E46 M3 clutch question

I recently bought an E46 M3 convertible with 85K miles. The clutch slips when driving/shifting aggressively, but it's not an issue in normal commute type driving. I have plans to do a 2500 mi vacation trip in a couple months. I will have my 11 and 9 year old kids with me. My hope is to not replace the clutch until next winter's down time.

Are there any obvious failure modes for the clutch that are catastrophic? Or can I assume that as long as it's doing ok it's reasonably safe to take it on the trip without replacing the clutch first? Any thoughts on this?

Have you investigated other contributors to slipping? Low fluid, toast master cylinder, etc.?

In reply to Mitchell:

Wouldn't those types of issues just cause problems with disengagement?

I suppose if the master cylinder piston didn't fully retract it could cause this. Or if something is misadjusted on the actuation end (not sure what that looks like in this car). I'll have to look at those things.

If it is that kind of thing, the throw out bearing would always be spinning and wouldn't last too long. Any other failures that could leave me stranded?

If your trip includes steep grades, do it now. You risk getting stranded, damaging your flywheel (not cheap to replace). If you do the repair early, it is likely to be less expensive. Waiting only risks $$$. If $$$ is no object, just drive it until it fails and write a check to fix it, wherever you are.

I would not drag the family out for a 2500 mile road trip in a car with a dying clutch.

It will be driveable, until it isn't

I suggest that you get the clutch fixed right before you go on the trip. It would be a pain in the a$* if your clutch quit grabbing completely when you're 100+ miles away from a city.

Kenny_McCormic wrote: I would not drag the family out for a 2500 mile road trip in a car with a dying clutch. It will be driveable, until it isn't

Just had that happen, in fact.

First there's denial. Did my clutch just slip? No, my foot must have slipped.

Then anger. Darn, you, clutch!

At the fifth stage, you finally bite the bullet and get it fixed.

Well, of course you guys are right. I just don't want to do the work right now. Thanks for pushing me the right direction.

David S. Wallens wrote:

Kenny_McCormic wrote: I would not drag the family out for a 2500 mile road trip in a car with a dying clutch. It will be driveable, until it isn't

Just had that happen, in fact. First there's denial. Did my clutch just slip? No, my foot must have slipped. Then anger. Darn, you, clutch! At the fifth stage, you finally bite the bullet and get it fixed.

What are stages 3 and 4? Hopefully they don't involve ditching it in someone's driveway.

You have a couple of months. Buck up and fix it. This is the season where the M3 needs to breathe! Why tiptoe around a funky clutch?

Well this got interesting. If you google E46 M3 clutch, you find that it's a pretty common to remove the "clutch delay valve". This seems to be a device to smooth out clutch operation, but performance oriented drivers claim that the clutch is much more predictable without it. I figured that since I only experienced the clutch slipping on aggressive shifts, I might as well try removing it.

You know how you get excited about the idea of a simple fix really working and not having to do a much bigger job? And of course you know how that ends up being reality no more than one time in ten.

It seems that this was that one time. Half an hour and a buck worth of brake fluid later and I can't get it to slip.

I'm guessing that gunky fluid through the delay valve combined with a worn but not shot clutch created the issue. From the googling it appears it's quite common to replace clutches at about 80k miles, and now I wonder how often that could be delayed for another year or two.

Now to drive it aggressively for the next few days to be sure it isn't a problem anymore. I like excuses to drive aggressively

Excellent! Back in the day I took a clutch delay valve out of a 240 sx. I coukd not tell a dang bit of difference. Glad it worked for you!

I forgot to remove the clutch delay valve on my E36 when I did the clutch and flywheel. I finally figured out that you have to let off the clutch pedal suuuuuper slow so it doesn't clunk and buck the car some. It's tricky since it engages before the friction zone.

I'm revisiting this thread to say the removal of the clutch delay valve only bought a little time. The slipping came back and then seemed to be getting a little worse, so I bit the bullet and pulled out the transmission. It turns out that the clutch was very oily, so that turned into an oil pan gasket change, too (now I know why dealers get ~$1000 for that job and it's only a $50 part). All back together now, and the clutch works well and no drips. That certainly reduces the angst of the vacation drive.