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Discussion Starter #1
Hey everyone, I just got my M5 (this sunday. 2001 black) and I can't stop smilling every time I look at it. I love it.

I've been driving it around town, no freeway yet. I have a question about shifting. Whenever I go from 1st to 2nd at anything above 2,000 RPMs it kind of stops all of a sudden, slows down, then keeps going steadily. Same with shifting from 3rd to 4th, and 5th to 6th. It's getting kind of annoying, especially since my old 97 F350 didn't have that problem. I could get upto 4,000RPMs and then shift and the truck would just smooth out and show no signs of slowing down, it wouldn't just CLUNK and slow down abruptly like the M5...almost as if applying the brakes while shifting. Any suggestions on why this may be?

Thanks,

Rudy
 

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Hmm, that's kinda odd. When you shift, are you getting a DSC light that flashes on the dash? Abrupt clutch engagement will trigger DSC, and past 2000rpms there is enough power to do so. Try turning DSC off and see if that helps. If it does, work on engaging the clutch smoother. That might or might not be the problem, as it shouldnt do it from 5th to 6th.
Are you letting the rpms fall too low when you shift, ie when you take the clutch out do the revs get pulled back up? If you try shifting a bit quicker to keep the revs from falling down too low.
You might also have worn/blown tranny mounts. Get under the car, and check the mounts for stretch marks or torn rubber,
Try changing the way you drive a tiny bit and see if your actions can smooth out the shifts. Each stick drives differently. Good luck!
:cheers:
 

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not sure i'm really understanding. Are you completely lifting off the throttle, leting the engine rev down to idle while you shift, then letting up the clutch without matching the revs? I've never really had an issue with the car dramatically slowing while shifting, unless the dsc is kicking in (i usually have it off to avoid this) which would only be if you're driving pretty aggressively.
Mike
 

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Discussion Starter #4 (Edited)
Yeah, I match the revs while shifting and it kind of jerks backwards as if i pump the brake suddenly. I don't understand what could be going wrong.
 

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So if you just take first gear up to 4000 rpms then clutch in and take foot off gas the car feels like it's being braked and doesnt coast?

Sounds like somethings wrong, perhaps the differential is burnt out or out of fluid and ads drag to the drivetrain?
 

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uhhh...did it do this when you test drove the car???
 

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That is really screwy. Are there any loud whining noises coming from the tranny or rear end? Usually when something is dragging that bad there is a noise associated with the dragging. I cant think of anything short of (not really a jab at you Rudy, I'm at a loss for problems) a really poor shifting technique that would do that without making a lot of racket from the failed part.
If it still is under warranty I would get it looked at. Try to find another beast owner in the area who is familiar with their car, have them drive it, and see what things are different from theirs.
:cheers:
 

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Discussion Starter #8 (Edited)
Brother Methias said:
So if you just take first gear up to 4000 rpms then clutch in and take foot off gas the car feels like it's being braked and doesnt coast?

Sounds like somethings wrong, perhaps the differential is burnt out or out of fluid and ads drag to the drivetrain?
If I take the first gear up to 4000 rpms or any other grear for that matter, then clutch it all the way in, take my foot off the gas the car feels like it's being suddenly braked, that's exactly right.
 

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Rudy said:
If I take the first gear up to 4000 rpms or any other grear for that matter, then clutch it all the way in, take my foot off the gas the car feels like it's being suddenly braked, that's exactly right.
Also check for dragging emergency brake. Rear wheels have a separate drum to work the e-brake IIRC. It could cause this, as well as a bad diff. A bad diff should make some noise. If not under warranty, take to your mechanic, get in car, put on lift and engage gears. The mechanic standing outside the car should be able to hear any strange sounds to help pinpoint the problem.
Regards,
Jerry
 

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Here is a thought. Would having high or low fluid in the brake master cylinder cause this? I know the clutch and brakes are tied together, so maybe this is interrelated somehow? I cant think of a logical reason why, but it might be another avenue to pursue.
:cheers:
 

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BmwNut said:
Here is a thought. Would having high or low fluid in the brake master cylinder cause this? I know the clutch and brakes are tied together, so maybe this is interrelated somehow? I cant think of a logical reason why, but it might be another avenue to pursue.
:cheers:
High fluid shouldn't matter, low should throw a light and you would have an awfully spongy pedal if it was low enough to let air in. No harm in checking. A failing brake MC could also cause dragging calipers, but as noted, it should smell, and the wheels should radiate heat and be too hot to touch. Rudy,keep us posted.
Regards,
Jerry
 

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My advise at this point is to visit a professional BMW mechanic for a $100 diagnosis. This may prevent further damage & fees, if something is wrong.

The problem sounds potentially serious, but frankly impossible to diagnose thru a keyboard.
 

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No offense but have you driven a sporty clutched vehicle before? Syncing is a bit difficult on the M5; I have a toyota truck I can up and down shift on without using the cluth with no crunchy grinding sounds. My M5 is easy enough to take out of gear without clutch but much much more difficult to ease in. If I were perfectly syncing I could slide it into gear without a peep. Keep in mind that at the moment the clutch pedal is fully released you want a neutral to slightly positive load on the drive train (zero or slight acceleration) or you will drag down and get tossed forward in your seat. The tranny in the M5 is very heavy duty - don't worry to much about hurting it at low speeds and RPMs - try a round a little bit you may simply be off in your estimate as to the correct RPMs. Just a thought based on my own learning experience with my M5.
ram
PS don't feel bad, I had my shope foreman take my car for a road test a few years ago and it was jerky as hell when he drove it - it takes practice..
 

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If it truly feels the same, i.e, "braking" - just by putting your clutch foot to the floor, something is very wrong. At that point the wheels are disconnected from the engine, and either the transmission or diff have something very wrong internally or a brake is dragging - NONE of which is a problem I've heard of on our cars.

If on the other hand, it only feels like that when you let the clutch up in the new gear, it is your technique - you're engaging the new gear with the engine RPM lower than it needs to be and the result is sudden deceleration. I find the engine RPM in the M5 drops faster than the "natural/gentle" sync speed of the synchros for the lower gears - when I'm casually driving then I almost always add a slight throttle blip while the clutch is still in during a 1-2 or 2-3 upshift.
 

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My guess: perhaps the previous owner changed the flywheel to a lighter one. The reduced mass of the flywheel makes it harder to shift smoothly because it doesnt have the inertia to keep spinning quickly. IN other words, the flywheel slows dows faster than a regular one. Try to not lift the throttle as much between shifts.
 

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I had the same problem when I first test drove my 02 M5. I have driven many cars with manual tranny's (non high performance) and this car was challenging. The car was very "jerky" in the 1-2 and 2-3 shifts and basically it was a learning curve for me. I have since taught the wife to drive the car and she does great. As others have mentioned on this board, it could be a mechanical problem with the car, but I thought I would mention my embarassing mishap on the manual tranny.
 

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What RamM and mako said - I doubt there's anything wrong with your car - as IMO it's just a difficult car to drive smoothly around town and this from someone who's gone 100's and 100's of K miles, all on manual transmissions.
 

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IMO this is the easiest manual car I've ever driven when comparing them to the other sports cars I've owned...94 Cobra (bolt-on's) that made 297 rwhp/308rwtq and a 98 Cobra (bolt-on's and a blower) 438rwhp/405rwtq...These two cars had heavy clutches and rev happy power bands that either bogged (jerky shifts) or smoked tires if you weren't careful with the clutch...

Back the subject though - - take it in to dealer and have them take a look at it since this doesn't sound normal...Hope it works out :cheers:
 

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There is 2 possible explanation that comes to mind:

1. Your clutch is slipping badly. Since you shift around 4k RPM, the clutch will slip at will if your clutch is worn out.

2. You are shifting to agressively and your rear is loosing traction and your DSC is kicking in.

It's easy enough eliminate #2 by just switching DSC off. And for #1, when your car slows down does the engine continues reving? if it is then your clutch is toast.
 
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