car jerk/idle jerk/accerleration/jerk...how big an issue is this?
05-20-2009, 11:47 PM
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My Ride: BMW 530d M Sport (58) LCI
Originally Posted by alphaquhp' post='884365' date='May 20 2009, 11:42 AM
Hey all,
I'm seriously looking into getting a 545i, or at least a 530i ('04 or '05). Most likely it will be an auto tranny. But I've been reading a lot on this "idle jerk" or "acceleration jerk" or some kind of car jerk on these 5 series. I've test driven an 04 545i and loved it and did not feel this 'jerk' during the test drive, but I didn't know about this issue then. How 'serious' of an issue is this to those of you who experience(d) this?
Does a manual transmission experience this?
Currently have a 325i and would love to get into a 545i.
Thanks all for the help.
I'm seriously looking into getting a 545i, or at least a 530i ('04 or '05). Most likely it will be an auto tranny. But I've been reading a lot on this "idle jerk" or "acceleration jerk" or some kind of car jerk on these 5 series. I've test driven an 04 545i and loved it and did not feel this 'jerk' during the test drive, but I didn't know about this issue then. How 'serious' of an issue is this to those of you who experience(d) this?
Does a manual transmission experience this?
Currently have a 325i and would love to get into a 545i.
Thanks all for the help.
It's caught me and family out the first time i did it, but as it's my third BMW auto kindah use to it. So no biggie. I don't think i could go back to driving a manual
With the steptronic and when you want to take it easy the lovely auto why bother.
05-20-2009, 11:49 PM
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My Ride: BMW 530d M Sport (58) LCI
Originally Posted by gwf545' post='885249' date='May 21 2009, 01:53 AM
Annoying yes. Avoidable, yes. Serious, no. I would not let this issue stop me from buying a 545i. If you drive the Steptronic in manual mode, you avoid it alltogether. It's easiest to produce in full automatic "D" mode, but you can avoid it by paying attentiion to what gear you are in and not accelerating when the tranmission is shifting or about to shift from 2 to 1. It seems to be a problem where the engine and transmission electronics get out of sync with the actual tranmission mechanical state.
05-20-2009, 11:51 PM
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My Ride: BMW 530d M Sport (58) LCI
Originally Posted by flyingpuck' post='885224' date='May 21 2009, 01:36 AM
You are experiencing "Transmission Slam", it is a known issue at BMW, it can be addressed by a software upgrade or if persistent, with a transmission replacement! 
So get yourself to the dealer!! 
So get yourself to the dealer!! Do you know if the software upgrade is already on the newer cars? Mines is 6 months old, just wondering if i need to go to the dealers/stealers
05-21-2009, 09:51 AM
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Mines is the 530d M Sport fairly new (6 months old) and i do have to say there is a jerk when i put my foot down. While i'm crusing say around 30 mph and decide to go a little faster to get the lights, so i put my foot down what will happen is a little pause and then a jerk as the power comes wooshing by.
It's caught me and family out the first time i did it, but as it's my third BMW auto kindah use to it. So no biggie. I don't think i could go back to driving a manual With the steptronic and when you want to take it easy the lovely auto why bother.
It's caught me and family out the first time i did it, but as it's my third BMW auto kindah use to it. So no biggie. I don't think i could go back to driving a manual
With the steptronic and when you want to take it easy the lovely auto why bother.Thanks everyone for the feedback.
05-22-2009, 05:49 AM
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My Ride: 2005 545i Black on Black, Auto, Premium, Sport, Dynamic Drive, Nav
Does anyone know if there is a SIB for the software upgrade? I find that printing it out and taking it to the dealer helps with quicker problem resolution.
05-22-2009, 06:44 AM
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Originally Posted by NoName545i' post='885035' date='May 20 2009, 09:06 PM
i had the software update regarding this issue.
NO MORE JERKING!!!
NO MORE JERKING!!!
The issue seems to be around acceleration from stop or whilst cruising, where it holds for a sec or two and then goes with a jerk. I thought it would be ok, but finding it annoying now, especially as it scares the bejesus out of the passenger.
05-22-2009, 09:23 AM
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My wife complains about it on her 550i and so does her friend down the street who has an 05 545i. My wife wants to know how come it doesn't do it when I drive her car. I told her that what seems to happen is: when you give it gas it takes off real slow, so you give it more gas and that in turn, due to the torque control management in the computer, it realizes that you want more acceleration power so it gives you more power - in a real non-linear fashion. I noticed that there is "sweet spot" where you can take off smoothly and once you get some speed off the line you can give it more gas and it'll react more smoothly.
I don't know why they designed the calibrations like this, but then again, this car is a lot more complicated than it needs to be, (iDrive).
I asked my dealer at Three Stooges BMW in Monrovia, California and they acted like they knew absolutely nothing about the driveability issues that have been brought up here in the forums. I did talk to one of the mechanics (excuse me, technicians) about the issue and he said that he had a custom tune done on his computer which eliminated any of the jerkiness and make the acceleration more linear. But he advised me against it since my car in under warranty and BMW would not honor any drivetrain warranty work if they did a check and found out I was using a non-BMW authorized program. I can't take that chance.
I don't know why they designed the calibrations like this, but then again, this car is a lot more complicated than it needs to be, (iDrive).
I asked my dealer at Three Stooges BMW in Monrovia, California and they acted like they knew absolutely nothing about the driveability issues that have been brought up here in the forums. I did talk to one of the mechanics (excuse me, technicians) about the issue and he said that he had a custom tune done on his computer which eliminated any of the jerkiness and make the acceleration more linear. But he advised me against it since my car in under warranty and BMW would not honor any drivetrain warranty work if they did a check and found out I was using a non-BMW authorized program. I can't take that chance.
05-22-2009, 01:44 PM
#19
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Originally Posted by Bawa' post='886503' date='May 22 2009, 06:49 AM
Does anyone know if there is a SIB for the software upgrade? I find that printing it out and taking it to the dealer helps with quicker problem resolution.
I had it done to my car. Drives more spirited, like they made the shift points more aggressive-- but low speed shudder is still there when cold. How serious is the low speed shudder? Not sure. If sign of failing tranny, then really serious. If just a quirk of car that is annoying and can be avoided by driving in sport until it warms up-- no big deal. The 2-1 slam, however, can be downright scary and is, IMHO, unacceptable.
I read this in another thread which frankly makes sense to me:
"The main service mechanic rode along with me today and about 60 seconds into our ride I began to explain the grumbling sound with the low RPMs and he said 'I already know what it is and it's not the transmission.' Then I was expecting some answer like Click and Clack that it was the driver who's the problem!
Turns out for those of us with the automatic transmission, on a long coast or idle through traffic the TCU/TCM tries to maximize the fuel efficiency. It does this by shifting to a high gear (4th gear in the e60) and then applies a lock-up torque converter. Read the wikipedia article - it sums up my experience.
The mechanic said that if I wanted to work around the problem, shift into manual or sport mode to prevent the TCU/TCM from trying to conserve fuel."
http://forums.e60.net/index.php?showtopic=...ansmission+lock
05-22-2009, 02:04 PM
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I would like to QUOTE from this post .. which to date seems to give the best plausible explanation of this age old issue. This one seems to have come directly from the horse's mouth i.e. ZF itself. In essence .. no matter what .. you will experience "slams" due to a root cause as the above post explains (the car is tuned for economy in "D" mode). I repeat .. you will have to either use DS or manual mode to avoid it. Though the post does seem old .. there seems to be a lot of credence to the root cause ...
Link: http://forums.e60.net/index.php?showtopic=...20park&st=0
I would like to QUOTE from this post .. which to date seems to give the best plausible explanation of this age old issue. This one seems to have come directly from the horse's mouth i.e. ZF itself. In essence .. no matter what .. you will experience "slams" due to a root cause as the above post explains (the car is tuned for economy in "D" mode). I repeat .. you will have to either use DS or manual mode to avoid it. Though the post does seem old .. there seems to be a lot of credence to the root cause ...
Link: http://forums.e60.net/index.php?showtopic=...20park&st=0
This morning I took my car out with an engineer from ZF (who make the transmission) heis seconded to BMW UK to troubleshoot transmission issues.
He connected up a diagnostic kit to the plug in the drivers footwell to monitor the tranny whilst I drove.
We were able to reproduce the 'slam' to order by slowing to about 3 mph gradually and then just before coming to a halt, accelerating fairly briskly.
Almost every time the revs went up and after a delay the car picked up the drive and shot forward.
We could also reproduce another behaviour. When going down a steep hill, causing acceleration due to gravity with foot off throttle, touch and release the brakes. The car downshifts 2 gears, giving high revs, then accelerate again and you get quite harsh upshifts.
His explanation of the 'slam' was as follows.
The transmission is working 'normally'. The shift point is set up with a stop/go system so that as you drive in traffic the car does not drop below 2nd gear. This enables a smooth progress without unnessecary shifts into 1st. The normal pick up with gentle acceleration is easily achieved in 2nd.
The consequence of this set up is that if you suddenly ask the car for high acceleration levels it detects that it cannot achieve this in 2nd and selects 1st with a consequent delay. This has been measured by ZF as about 0.75 seconds, though he accepted it often feels a lot longer.
I pointed out that when pulling out into traffic which is travelling at 50mph, on oncoming car travels at 75 feet per second, so 0.75 of a second delay is not good news.
The only solution to the issue is to reset the shift points so that the car always selects 1st when the speed drops, this however would mean a huge number of 1>2 > 1 shifts in stop start traffic giving a poor ride and the risk of harsh low speed shifts.
The problem is exacerbated in larger diesel engines due to the high torque and the slight turbo delay.
The same process is present in petrol engines but is felt much less due to the faster response of the engine to the throttle and the lower torque at lower revs. hence it is often viewed as a diesel only problem. The greater the torque the more noticeable the behaviour. This explains why the 530D and 545i and up raise complaints whilst the 520i and 525D seem less prone.
The only way to mitigate the issue is to select DS which forces selection of 1st at low speeds, but be aware that you will feel harsher 2>1 shifts in traffic.
Every 5 series 'suffers' as do Jaguars, Audi's and others but due to different driving styles and road environments, some drivers will notice it more than others. It is especially noticeable if you are a frequent user of roundabouts where you often approach at a very slow speed the accelerate without coming to a full halt.
The downhill behaviour is due to the software detecting acceleration whilst also detecting a braking signal. It interprets this as brake failure and, as a safety system, initiates downshifts to provide engine braking.
The bottom line is that currently there is no 'solution' to the 'slam' issue, there is no software update beyond 17.10 that will have any direct effect on the tranny behaviour, though he does not rule out that at some time in the future there may be changes. There is nothing currently on the radar.
He connected up a diagnostic kit to the plug in the drivers footwell to monitor the tranny whilst I drove.
We were able to reproduce the 'slam' to order by slowing to about 3 mph gradually and then just before coming to a halt, accelerating fairly briskly.
Almost every time the revs went up and after a delay the car picked up the drive and shot forward.
We could also reproduce another behaviour. When going down a steep hill, causing acceleration due to gravity with foot off throttle, touch and release the brakes. The car downshifts 2 gears, giving high revs, then accelerate again and you get quite harsh upshifts.
His explanation of the 'slam' was as follows.
The transmission is working 'normally'. The shift point is set up with a stop/go system so that as you drive in traffic the car does not drop below 2nd gear. This enables a smooth progress without unnessecary shifts into 1st. The normal pick up with gentle acceleration is easily achieved in 2nd.
The consequence of this set up is that if you suddenly ask the car for high acceleration levels it detects that it cannot achieve this in 2nd and selects 1st with a consequent delay. This has been measured by ZF as about 0.75 seconds, though he accepted it often feels a lot longer.
I pointed out that when pulling out into traffic which is travelling at 50mph, on oncoming car travels at 75 feet per second, so 0.75 of a second delay is not good news.
The only solution to the issue is to reset the shift points so that the car always selects 1st when the speed drops, this however would mean a huge number of 1>2 > 1 shifts in stop start traffic giving a poor ride and the risk of harsh low speed shifts.
The problem is exacerbated in larger diesel engines due to the high torque and the slight turbo delay.
The same process is present in petrol engines but is felt much less due to the faster response of the engine to the throttle and the lower torque at lower revs. hence it is often viewed as a diesel only problem. The greater the torque the more noticeable the behaviour. This explains why the 530D and 545i and up raise complaints whilst the 520i and 525D seem less prone.
The only way to mitigate the issue is to select DS which forces selection of 1st at low speeds, but be aware that you will feel harsher 2>1 shifts in traffic.
Every 5 series 'suffers' as do Jaguars, Audi's and others but due to different driving styles and road environments, some drivers will notice it more than others. It is especially noticeable if you are a frequent user of roundabouts where you often approach at a very slow speed the accelerate without coming to a full halt.
The downhill behaviour is due to the software detecting acceleration whilst also detecting a braking signal. It interprets this as brake failure and, as a safety system, initiates downshifts to provide engine braking.
The bottom line is that currently there is no 'solution' to the 'slam' issue, there is no software update beyond 17.10 that will have any direct effect on the tranny behaviour, though he does not rule out that at some time in the future there may be changes. There is nothing currently on the radar.
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