[Zeph]

I had my clutch replaced at about 2300 miles, it just blew out one day when I tried to "launch" the car.

Ever since the forward (R, 1, 3, 5) have been a tad harder to get into but seems to smooth out once fully warmed up.

Anyway, yesterday I noticed that when I went to start out in 1st gear (multiple times) it would kinda shake the car while engaging the clutch. This was slow engagements (normal driving) and not trying to launch the car or even start out fast. I was in my neighborhood pulling out from my house and at a couple of stop signs. It kinda cleared up once the car warmed up a bit. I only made a quick trip to the convenience store and back so I didn't drive it for very long. I hope this doesn't repeat itself when I drive my car again. I only have about 9500 miles now (so like 7200 on the new clutch) and I have not even been to the drag strip or anything with this current clutch.

I don't think it is slipping because usually when a clutch slips it just rev's up without moving or hesitates to move. This is different...

[Peej]

we also had this issue and the first time the dealer put the whole driveline under pressure and found nothing, the second time they decided to change the clutch under warranty and the issue went away

[GeorgiaTech335coupe]

After I got my clutch replaced (with a remanufactured oem) from BMW, I kinda noticed that I would almost stall a lot more than I used to, which was pretty much never. Basically, I've noticed the same thing. I figured it would just go away with time and I have seen improvement.

[Peej]

i think that Zeph means that when you release the clutch up to the engagement point the whole car vibrates until the clutch is fully released? is it also most noticable at mornings when the car has not been used for several hours?

[BavarianBullet]

Originally Posted by Zeph

I had my clutch replaced at about 2300 miles, it just blew out one day when I tried to "launch" the car.

Ever since the forward (R, 1, 3, 5) have been a tad harder to get into but seems to smooth out once fully warmed up.

Anyway, yesterday I noticed that when I went to start out in 1st gear (multiple times) it would kinda shake the car while engaging the clutch. This was slow engagements (normal driving) and not trying to launch the car or even start out fast. I was in my neighborhood pulling out from my house and at a couple of stop signs. It kinda cleared up once the car warmed up a bit. I only made a quick trip to the convenience store and back so I didn't drive it for very long. I hope this doesn't repeat itself when I drive my car again. I only have about 9500 miles now (so like 7200 on the new clutch) and I have not even been to the drag strip or anything with this current clutch.

I don't think it is slipping because usually when a clutch slips it just rev's up without moving or hesitates to move. This is different...

This sounds like garden variety clutch chatter.

It tends to happen on racing or high-power street/strip clutches if the materials used are certain types. It shouldn't happen on a typical OEM organic clutch and if does it's often because of either greasy fingerprints etc on the clutch disc, pressure plate or flywheel mating surfaces or perhaps from not resurfacing the flywheel when changing the clutch (or both).

Given you had the clutch replaced at such a low mileage, the dealer could have went cheapo and just replaced the disc without changing out the pressure plate and/or resurfacing the flywheel.

Regardless, it's chatter and it's not acceptable on a $50k car. I suggest taking the SA for a ride if you can reproduce it. It might go away with mileage if it's very mild but quite possibly not.

Good luck and let us know how it works out.

[scheherazade]

use more rpm, and slip it more.

it's grabbing at low rpm, and putting torsion forces on the driveline. when the force accumulates enough, it slips because the clutch isn't *fully* engaged. so you get a pulsing sort of jolt-jolt-jolt when you start.

mo-powah or less clutch engagement, or a bit of both.

Nothing crazy tho... don't burn it.

-scheherazade

[Zeph]

Originally Posted by Peej

i think that Zeph means that when you release the clutch up to the engagement point the whole car vibrates until the clutch is fully released? is it also most noticable at mornings when the car has not been used for several hours?

Yes, you pretty much got the idea. This "new" clutch worked fine for over 7k miles and did it for the 1st time yesterday while the car was cold (first drive of the day). I will see how it feels tonight when I go out... as far as grease/fingerprints or them not turning the flywheel, etc. I think those would have been noticeable problems right when I got the car back. Remember, it was replaced at 2300 miles and I am now at about 9500 miles.

If it continues my car will go back to the dealer (this will be my 4th trip in less than 1 year, less than 10k miles ). I had LPFP, clutch, then HFPF all replaced already.

[shifterboy45]

sound like one of 2 (or both) problems exist-- the flywheel is glazed -- the friction surface has been heated to the point of drawing the binders out of the pressure plate and plastered themselves on the face of the flywheel, resulting in a glass like surface contact area. similar to happens when brake pads are heated (overheated) up enough of glaze the brake discs -- causing a vibration in the steering wheel on hard decel at speed.

or there is something bad going on with the dampners in the dual-mass flywheel. if a dampner spring set fails, the shock load is not properly distributed -- clearly evident by a ratcheting type engagement (letting out on the clutch)...

[Zeph]

it seemed fine last night and today... so I don't know what might have happened. Maybe it did just get hot and glaze again, but hopefully I was able to wear some of that off with some spirited driving

I also thought about possibly something with the "uphill assist" or whatever it is called that helps you not roll backwards when starting out. Who knows.