized my problem has not gone away.

Once again, the clutch pedal will go all the way to the floor occasionally and the actual clutch itself stays engaged. This has only happened in first gear when I've had above average throttle.

In addition to this, whenever I start up my car to drive it, I hae to pump the pedal a whole bunch to get it stiff enough to get into gear.

I replaced the master cylinder and that did not help me.

So, what should I do now?

The car has a lot of miles on it, but the previous owner claimed to have replaced the clutch at around 140K miles. I'm not 100% sure that he did, though. Or could it be that I have destroyed my clutch by shifting like a maniac?

[ December 10, 2005, 12:37 AM: Message edited by: 98 3.8 ]

[Razzer]

It may be the slave cylinder that engages the cluth. If labor is cheap there (CA =80$+ per hour) I would replace the clutch and the slave cylinder assebly next to the clutch, check the push link that connects the master cylinder tube to the tranny. It definitrly sounds like a hydraulic issue, see if your going through cluth fluid. good luck

[Twitch]

I know exactly what your problem is. This same thing happened to me about a week ago. I was driving hard also and didnt notice it til I slowed down. Its your clutch return spring. If you put your head down in the pedal well and look up the dash you will see these springs that pull your pedals back to the original position. The return spring on your clutch pedal probably snapped. Parts are pretty cheap and it takes about 10 to 15 minutes to do. Wish I had seen this earlier, could have saved you some $$$ and the work.

[ December 10, 2005, 07:49 AM: Message edited by: Twitch ]

[98 3.8]

It's not the clutch spring. It is intact and working.

I took the car out and drove it a bit to see if I could replicate the problem...

Basically, in the process of driving, I'll notice that the clutch pedal is engaging closer and closer to the floor. Then it will stick to the floor and remain engaged. In order to get it working again, I have to repeatedly pump at the floored pedal before it starts working again. After pumping the pedal, it works as usual and engages in the correct place...until the next time it does this.

Please help!

I'm thinking about replacing the slave cylinder. How hard is this to do?

[loser]

im betting its the slave. the two most common fix's are the master and slave. sence you already replaced the master, its probally the slave. i dont know much about it, but you have to drop the tranny. do you have a hayne's book? im sure that would give you an idea on how to go about it.

honestly, this post kinda scared me, im not 16 so i cant drive my car, and i only put about 15 miles on it sence the new master cylinder, i hope i dont have the same problem as you now.

keep us updated, ill help as much as i can.