don't know if the sincros are bad or something else because it is hard to get it into gear specially the 1st and 2nd and reverse, with some effort i'll get it in but sometimes when changing from 1st to 2nd there is a grind (with the engine off i can go through the gear with no problem)..i already change the tranny( used MTF from honda), clutch, and differential fluid but is still the same thing ahh and when i'm getting it into gear i hear a low hissing sound that it wasnt there before..what could the problem be and how much i'm gonna spend for this..thanks..
ps my 00 s2k has 78000 miles.. i did search for answer but most of the people with this problem dont say what was the solution, and some of them was fixed by a simple change of fluid..

 

It's important to search your topic prior to posting. Everyone wants a microwave oven response - but put out the effort, read about your problem, and then come to the plate with questions that weren't answered in previous posts.

If you've done a search - please state that in your post so you don't get the above note.
The search function can be painful (sifting through the false-positive hits) - but it works. Trust me, there's a LOT of information on your problem.

With all that said...

Rule of thumb with any problem - go from the simplest fix to the most complex.
You did this by changing fluids.
That didn't work for you so the next step would be to try a different transmission fluid. The best options are Honda's new MTF, Amsoil MTF (www.amsoil.com), or GM Synchromesh Friction Modified (GMSMFM in the forums). Do a search on these fluids to get more info.

The next step becomes more expensive and takes a trained (trusted) professional (or someone with a lot of experience) to troubleshoot.

A worn clutch can sometimes unmask problems with weak or damaged synchros before the clutch fully advertises its about to die on you. However, a worn clutch would likely show problems in more than 1st, 2nd, and reverse gears. You mentioned you changed the clutch fluid - but I'm assuming the clutch is the factory one.
The "hissing" sound might be one or more of the bearings making noise (possibly a worn throw-out bearing...) I couldn't say for sure unless I heard it in person. It could be a noise you didn't pay attention to until you started having problems, it could be any number of things - it's hard to say.

If changing to another fluid doesn't resolve (or at least improve) the problem - you may consider replacing the clutch (disc, pressure plate, throw out bearing, pilot bearing, pressure plate bolts, flywheel bolts if you have it removed for resurfacing - always) if it's the original clutch.
Here's something to consider though - the most expensive part of the clutch job on the S2000 is the labor to remove and re-install the transmission. Depending on your finances - you may want to consider replacing or repairing the transmission while it's out.
A low-mileage transmission typically runs around $1500 (from a reputable source). The Hard Top Guy is a great source: http://www.hardtopguy.com/store/home.php?cat=11
Jeff is the owner - I bought an '04 transmission from him for my '03 - Fantastic vendor!
Good luck.

 

Here's an easy and inexpensive thing to check - make certain that your clutch fluid is flushed and bled properly. The clutch is not easy to bleed, so make sure it's done correctly.

 

edited

 

Great point - keeping with the first principle: KISS.
Thanks Doc.

 

well it took some time but finaly found the problem ....it was the clutch disc


damage in the pressure plate!!

 

it sound like its the fluid i had the same exact problem a few months back i looked and saw the fluid was very low and i cound barely get it into gear so i put some brake fluid in and flushed and bled it and havent had a problem since

 

you said u swap the clutch in the op .. is that picture of the new clutch.. that went bad?? or poor install??

 

Same thing happened to my ACT clutch in my integra! (well not quite 100% the same piece broke off, but i had the same symptoms with my broken clutch) what clutch is this?

 

this is the OEM clutch from exedy..