Just got this 92 MX3 GS 5 speed. It shifts through the gears smoothly while off but after starting the motor it won't go into gear with the clutch depressed the whole way. Then a friend suggested starting it in gear to see how it acts and when I did that the car started moving immediately after starting it. And this is while I have the clutch pedal to the floor. This suggests obviously that the clutch isn't disengaging. Where should I start looking? I was thinking slave cylinder but not sure as I'm new to hydraulic clutches.

 

Is there any hydraulic fluid in the resevoir? The resevoir for the clutch system is shared with the brakes. The clutch part of the resevoir will be the back 1" of brake resevoir. Maybe is dry due to release cylinder leakage and now have air in the system.

 

The fluid level is just above the minimum line. I'll add some tommorow but doubt it will make a difference

 

Make sure the level at very back of resevoir is ok and not in the front section. Fluid level can look good at front and still be low in the back. Helps to shine a light thru the side of resevoir as will show the level better. Adding fluid at this point will not help if low as there is probably air already in the system that will need to be bled out.
You might also want tolocate the clutch release cylinder and see if it is leaking. This is the most common problem with the symptom that you describe. It is located on the front, side of the transmission on the radiator side and just above the transmission mount. See drawing below. Pull the black rubber accordian looking boot away from the body of the release cylinder and see if any fluid runs out.

[IMG]local://upfiles/1377/BBA934B1DA8747BDB1048792012737EC.gif[/IMG]

 

I checked that and the part isn't even connected in. I'm not too experience with hydraulic clutch systems but it appeared either broke or somehow came loose(which I doubt). It had fluid all over it so I figure it needs replaced. Now you refered to it as the clutch release cylinder, is that the same thing as the clutch slave cylinder or is it something totally different? I was pretty sure that that part was the slave cylinder and have actually ordered one and was gonna have a shop install it tommorow. I'm starting to miss my old sentra. Cable clutch's are so much easier to diagnose haha. But I know once I fix this I'll love the car.

One other thing, it has a really noisy rattle. I haven't gotten it up on a jack to check the heat sheilds but the rattle somewhat worries me. I can feel it through the shifter and it sounds like it's directly below the motor/tranny. While off it shifts smooth and the motor while running seems really smooth too and I don't feel the rattle through the gas pedal either. I can't yet test the shifting while driving as I first need to fix the clutch disengage issue. Other than heat shields any suggestions on what I should check?

 

Sounds like you found the problem with pedal going to the floor if release cylinder is not even bolted up to the transmission!! Yes the release cylinder is the same thing as a slave cylinder just difference in terminology.
Only way to find an obnoxious rattle is to get under there and locate by ear. Could be virtually anything. Maybe the shop that is replacing the release/slave cylinder could take a quick look while it is in there.

 

Well the good news is the slave cylinder is replaced. The bad news is themechanic found the rattle in the process. The shift fork is broke. I got an estimate from the dealer garage and they said it'd run $421.33 to have them fix it($19.75 for the part and $69.95/hour labor for 5.4 hours). My question now is, is this a difficult repair? I've gone as far as an engine swap on my 97 sentra(automatic) and cam shaft swaps so I'm pretty good with doing stuff myself but never messed with anything like this before. Any insight I could get would be great. And thanks for the help so far.

 

If the shift fork is an internal transmission component then would probably be better off letting them get in there and repair. If they are only talking about the shift fork for the release bearing that the slave cylinder is pressing against then is justa simple matter of taking the tranmission out and putting a new one in. If you can pull the engine on your Nissan, am sure you could handle transmission R and R on the MX3

Must be the release fork inside the bellhousing the slave cylinder pushes against and actuates the release bearing as the suggegsted retail for a that part on a 1.8 V6 is $19.75 and internal trans fork are much more than that.

 

Yeah it's the part in the bell housing. I talked with the mechanic that found it and he said it's a simple fix so I've ordered the part and I'm gonna order a new clutch kit to install while I'm in there. I'm planning to do it next weekend and hopefully after that she'll be good to go. Thanks for your help.

Mitch