Loud Clunk/Pop when Clutch Depressed

This is regarding my 96 BMW 328i. It has approximately 177,000 miles on it. Over the past year, I’ve replaced the cooling system, fuel pump, alternator and trans fluid for kicks. So, I’m understandably frustrated with it. Anyway, to my story:

On my way into work, whenever I pressed in on the clutch, it would make a loud clunk/pop and freak me out. I turned around after 1/4 of the way and swapped cars.

My mechanical skills are maybe 3 on a scale of 1 to 10. I’m not afraid of changing oil, brake pads, transmission fluid, changing an alternator, etc. But I want to have someone to blame for anything that involves anything within the engine block/head/transmission continuum.

I noticed that a heat shield was loose between the driveshaft and the exhaust. I rapped it with a hammer, and the heat shield didn’t make a noise anything like I’m hearing. So, it doesn’t sound like that’s the real culprit here.

  1. What is likely causing the issue?
  2. How much would a fix cost? hundreds? thousands?
  3. Given #2 and that I’m planning on getting rid of it, should I fix it and sell or just sell it as is?

What’s going on besides the clunking noise, if anything? Did you feel shifting was harder than it used to be, or that you had to depress the clutch pedal further than in the past, or that it was harder to depress? Did it feel as if the car had less power, especially in first gear? I realize you just drove it right home when the clunking started, I’m most interested in how it felt to you in the weeks before this happened. Clutches usually die slow deaths, and often the symptoms are overlooked until something dramatic happens.
So, how did the car feel prior to the clunking? If any of the symptoms I mentioned seem about right, you probably need to replace the clutch.
As to what’s involved, here’s a good link:
http://www.pelicanparts.com/bmw/techarticles/tech_main.htm

As to the cost, it depends. A standard clutch replacement should cost around $2,000 for your car, especially if you go to the dealer. You might shave off a few hundred bucks at a good local garage. You might do it yourself at a fraction of the cost (it’s mostly labor; the parts are not that expensive).

As to whether it is worth it to keep the car and invest the money on the clutch, that depends on how well the car has been maintained up till now and it’s overall condition. Also how much you trust it.
If each is pretty close to excellent, I would invest in a new clutch and keep the car. If not, consider the alternatives. What can you afford instead of this car?

Shifting (particularly into first) certainly was getting more difficult, but I didn’t feel like the clutch was slipping or chattering at all.

Lots of things it could be, but at 170K, the clutch is suspect and replacement is probably called for.

If your skills are a 3, you need to have a pro do this.

But before you do, get a look inside the bellhousing. See if you have a broken spring or a wornout throwout bearing. You might need someone operate the clutch while you are under the car.

What it sounds like is the slave servo is going out. These occasionally start requiring more pressure to activate them. Sometimes when they get old, they get sticky. When they do, it can cause a clunking sound and stiffness of the pedal as it will take more pressure to get it to “fire” as I call it. Then they suddenly pop open and engage the clutch. There is another way to tell if this is the issue, if you “pop” the clutch, does it kind of take a second before the clutch engages completely?

I would agree about the slave cylinder, especially if it does this when the engine is off and the car is still. The part about being harder to get into first gear is another clue to back this up.