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View Full Version : Jerky SMG when cold..?


wood634
Fri, Jan-21-2005, 10:09:26 PM
Hi all - first post from a new Jan'04 M3 SMG II Cabriolet owner. This thing rocks! Well mannered for normal driving and balls-out performance when desired. It scares my wife something rotten! Brilliant.

However I have a problem and I am unsure if I am being brushed off by my dealer - so I thought I would ask you lot of nice people... I searched the forum first and could find nothing related...

When I start my car from cold it fires up fine, however when moving away in first and second gears the transmission is VERY jerky (similar to having the sport button engaged in very slow moving traffic). Easing off the the throttle and reapplying pressure normally aleviates the problem. Automatic or manual mode exhibit the same behavior. I normally drive in mode 2 in both auto and manual (upping the selection when I want to play). The behaviour disappears after a short time - usually less than a mile...

The problem only ever occurs on cold and damp mornings (by cold i mean less than 5 degrees Celcius - so it is not a frosty morning or anything). My dealer tells me it is a characteristic of the SMG to be jerky when cold. Jerky I can handle, whiplash however is something else...

I took the car into the dealership and they applied a SMG factory fix for the Change Control unit - it did not resolve this particular problem but it certainly shifts a lot better in modes 4 and 5 now!

Any advice would be greatly appreciated.

Regards

Woody

Will Pwr
Fri, Jan-21-2005, 10:46:27 PM
Not saying that its normal or its "just that way", but most all cars upon cold start have a slightly different idle/rpm characteristic when its warming up. Basically upon a cold start up, the ECU has the motor idle at a slight higher rpm, than when at full operating temp, to aid in the heating up of the catalytic convertors (for emmissions purposes). This in-turn can cause slight roughness in driving for a few minutes. This is more noticable in computer controlled transmissions.

I dont really have a solution or rememdy, but I can tell you that you can/will adjust to it and it will become unnoticable in a short period of time. I dont have any issues with it now, but I did notice it right when I got the car. hope that my $0.02 helps somehow

patty
Fri, Jan-21-2005, 10:54:04 PM
I've had that "problem" as of late. It's usually insignificant enough to not be bothersome, but I know what you mean sometimes when it's just after start up and VERY cold. I wouldn't worry about it.

jimmie48
Fri, Jan-21-2005, 11:30:56 PM
Yep had this. The way the weather fluctuates here in Dallas kills me, and my M doesnt like it much either. Really tempermental when it is really cold and has been sitting all night in it as well. Like you said, I wouldnt worry about something that usually goes away after a few miles, esp once your yellow tach lights go out. Mine usually goes away as well. Tough not to look like an idiot though sometimes when it does that :banghead:

flabmaster
Sat, Jan-22-2005, 12:27:59 AM
I come from a cold area and I can say I've had the jerky cold starts as well. Just keep playing with the throttle and you'll get used to curtailing it. Was the recall that the dealer did the software update or was it the pressure unit recall (do 04's even have the pressure unit recall?)
I normally drive in mode 2 in both auto and manual
You've probably had your M3 long enough to know the idiosynchrasis and to be able to drive smoothly in all the modes but I have just a bit of advice. Most guys, including myself, drive around in mode 4. Modes 1-3 are slow, "comfort" modes where the car will slip the clutch more, thus wearing out the clutch more than the higher modes. Modes 5 and 6 are really aggressive modes where the car will slip the clutch less, saving clutch wear, but they are harder on the drivetrain since they are so fast. Mode 4 seems to be the best balance. By no means am I trying to tell you how to drive your car - to each his own - I'm just trying to offer a little technical insight since I'm not sure what your knowledge of the car is.
-Dave

Thrill
Sat, Jan-22-2005, 12:35:45 AM
SMG is close to a full race tranny so it can be a little temperamental until itís up to operating temperature. You won't even notice after awhile. These are just some trade offs you have to get a trans that will shift like and do what this one will.

Alemania
Sat, Jan-22-2005, 01:31:03 AM
probably nothing to worry about.... but please be aware that there is an open recall for SMG reprogramming for 04's,(nothing related to the bearing rod recall for 02's) which may or may not have anything to do with your symptoms....
Make sure you call BMW NA give them your VIN and they'll you if your car needs the update....
The dealer won't tell you, only because I am curious and called BMW did they tell me about the recall....

khanyam3
Sat, Jan-22-2005, 01:48:02 AM
I dont think you have anything to worry about. It's just a matter of the car's operating temperature, the cold....once it's fully warmed up.....regardless what mode you're in you should be able to get silky smooth shifts when driving smg properly.

ggs
Sat, Jan-22-2005, 08:16:12 PM
Funny, I haven't noticed it, even in -5 degree (F) weather. Maybe you just get used to it over time. I drive in S5 mode all the time, that may have something to do with it as well.

wood634
Thu, Jan-27-2005, 09:25:19 PM
Hi Guys,

Thanks for your input on this. I guess like the dealer stated it is just a characteristic when cold. Not relally a problem - just an irritation in a car costing this much cash.

The plus side is that it does go like stink and handle like it is on rails - so it is not all bad... :-)

With regards to the drivelogic setting I leave it in 2 most of the time as most of my driving is around town and I prefer the softer starts and changes of gear in that mode. Mode 4 and 5 is for when the wife and kids are at home....

Thanks for your input. With regards to whether the smg recall was a hardware or software thing I shall have to enquire for you. The car is back in on the 5th Feb for another niggle so I will find out then 4 you all.

Alemania - calling BMW NA is probably a waste of time as my car is a UK car..?

Cheers for the feedback,

Keith

NetBoy
Thu, Jan-27-2005, 09:57:11 PM
you mention whiplash. is it really bad where the whole cars bucks really hard back and forth ? if yes then it's DIO

But if it stutters and clunks when slowing down in 1st or 2nd then thats OK when the engine is really cold. I see a big difference starting in cold vs mild mornings

wood634
Wed, Feb-09-2005, 10:05:49 PM
In response to your comments the recall was a physicall issue under the bonnet. Apparently on the SMG Controller there are 2 wires reversed which cause the severe lumpiness I was experiencing.

I have induced the jumpiness on occassions when it is cold, so I suspect that the issue was probably me all the time! I have caught my foot rocking back and fortyh on a couple of occasions when the car is kangarooing around...

Getting the knack of it now though!

Grimm333
Wed, Feb-09-2005, 11:43:54 PM
glad to hear you got it checked out...mine does the same...you really want to let that oil temp warm up to a moderate level before getting on it..meaning drive conservatively for about 10-15 after starting...

DaBean
Thu, Feb-10-2005, 03:05:47 AM
I dont think you have anything to worry about. It's just a matter of the car's operating temperature, the cold....once it's fully warmed up.....regardless what mode you're in you should be able to get silky smooth shifts when driving smg properly.

Sorry... slightly OT.. but it says in your sig you have SMG3!?!?! I think you mean SMGII, OR you have the very first SMGIII!!!!!!

GHOSTRIDER
Thu, Feb-10-2005, 05:02:09 AM
This is found in all SMG cars. Don't fret over it. Just know you aren't the only one dealing with it. Like you say it goes away after it reaches normal operating temp withina few miles. If you desire more info on it search for "bucking" if should turn up more threads.