Loss of power under hard acceleration

Greg P · 03-07-2009, 12:09 PM

My car has been developing this problem for a while now, but it's seems to be getting worse. Basically, when I'm accelerating hard in 2nd/3rd the engine seems to go through flat spots of power during acceleration. After a second or so the car carries on accelerating. Between 2 and 6k rpm it probably hits 2-3 flat spots.
I've read about possible problems with the fuel pump, but I'm not getting any warning lights or stored faults like other people seem to have had. Of course I'm also worried that at some point the car will lose all power and leave me stranded.

My car is a November 08 M3.

Ideas appreciated.

AW_M3 · 03-07-2009, 03:24 PM

MDM Kicking in ?

arr0gant · 03-07-2009, 04:32 PM

yup, see if it does it wth TC/MDM off.

argonboy · 03-07-2009, 05:48 PM

If traction control kicks in, he would notice the dashboard light. Let's not insult the OP's intelligence, guys.

arr0gant · 03-07-2009, 06:07 PM

Quote:

Originally Posted by argonboy

If traction control kicks in, he would notice the dashboard light. Let's not insult the OP's intelligence, guys.

He asked for idea's, right?

alpine335i · 03-07-2009, 06:10 PM

Maybe your engine was built on a friday?

epoints · 03-07-2009, 10:36 PM

does it feel like the gas is cut off? I just had mine in the shop for 1 month...

ChitownM3 · 03-07-2009, 10:36 PM

Quote:

Originally Posted by argonboy

If traction control kicks in, he would notice the dashboard light. Let's not insult the OP's intelligence, guys.

I don't think it does all the time. I feel the car dog out sometimes when I shift hard and I know its the TC kicking in, although I've never noticed the light.

Greg P · 03-08-2009, 12:52 PM

Quote:

Originally Posted by epoints

does it feel like the gas is cut off? I just had mine in the shop for 1 month...

It does feel like fuel starvation. No flashing dash lights and the problem has only started in the past 6 months (and getting worse).

J08M3 · 03-08-2009, 01:15 PM

Quote:

Originally Posted by argonboy

If traction control kicks in, he would notice the dashboard light. Let's not insult the OP's intelligence, guys.

Light doesn't always come on. I've had this same thing happen and if you try with DSC turned off it never happens. Traction Control doesn't always flash the light.

argonboy · 03-08-2009, 01:45 PM

I guess I never noticed that DSC kicking in and no light. Thanks for the info.

arr0gant · 03-08-2009, 03:50 PM

Quote:

Originally Posted by argonboy

I guess I never noticed that DSC kicking in and no light. Thanks for the info.

If that's what it is, I'm gonna "slap" you!!!

J08M3 · 03-08-2009, 04:00 PM

Try it out. Turn off DSC totally and see if you can get the same symptoms of loss of power.

mkoesel · 03-08-2009, 05:07 PM

Definitely sounds like DSC to me. And I agree it can come on without flashing the light.

camaross305 · 03-08-2009, 05:12 PM

Quote:

Originally Posted by J08M3

Light doesn't always come on. I've had this same thing happen and if you try with DSC turned off it never happens. Traction Control doesn't always flash the light.

Yup started noticing this the other day.... no lights on the dash saying no traction but when i turn DSC completely off the acceleration problem is gone.... I think the MDM is too sensitive sometimes or somtething because with DSC my car barely chirps and i dont know y the MDM is kicking in?

Greg P · 03-09-2009, 04:08 AM

Quote:

Originally Posted by J08M3

Try it out. Turn off DSC totally and see if you can get the same symptoms of loss of power.

Took DSC of last night and it actually seems to be better (could be my imagination though) but it certainly hasn't gone totally.

04S · 03-09-2009, 04:42 AM

Not sure in this little beast you want to be driving around all the time with DSC off. I certainly have had a loss of power with the DSC on without the lights flashing, but it felt to me like it was the car regulating the acceleration rather than an engine fault.

2008e93M3lease · 03-09-2009, 07:53 AM

Hey! The same thing happens to me too! I'll hit the gas and NOTHING happens. Usually right after shifting. It can't be dsc, because I always feel it when the DSC is on. Could it be the locking rear differential (I know nothing about cars) sensing slippage or something?

J08M3 · 03-09-2009, 08:05 AM

Quote:

Originally Posted by 2008e93M3lease

Hey! The same thing happens to me too! I'll hit the gas and NOTHING happens. Usually right after shifting. It can't be dsc, because I always feel it when the DSC is on. Could it be the locking rear differential (I know nothing about cars) sensing slippage or something?

Have you tried to replicate with DSC turned off?

03-07-2009, 12:09 PM	#1
Greg P Private 18 Rep 83 Posts Drives: F82 M4, Elan SE, R8 Spyder Join Date: Oct 2005 Location: Northamptonshire, UK iTrader: (0)	Loss of power under hard acceleration My car has been developing this problem for a while now, but it's seems to be getting worse. Basically, when I'm accelerating hard in 2nd/3rd the engine seems to go through flat spots of power during acceleration. After a second or so the car carries on accelerating. Between 2 and 6k rpm it probably hits 2-3 flat spots. I've read about possible problems with the fuel pump, but I'm not getting any warning lights or stored faults like other people seem to have had. Of course I'm also worried that at some point the car will lose all power and leave me stranded. My car is a November 08 M3. Ideas appreciated.
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03-07-2009, 03:24 PM	#2
AW_M3 ///M 22 Rep 182 Posts Drives: E92 M3 AW/FR Extended Join Date: Mar 2008 Location: Kwt iTrader: (0)	MDM Kicking in ?
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03-07-2009, 04:32 PM	#3
arr0gant Lieutenant 32 Rep 517 Posts Drives: 1996 911 Carrera Cab Join Date: Jun 2008 Location: St. Louis iTrader: (0)	yup, see if it does it wth TC/MDM off. __________________ 1996 911 Carrera Cabriolet 2006 Porsche Cayman S, 2004 M3 Vert, 2008 BMW M3 Sedan, 2001 911 Turbo, 2002 Porsche 911 C4S, 2004 Cadillac CTS-V, Porsche Boxster S
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03-07-2009, 05:48 PM	#4
argonboy First Lieutenant 12 Rep 306 Posts Drives: M3 E92 Space Gray Join Date: Nov 2007 Location: Bucharest, Romania iTrader: (1)	If traction control kicks in, he would notice the dashboard light. Let's not insult the OP's intelligence, guys. __________________
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03-07-2009, 06:10 PM	#6
alpine335i Captain 44 Rep 687 Posts Drives: 08 e92 M3 6MT, 08 e90 328xi Join Date: Nov 2006 Location: Poughkeepsie, NY iTrader: (2)	Maybe your engine was built on a friday? __________________ 2008 Alpine White E92 ///M3
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03-07-2009, 10:36 PM	#7
epoints Private First Class 2 Rep 111 Posts Drives: 550i Join Date: Jul 2008 Location: OC iTrader: (0)	does it feel like the gas is cut off? I just had mine in the shop for 1 month...
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03-08-2009, 01:45 PM	#11
argonboy First Lieutenant 12 Rep 306 Posts Drives: M3 E92 Space Gray Join Date: Nov 2007 Location: Bucharest, Romania iTrader: (1)	I guess I never noticed that DSC kicking in and no light. Thanks for the info. __________________
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03-08-2009, 04:00 PM	#13
J08M3 Major General 287 Rep 6,007 Posts Drives: 2011 M3 COUPE Join Date: May 2008 Location: NEW YORK iTrader: (8)	Try it out. Turn off DSC totally and see if you can get the same symptoms of loss of power. __________________
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03-08-2009, 05:07 PM	#14
mkoesel Moderator 7525 Rep 19,368 Posts Drives: No BMW for now Join Date: Jun 2006 Location: Canton, MI iTrader: (1)	Definitely sounds like DSC to me. And I agree it can come on without flashing the light.
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03-09-2009, 04:42 AM	#17
04S Captain 174 Rep 837 Posts Drives: M4 xDrive, X5 40i and U11 X1 Join Date: Sep 2008 Location: Sydney, Australia iTrader: (0)	Not sure in this little beast you want to be driving around all the time with DSC off. I certainly have had a loss of power with the DSC on without the lights flashing, but it felt to me like it was the car regulating the acceleration rather than an engine fault.
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03-09-2009, 07:53 AM	#18
2008e93M3lease Private First Class 20 Rep 119 Posts Drives: m3 Join Date: Feb 2009 Location: miami, fl iTrader: (0)	Hey! The same thing happens to me too! I'll hit the gas and NOTHING happens. Usually right after shifting. It can't be dsc, because I always feel it when the DSC is on. Could it be the locking rear differential (I know nothing about cars) sensing slippage or something?
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