Inconsistent clutch engagement
First off, new member here so Hello to all.
I have a 2002 325Ci, completely stock, manual, with 67k. Over the last few months I've noticed the engagement point on the clutch seems to frequently shift. The pedal can be anywhere from just off the floor to almost fully out. This does not change with temperature (ambient or operating). It can vary that dramatically from one stop light to the next. Although the problem is most noticeable in 1st, it has also evident in every other gear change. The clutch has never been worked on. There is no "clunk" or other noise accompanying. There is no evidence of slippage. I let a friend drive my car a few times and I was riding with him once and noticed that he would downshift to slow the car but not blip the throttle, letting the clutch engagment "wind down", if you will, the engine revs in conjunction with heavy braking. Needless to say, he doesn't drive my car anymore.
I'm a fairly proficient driver in a manual as I have been driving them almost exclusively for around 15yrs, however this new problem makes it awfully difficult to drive it very well as far as gear changes are concerned.
What might be wrong? How does one fix this problem? How concerned should I be? Is what my friend did at all related to the possible problem? Any other info is greatly appreciated!