Slight lag in acceleration @ 3K RMP?

Hawkeye3 · 01-14-2006, 10:44 PM

I think I feel a VERY slight pause around 3100 RMP when accelerating hard 25-30% of the time. Seems like it is most common in the first 5-10 minutes of driving and when I am climbing an incline. Sometimes I think it may be traction control w/o the lamp lighting on the dash. Anyone else run into this problem or am I just crazy?

BMW0 · 01-14-2006, 10:51 PM

It depends if your car is still in the break-in process or not (1250miles till break in period complete).

shoread · 01-15-2006, 06:11 AM

Yes, I percieve my car to be very similar to what you describe.

I have a 325iSE (UK) with manual gearbox, now with 4000 miles.

Initially I thought it was down to the fact that it's not fully run-in, and it has got a bit better, I reckon.

B ut still find that when I accelerate, there's sometimes a slight lull before it picks up again, a bit like turbo-lag even though there is no turbo.

Usually between about 27000 & 32000 rpm.

What car model is yours, and howe many miles have you done?

Pyrat 2 · 01-15-2006, 08:15 AM

Quote:

Originally Posted by Hawkeye3

I think I feel a VERY slight pause around 3100 RMP when accelerating hard 25-30% of the time. Seems like it is most common in the first 5-10 minutes of driving and when I am climbing an incline. Sometimes I think it may be traction control w/o the lamp lighting on the dash. Anyone else run into this problem or am I just crazy?

I haven't noticed at what RPM this happens since when it does happen on my car the pedal is down and I'm looking out and not at the dash. Anyhow the sympton you describe definately happens in my car. Wonder if it has something to do with the 2 stage manifold.

Cory1000 · 01-15-2006, 11:16 AM

got 17k on car and I still have this issue

a burrito · 01-15-2006, 12:12 PM

Quote:

Originally Posted by Cory1000

got 17k on car and I still have this issue

I previously did have this problem but now i dont. First 4k miles i babied it. The next 4k i slowly ran it harder and harder. Till now, i just drive normal. I currently have 11,500 miles.

Hawkeye3 · 01-15-2006, 01:19 PM

Sorry, I left details off first post. My car is a 330i manual with sport & premium. It has over 5K mi and I run it pretty hard every weekday. It is also a pre Sept build, I suspect it may be related to the software of the early cars, but really don't know. At any rate, it seems like something that should not be happening and any ideas re: a fix would be appreciated.

shoread · 01-16-2006, 12:42 PM

My 325i SE is an October build, so if it has the same problem as yous then it isn't as simple as the software version pre/post Sept.

Maybe there is a software bug which existed pre Sept and still exists post Sept, or maybe there's some sensor which can give erroneous readings affecting the ECU.

I think I'm going to get them to have a look at mine.

Perhaps you do the same, and we can compare notes/experiences??

Hawkeye3 · 01-17-2006, 08:34 PM

Shoread,

Sounds good, I need to go in and get a rattle in my B piller fixed as well.

I'll keep you "posted."

carlosng · 01-17-2006, 09:32 PM

It does it on mine in auto mode
buit in d/s or manual mode no problem

Jogger · 01-18-2006, 04:51 AM

I've noticed it as well and I'm driving a manual 325xi with about 4000 miles on it. It seems to happen when I going about 45mph and "step on it" in 3rd or 4th gear, typically when merging on to an expressway. I attribute it to the engine computer's "smart" valve management that decides whether the valves should be partially or fully open. I plan on test driving another 325xi at some point to see if mine's typical.

PittWm · 01-19-2006, 12:08 AM

I have my for about 2 wks, it was a Dec built. I noticed the hesitation first few days, it feels like the limiter kick in at 2k rpm for a second or so.

It now has 268 miles and the lag is gonna. I wondered if it had anything to do with the gas? My lag disappear on my 2nd tank.

F32Fleet · 01-19-2006, 08:01 AM

It could be the VANOS. E90Fleet can shed more light on the subject, but from what I understand is that the VANOS makes an adjustment to provide better performance at rpms 4k+ (maybe 3.5k with your new I6). If you look at dyno's for the E46 you'll see a flat spot round 4k rpms. Probably same with the E90.

Could also be a knock sensor problem. Some E46 ZHP's had a problem where something in the engine was causeing the knock sensor to
"trip" around 4k rpms and thereby retard timing. The fix for the E46 involved reflashing the DME and replacing some obscure part I can't remember.

My $.02

Jogger · 01-19-2006, 08:49 AM

Quote:

Originally Posted by Socom

It could be the VANOS. E90Fleet can shed more light on the subject, but from what I understand is that the VANOS makes an adjustment to provide better performance at rpms 4k+ (maybe 3.5k with your new I6). If you look at dyno's for the E46 you'll see a flat spot round 4k rpms. Probably same with the E90.

Unlike the original poster, I'm actually experiencing my "lag" right around 4000 rpm and it only seems to occur if I make a drastic change in acceleration (i.e. floor it).

wongmb · 03-10-2006, 12:46 PM

I am experiencing something similar (between 3200-3800 rpm). Its quite obvious if I upshift and it just dips to those rpm. There is definitely a lag before it picks up again (like a surge of power as if turbo kicks in.) However it does not happen all the time. Mine is a Jun 05 built and already had the software updated back in Sep.
I already talk to my service technician but he said he has not heard similar complaints so far. He suggest to bring my car in to have a techinician take it out for a test drive.

Driv3r · 03-10-2006, 04:01 PM

I also have a pre sept build 325 and I get the same "lag". ----Try this, go to 2nd gear at around idle speed, then floor it from there. You will notice that there are about 3 sections of power, the bottom(idle-2700),MidRange(2700-4000), and Highrange(4000-6200). Then after 6200 there is a dramatic drop in power all the way till the redline... The 3 sections can be very easily felt. I hope that this is only a software issue..

Sho · 03-10-2006, 04:45 PM

I never pay attention to it, so I guess I don't have it. The car is pre-Sep. built, but I had the software updated in November when it was available. With 8250 miles on the clock now, the car is smoother than before, and seems like the power picks up very well from 2700 rpm all the way to around 6300 rpm. An oil change may be helpful.

Hawkeye3 · 03-10-2006, 07:09 PM

I had the software updated about a month ago and it seems like it is gone or at least it happens less frequently. Hard to say for sure as it was never obvious. I'll start paying closer attention and report back. I guess the fact that I'm not sure if it's improved means it was never that bad.

01-14-2006, 10:44 PM	#1
Hawkeye3 Private 1 Rep 56 Posts Drives: 06 330i, sport Join Date: Nov 2005 Location: Cincinnati, OH iTrader: (0) Garage List 2006 330i [0.00]	Slight lag in acceleration @ 3K RMP? I think I feel a VERY slight pause around 3100 RMP when accelerating hard 25-30% of the time. Seems like it is most common in the first 5-10 minutes of driving and when I am climbing an incline. Sometimes I think it may be traction control w/o the lamp lighting on the dash. Anyone else run into this problem or am I just crazy?
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01-14-2006, 10:51 PM	#2
BMW0 Colonel 241 Rep 2,059 Posts Drives: AW E90 330i Join Date: Nov 2005 Location: Spokane, WA iTrader: (0) Garage List 2006 330i [0.00]	It depends if your car is still in the break-in process or not (1250miles till break in period complete). __________________ 330i 6MT l 255 HP @ 5900 rpm 214 lb-ft Torque @ 3500 rpm l Alpine White l Beige l Aluminum l ZSP l 494 l PDC "Freude am Fahren" = "Joy to Drive"
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01-15-2006, 06:11 AM	#3
shoread Enlisted Member 3 Rep 44 Posts Drives: E90 325i SE Saloon Join Date: Nov 2005 Location: Bristol, GB iTrader: (0)	Yes, I percieve my car to be very similar to what you describe. I have a 325iSE (UK) with manual gearbox, now with 4000 miles. Initially I thought it was down to the fact that it's not fully run-in, and it has got a bit better, I reckon. B ut still find that when I accelerate, there's sometimes a slight lull before it picks up again, a bit like turbo-lag even though there is no turbo. Usually between about 27000 & 32000 rpm. What car model is yours, and howe many miles have you done?
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01-15-2006, 11:16 AM	#5
Cory1000 God 32 Rep 320 Posts Drives: 2006 325i Join Date: May 2005 Location: NJ iTrader: (1)	got 17k on car and I still have this issue
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01-15-2006, 01:19 PM	#7
Hawkeye3 Private 1 Rep 56 Posts Drives: 06 330i, sport Join Date: Nov 2005 Location: Cincinnati, OH iTrader: (0) Garage List 2006 330i [0.00]	Sorry, I left details off first post. My car is a 330i manual with sport & premium. It has over 5K mi and I run it pretty hard every weekday. It is also a pre Sept build, I suspect it may be related to the software of the early cars, but really don't know. At any rate, it seems like something that should not be happening and any ideas re: a fix would be appreciated.
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01-16-2006, 12:42 PM	#8
shoread Enlisted Member 3 Rep 44 Posts Drives: E90 325i SE Saloon Join Date: Nov 2005 Location: Bristol, GB iTrader: (0)	My 325i SE is an October build, so if it has the same problem as yous then it isn't as simple as the software version pre/post Sept. Maybe there is a software bug which existed pre Sept and still exists post Sept, or maybe there's some sensor which can give erroneous readings affecting the ECU. I think I'm going to get them to have a look at mine. Perhaps you do the same, and we can compare notes/experiences??
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01-17-2006, 08:34 PM	#9
Hawkeye3 Private 1 Rep 56 Posts Drives: 06 330i, sport Join Date: Nov 2005 Location: Cincinnati, OH iTrader: (0) Garage List 2006 330i [0.00]	Shoread, Sounds good, I need to go in and get a rattle in my B piller fixed as well. I'll keep you "posted."
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01-17-2006, 09:32 PM	#10
carlosng CARLUVKRIS 1 Rep 42 Posts Drives: 2019 M240I m PERFORMANCE Join Date: Oct 2005 Location: Canada iTrader: (0) Garage List 2006 330I [0.00] 2006 330i [0.00] 2006 330i [0.00]	It does it on mine in auto mode buit in d/s or manual mode no problem __________________ 2006 330I H & R sport /rear lip spoiler/19" wheels 235f265r :rocks: :
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01-18-2006, 04:51 AM	#11
Jogger New Member 0 Rep 10 Posts Drives: e90 325xi BR Join Date: Oct 2005 Location: Ann Arbor, MI iTrader: (0)	I've noticed it as well and I'm driving a manual 325xi with about 4000 miles on it. It seems to happen when I going about 45mph and "step on it" in 3rd or 4th gear, typically when merging on to an expressway. I attribute it to the engine computer's "smart" valve management that decides whether the valves should be partially or fully open. I plan on test driving another 325xi at some point to see if mine's typical.
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01-19-2006, 12:08 AM	#12
PittWm Second Lieutenant 7 Rep 209 Posts Drives: 06 330i SP pack, Prem pack, CW Join Date: Jan 2006 Location: Paducah KY, USA iTrader: (0)	I have my for about 2 wks, it was a Dec built. I noticed the hesitation first few days, it feels like the limiter kick in at 2k rpm for a second or so. It now has 268 miles and the lag is gonna. I wondered if it had anything to do with the gas? My lag disappear on my 2nd tank.
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01-19-2006, 08:01 AM	#13
F32Fleet Lieutenant General 3637 Rep 10,394 Posts Drives: 2015 435i Join Date: May 2005 Location: Southeastern US iTrader: (0)	It could be the VANOS. E90Fleet can shed more light on the subject, but from what I understand is that the VANOS makes an adjustment to provide better performance at rpms 4k+ (maybe 3.5k with your new I6). If you look at dyno's for the E46 you'll see a flat spot round 4k rpms. Probably same with the E90. Could also be a knock sensor problem. Some E46 ZHP's had a problem where something in the engine was causeing the knock sensor to "trip" around 4k rpms and thereby retard timing. The fix for the E46 involved reflashing the DME and replacing some obscure part I can't remember. My $.02
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03-10-2006, 12:46 PM	#15
wongmb Private 4 Rep 78 Posts Drives: 2006 325i SP Join Date: Sep 2005 Location: Markham, Ontario iTrader: (0)	I am experiencing something similar (between 3200-3800 rpm). Its quite obvious if I upshift and it just dips to those rpm. There is definitely a lag before it picks up again (like a surge of power as if turbo kicks in.) However it does not happen all the time. Mine is a Jun 05 built and already had the software updated back in Sep. I already talk to my service technician but he said he has not heard similar complaints so far. He suggest to bring my car in to have a techinician take it out for a test drive.
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03-10-2006, 04:01 PM	#16
Driv3r Colonel 178 Rep 2,355 Posts Drives: 2006 E46 M3 ZCP Join Date: May 2005 Location: Miami Beach, FL iTrader: (8) Garage List 2006 325i [0.00]	I also have a pre sept build 325 and I get the same "lag". ----Try this, go to 2nd gear at around idle speed, then floor it from there. You will notice that there are about 3 sections of power, the bottom(idle-2700),MidRange(2700-4000), and Highrange(4000-6200). Then after 6200 there is a dramatic drop in power all the way till the redline... The 3 sections can be very easily felt. I hope that this is only a software issue.. __________________ 2006 E46 M3 ZCP 6SPD-Interlagos Blue - 6SPD - SSK - AA Headers -AA Tune - Navigation w/ Splashscreen Mod - 3M Crystalline Series 60 - Carbon Splitters - Swissvax Treated - Bridgestone 2012 Yamaha FZ8 - Matte Black/Grey - Michelin Pilot Pure 2CT - Vortex Rear Sets - Yoshimura R-77D & Fender Delete - Spectro Race Oil - GP Reverse Shifting
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03-10-2006, 04:45 PM	#17
Sho Lieutenant 35 Rep 574 Posts Drives: E90 325i 6-speed Join Date: May 2005 Location: WA iTrader: (0)	I never pay attention to it, so I guess I don't have it. The car is pre-Sep. built, but I had the software updated in November when it was available. With 8250 miles on the clock now, the car is smoother than before, and seems like the power picks up very well from 2700 rpm all the way to around 6300 rpm. An oil change may be helpful. __________________ 2006 325i Sport - SSR GT7, Euro tails, Rogue Ikon muffler/w custom 3.5" piping, Painted OEM Splitters 2005 Toyota Matrix - Commuter
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03-10-2006, 07:09 PM	#18
Hawkeye3 Private 1 Rep 56 Posts Drives: 06 330i, sport Join Date: Nov 2005 Location: Cincinnati, OH iTrader: (0) Garage List 2006 330i [0.00]	I had the software updated about a month ago and it seems like it is gone or at least it happens less frequently. Hard to say for sure as it was never obvious. I'll start paying closer attention and report back. I guess the fact that I'm not sure if it's improved means it was never that bad.
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