I have a problem with my car. Hopefully, someone can help me figure out what the problem could be.

The car: 2004 S4 6 spd manual with 133xxx miles

The problem: The clutch doesn't seem to be releasing at all. When I press in the clutch pedal, it feels very light. I cannot physically put the car into gear while the engine is running, but it goes into gear just fine when the engine is off.

The cause: This happened suddenly while I was driving at around 75mph on the highway and went to downshift. I may have accidentally tried to change into a lower gear than I wanted (I don't remember what gear I was going for because I was pissed off that a van just cut me off), but I was probably going for 3rd or 4th and may have shifted into 1st or 2nd accidentally. I coasted to the breakdown lane and got towed home.

Additional diagnostics: I wanted to test that the clutch was holding, so I put the car into 1st gear, started the engine, and the car moved forward. Note that the clutch pedal was completely depressed while doing this (necessary to start the car).

As a side note, the brakes work fine (I believe they use the same hydraulic fluid as the clutch) so at least the hydraulic system isn't leaking.

Just for kicks, I attempted some vag-com diagnosis, but there really isn't anything to scan except for the engine, which is working just fine. Let me know if you need any more info.

Thanks in advance for your help.

 

it is either the pressure plate fingers broke or the hydrolic system, it is seperate from the brake system so dubble check on that first.

 

Thanks for the reply. I spoke to two mechanics about it and asked for an estimate of how much it would cost (they priced it out as a clutch job) and they both said it was the most labor intensive clutch job they've EVER seen. The higher of the two estimates was $3500.

Being a relatively poor college student that is capable of turning a wrench, I'm going to be pulling the transmission on monday to figure out what the problem is. Has anybody done this on a B6/B7 S4 before? Are there any special tools I need? I just bought a set of triple square sockets to remove the axles, a clutch alignment tool, a transmission jack, and I have lots of other tools like metric sockets and torx sockets and whatnot. Is there anything else I should look out for?

Since I have a bentley manual for my car, I printed out the instructions for removing the transmission and it was 20 pages long!

 

I would make sure that the slave cyl. is depressing before you pull the tranny you can access it fromthe left side, youmight have to pull the left axle to see it good, but that is less work and alot cheaper if it turns out that you only need a slave or master cyl or even just bleed out. I always rule out the cheap and easy first

 

Thats a good idea, since I would have to remove the axles anyway. Thanks for the advice. :-)

 

Here is the solution to my problem:

I finished pulling the transmission today and noticed that the slave cylinder had melted. When I removed the slave, it actually fell apart. Obviously, this would prevent the clutch from disengaging.

Since removing the transmission on a 4.2 S4 is so labor-intensive, I decided to check the clutch, pressure plate, and flywheel for wear/damage/etc. I had also noticed some large (like one square inch) chunks of clutch fiber in the bell housing. When I unbolted the pressure plate bolts, the clutch fiber completely fell apart on one side of the clutch and the other side showed heavy signs of wear as well as physical damage. Needless to say, I'll be replacing all of my clutch components. The flywheel actually looks like its in really good shape (and a new fw costs around $1000), so I plan on cleaning it up a bit with some steel wool.

After talking to some of the area dealer parts departments, it looks like a clutch, pressure plate and bolts, release bearing, and slave cylinder will cost just under $700. These can be found cheaper on sites like ECS Tuning, but I don't have the time to wait for shipping.

If anyone plans on doing a clutch or pulling the transmission on a B6/B7 S4, its very difficult, but not impossible with the proper tools. PM me if you have any questions or would like a .pdf of the bentley manuals instructions, which are very helpful.