Jerking Car... sometimes... what's wrong?

[LoverofCar]

If is misfire...Misfire can also due to plug cable..but don't change everything at one go..change the cheapest part first so you can isolate the part with problem..

[Ithunk]

from my experience bmw coupes should drive smoothly....was offered a drive by a dealer

 

anyway how is the driving style when u got the vehicle....

 

if it happens when u got it u can go the agent or a bmw workshop to check it out

[Jim]

Could be a dirty throttle body. At least that's what my mech tell me for my car when it shudders on move off and stopping, but I am too cheapskate to pay to clean it, and it went away after my last oil change which also included changing spark plugs and transmission fluid. My car is not BMW though.

[Whatisthis04]

To TS, go get the ATF chng and see if u still encounter the jerk...

 

I don't tink it's the plugs.....

[Thaiyotakamli]

maybe can ask the AD to reset the ICU or maybe due to spark problem, as said by bros here, WORST COME TO WORST GEARBOX PROBLEM!

Edited July 17, 2011 by Thaiyotakamli

[Pjlee25]

Thanks for the interests and replies. Really appreciate the insights gathered.

Let me first provide an update and sum up the situation with your kind inputs. :)

 

Other than the automatic "drive" mode, my ride comes with an automatic "drive-Sports" mode, as well as the steptronic manual mode.

 

I tried the "Sports" mode. I noticed that the rev is higher, and the RPM was never dropped below 2000. The gear change was smooth and there was no jerking. This mode of driving will drive the fuel consumption up though.

 

Back to the problem, as it happens only in the normal "drive" mode, the shuddering happens when the RPM is around 1300-1500. I guess it is a case of low RPM on a higher-than-required gear.

 

Now that it works well on the Sports mode, but not that well on the Drive mode. I would think that there is no problem with the plugs, plug cables, engine and gear box? I would like to hear that the problem is caused by dirty throttle body or maybe the reset of the ECU.

 

Correct me if my deduction is wrong, mates.

[Notsogoodman]

bro, try the BMW-SG forum...

http://www.bmw-sg.com/forums/

[Pjlee25]

Thanks! Will check it out.

[JonEthan]

had this problem before. it was due to a leak (cut) on the spark plug cable. Just changed the cable and everything was ok.

 

[Contax]

clean your throttle body and sensor due carbon built up over time without spirited driving.

[5936]

This is also possible.

[Jolie888]

If your 320i is the E46 (and earlier) model, using the M52B22 (2.2L IL-6) engine, that block is known to have some interface 'mis-givings' with the Steptronic gearbox. Many owners had sensed some form of hesitation, vibrations even, upon normal acceleration from stationary in Auto mode.

 

But if your 320i is the E90 current model, post M54 engines ... the current ones being the N-series with Valvetronic, then I'd suggest that you go back to PML to have the AD's workshop test and provide a cylinder-by-cylinder combustion-cycle profile report. This would usually show where mis-firing could have happened, on which cylinder, due likely to a mis-timed follower-cam profile, that may only require the Valvetronic EU to be re-flashed, or in the worst case, the whole Valvetronic stepper motor to be replaced.

 

[Subutai]

Petrol filter?

 

Happened to my previous ride. Changed petrol filter after using 30k and problem was solved.

[Throttle2]

Hhhmm,....let me see, I think you can solve your problem by getting a 325i....heh heh....dont hit me, joking only

Edited July 18, 2011 by Throttle2

[Gendut]

Hi,

 

I've been on the road for 10 years...

 

Hmmm

 

Without a history of what has been done to the car, its diff to diagnose.

 

Only way out is by trial and error. But I would go and check the injectors first because it sounds like its not getting enough fuel at low cycles.

 

OBDII would also help. Good luck.

[Pjlee25]

If your 320i is the E46 (and earlier) model, using the M52B22 (2.2L IL-6) engine, that block is known to have some interface 'mis-givings' with the Steptronic gearbox. Many owners had sensed some form of hesitation, vibrations even, upon normal acceleration from stationary in Auto mode.

 

But if your 320i is the E90 current model, post M54 engines ... the current ones being the N-series with Valvetronic, then I'd suggest that you go back to PML to have the AD's workshop test and provide a cylinder-by-cylinder combustion-cycle profile report. This would usually show where mis-firing could have happened, on which cylinder, due likely to a mis-timed follower-cam profile, that may only require the Valvetronic EU to be re-flashed, or in the worst case, the whole Valvetronic stepper motor to be replaced.

 

Mine is the e90 model and yes, I think that cylinder check would be a good starting point. Thanks for the info. Really praying that it's not the worse case scenario that you have painted. :)

[Pjlee25]

Hmmm

 

Without a history of what has been done to the car, its diff to diagnose.

 

Only way out is by trial and error. But I would go and check the injectors first because it sounds like its not getting enough fuel at low cycles.

 

OBDII would also help. Good luck.

 

Thanks, Gendut. Really hope to get rid of this problem.

[Pjlee25]

Hhhmm,....let me see, I think you can solve your problem by getting a 325i....heh heh....dont hit me, joking only

 

Hee hee... Throttle, that's an ingenious way out! Maybe 5 years later!