My 03 c320 clutch is making a rattling sound today.
Heres what it is happening. No gear selected clutch out or partially out = rattle noise. Clutch all the way in = no noise. In gear = no noise from clutch.

Any ideas?

If you are rolling in neutral with the clutch out does it make the noise?

worn out release bearing perhaps

Yes, sounds like a bad throw-out bearing. Now matter how you look at it, you have to drop the tranny, at that point, you might as well replace the clutch, throw-out bearing, pressure plate, turn or replace the flywheel. I made the mistake once of just getting the one thing that was broken fixed in my tranny and a month later it had to come out a again so what could have been a $50 part turned into a $350 repair. What causes this to go out is riding the clutch but if you prefer to blame the car, it can be caused by improper adjustment and misalignment.

sidestepping the clutch can cause that also. my focus has been like that for years. no problems outside of the slightly annoying noise in my case though.

Thanks for the replys.
Today it didn't seem to make the noise like yesterday.
I got this car about 6 months ago used with 59k on it. So I don't know how it was driven previously though.

I am a vetran stick shift driver with over 300k on stick.

I looked up the price of clutch kits and only ones I could find were 800+. Seemed a bit on the high side of things.
Anyone ever get theirs replaced?

When I sold my e36 it had 163k on the original clutch with no signs of slipping at all.

My friend has a Subaru and his OEM one cost like 1200 from Subaru. I can only imagine things are going to be more expensive for the MB

How many miles is 163k?

i would venture a guess that 163k means miles, as in 163,000.

150k+ and going strong on the clutch on the focus. <5k on the benzo's clutch

The MB throwout bearing is $214 list price, pressure plate is $565 for C230 or $276 for the C240 (they never made a C320 manual trans car in 2003), clutch is $320. You can probably get 20-25% off on parts online.

That's what i was gonna say. Blame the previous driver. :-p

Is this more noticeable when the transmission is thoroughly warm? It might just be good old layshaft rattle & not much to worry about. New primary shaft bearings & needle rollers might improve it but it might be nothing to worry about.

lol I thought is was in KM (not miles) for some reason

Yes when its warmed up it is more noticible.
It doesn't seem to do it all the time.

If it is layshaft rattle it is going to tend to make more noise when the gear oil is warm & thinned out. It will also be very dependent on idle speed and idle smoothness. If you leave the car in neutral - clutch out & it is rattling - increase revs very slightly by accelerating until a fast smooth idle is achieved. If the noise reduces it is likely layshaft rattle. If it is layshaft rattle I would leave well alone unless it gets worse & develops. Most manual cars do it to a greater or lesser extent & it depends how sensitive you are to it. Some cars in the same make & model can make more noise than others and yet have nothing wrong with them. Alfas are chronic in this regard but Alfa owners just live with it.

How loud is it? I know this is difficult to describe