Air in the clutch master can also cause funky behavior like this. If brake fluid is below the clutch tap on the reservoir, it's possible that you're drawing air into the master...
Not cold here, but I haven't checked the fluid. I need to do that. For some reason, I didn't think to do it. It just didn't seem like low fluid would do that, but I should have done it just to rule it out.
My first concern was that it was momentarily keeping my clutch from fully engaging. It is only for a second, but over time, that could add up to damage.
Looking at the tach, it does not appear that the clutch is not full engaging before the "thunk." I'm reasonably sure that no damage is being done to my clutch. But, I still don't like it.
2007 model, 104,000 miles. It literally just started suddenly today. No warning. It drives just fine, with no unusual clutch actuation, other than that hang-up in the pedal.
Once again, the problem seems to have solved itself. I had a problem with my high-beam headlights back in October of 2016, and it just magically went away.
I drove to Fort Worth again today, which is a 50 mile drive. It didn't hang up once. I don't like not knowing what was wrong, but don't know how to fix a problem that goes away on its own.
I'm going to take it to my MINI dealer for a fluid check and top-off. They do it for free, and will even wash and vacuum the car, if I want. I usually just get the vacuum done, since their car wash is a bit on the harsh side.
Thanks for the advice, everyone. I may never know why it did what it did, but at least it didn't cost me any money... yet.
Well, the problem came back, but I now know what the problem was.
Today, 50 miles from home, a bolt fell from under the dash onto the floor. It is one of the bolts that attaches the clutch pedal arm to the car. Lucky for me, I shot a car at a restoration shop, and one of the mechanics figured it out and fixed it for me. The clutch worked for a about an hour after the bolt fell out, but at the restoration shop, I couldn't start the car, because of the safety switch that tells the computer that the clutch is depressed was not able to do its job.
