harsh idle in moarnings

AKbmw · 03-09-2009, 05:58 PM

i just got back car back from the dealership because of a bad fuel pump. this morning (two days after the i got it back) when i started my car it started as soon as i pushed the button (unlike with a bad fuel pump there is a long crank) but when i was idling the car was shaking and acting weird, then i see the yellow half engine light or whatever. As i let it sit for 2 minutes or so, it went away and it was all good. i dont know why it did this as i just got it back from the dealer. what could this be?

Note: i have had a Jb3 in the car before i took it to the dealer and also a BMS dual cone intake, and removed my secondary cats. right now i dont have the JB3 in the car (when the harsh idle happened)

what could it be and what should i do? thanks!

OpenFlash · 03-09-2009, 06:01 PM

Do you still have the rough idle? Every time you start the car?

AKbmw · 03-09-2009, 06:06 PM

Quote:

Originally Posted by shiv@vishnu

Do you still have the rough idle? Every time you start the car?

well, today was the 1st day i noticed it after i got my fuel pump replaced, i started the car again after my school and it was fine, its just in the mornings and when it was cold.

OpenFlash · 03-09-2009, 06:08 PM

Quote:

Originally Posted by AKbmw

well, today was the 1st day i noticed it after i got my fuel pump replaced, i started the car again after my school and it was fine, its just in the mornings and when it was cold.

Best thing would be to take it to the dealer again. Let them keep it overnight so they can start it up in the morning and see for themself. I would definitely take/keep the Jb3 out if I were you.

Shiv

AKbmw · 03-09-2009, 06:24 PM

Quote:

Originally Posted by shiv@vishnu

Best thing would be to take it to the dealer again. Let them keep it overnight so they can start it up in the morning and see for themself. I would definitely take/keep the Jb3 out if I were you.

Shiv

i have had the jb3 in for a LONG time with no problems, but i probobally will take it to the dealer if it continues.

RambleJ · 03-09-2009, 06:39 PM

If you have long cranks and a rough idle, it sounds like it may be another hpfp failure! I just started getting long cranks again yesterday, if this end up being a hpfp failure, it will be my third hpfp replacement

Kbueno · 03-09-2009, 06:49 PM

Also could be sparkplugs..it seems they go out over 15k and develop a miss at idle.

AKbmw · 03-09-2009, 07:09 PM

Quote:

Originally Posted by 335lvr

Also could be sparkplugs..it seems they go out over 15k and develop a miss at idle.

thats what im thinking, wouldnt the dealer see that i had a bad spark plug when they had it like 2 days ago when they replaced my hpfp

Kbueno · 03-09-2009, 08:16 PM

Quote:

Originally Posted by AKbmw

thats what im thinking, wouldnt the dealer see that i had a bad spark plug when they had it like 2 days ago when they replaced my hpfp

Doubtful, although you'd think they would notice during a test drive.

tek818 · 03-09-2009, 09:07 PM

Quote:

Originally Posted by 335lvr

Also could be sparkplugs..it seems they go out over 15k and develop a miss at idle.

+1 I just started having the same problems. Got misfire codes along with a limp mode and SES light.

OpenFlash · 03-09-2009, 09:12 PM

Bad plugs/misfire will cause a SES light and P030x codes since misfire is emissions/obd related. A half engine light (with no accompanying SES light) would indicate something else. Fuel pump or failed o2 sensor seem to be the most likely, imho.

Shiv

tek818 · 03-10-2009, 02:12 AM

Quote:

Originally Posted by shiv@vishnu

Bad plugs/misfire will cause a SES light and P030x codes since misfire is emissions/obd related. A half engine light (with no accompanying SES light) would indicate something else. Fuel pump or failed o2 sensor seem to be the most likely, imho.

Shiv

Correct.... I am getting the P030x codes, but only get the SES light after 2 half engine starts in a row. Going to get new plugs next week...

AKbmw · 03-10-2009, 03:04 AM

Would having my secondary cats removed have any problem with this? would the dealership void my warranty since i have no secondary cats, been in many times and they haven't said anything about it yet. if the problem is a spark plug then I am sure its ok that i have no secondary cats. Also saw the oil light come on too i need a quart of oil, would that have anything to do with it also?

and whats a P030x code?

Kbueno · 03-10-2009, 02:45 PM

Quote:

Originally Posted by shiv@vishnu

Bad plugs/misfire will cause a SES light and P030x codes since misfire is emissions/obd related. A half engine light (with no accompanying SES light) would indicate something else. Fuel pump or failed o2 sensor seem to be the most likely, imho.

Shiv

I never got codes, just a miss at idle. I'm sure eventually it would throw a code though.

tek818 · 03-10-2009, 03:44 PM

Quote:

Originally Posted by AKbmw

Would having my secondary cats removed have any problem with this? would the dealership void my warranty since i have no secondary cats, been in many times and they haven't said anything about it yet. if the problem is a spark plug then I am sure its ok that i have no secondary cats. Also saw the oil light come on too i need a quart of oil, would that have anything to do with it also?

and whats a P030x code?

I doubt the dealership would make a big fuss over missing secondary cats, but you never know-- I've never had an issue.

P030x codes are misfire codes where the "x" signifies which cylinder the misfire occurred on. i.e. P0301 = misfire on cylinder 1. I also got P0300 which is random misfire.

Fraggy · 03-10-2009, 04:07 PM

I have the same issue on cold start. All my morons did, even though they had TWO misfire codes stored for the same cylinder, was move the bad plug to a different cylinder to see if it replicates there. And yes, I still have rough starts, but no codes. Im about to go bonkers.

AKbmw · 03-27-2009, 03:30 AM

It's been about 2 weeks and I stopped getting the engine light and the start is not as harsh anymore ... I wonder what it was but I will still take it in because I doubt it fixed on it's own

bierry · 03-27-2009, 06:25 PM

on startups i have experienced unstable RPMs but goes away after car is warm. Is this normal?

03-09-2009, 05:58 PM	#1
AKbmw Brigadier General 262 Rep 3,253 Posts Drives: M-Sport LCI Join Date: Dec 2006 Location: LA iTrader: (13)	harsh idle in moarnings i just got back car back from the dealership because of a bad fuel pump. this morning (two days after the i got it back) when i started my car it started as soon as i pushed the button (unlike with a bad fuel pump there is a long crank) but when i was idling the car was shaking and acting weird, then i see the yellow half engine light or whatever. As i let it sit for 2 minutes or so, it went away and it was all good. i dont know why it did this as i just got it back from the dealer. what could this be? Note: i have had a Jb3 in the car before i took it to the dealer and also a BMS dual cone intake, and removed my secondary cats. right now i dont have the JB3 in the car (when the harsh idle happened) what could it be and what should i do? thanks! __________________
	Appreciate 0 Tweet Quote

03-09-2009, 06:01 PM	#2
OpenFlash 1806 Rep 17,960 Posts Drives: A Lot Join Date: Sep 2006 Location: SF Bay, CA iTrader: (0) Garage List 2018 Ducati Panigal ... [0.00] 2016 Mazda CX5 [0.00] 2017 Aprilia Tuono ... [0.00] 2019 BMW M2 Competi ... [0.00] 2015 BMW M5 Competi ... [10.00] 2016 Ducati XDiavel S [0.00] 2016 AMG GT S [0.00] 2011 Ferrari 458 It ... [0.00] 2017 Charger Hellcat [0.00] 2015 KTM Super Duke ... [0.00] 2016 KTM RC390 [0.00]	Do you still have the rough idle? Every time you start the car?
	Appreciate 0 Quote

03-09-2009, 06:39 PM	#6
RambleJ Colonel 60 Rep 2,014 Posts Drives: F10 535i M-sport Join Date: Oct 2008 Location: Back in teh so cal iTrader: (2)	If you have long cranks and a rough idle, it sounds like it may be another hpfp failure! I just started getting long cranks again yesterday, if this end up being a hpfp failure, it will be my third hpfp replacement
	Appreciate 0 Quote

03-09-2009, 06:49 PM	#7
Kbueno Lieutenant Colonel 101 Rep 1,712 Posts Drives: F82 Join Date: Jan 2007 Location: California iTrader: (5)	Also could be sparkplugs..it seems they go out over 15k and develop a miss at idle.
	Appreciate 0 Quote

03-09-2009, 09:12 PM	#11
OpenFlash 1806 Rep 17,960 Posts Drives: A Lot Join Date: Sep 2006 Location: SF Bay, CA iTrader: (0) Garage List 2018 Ducati Panigal ... [0.00] 2016 Mazda CX5 [0.00] 2017 Aprilia Tuono ... [0.00] 2019 BMW M2 Competi ... [0.00] 2015 BMW M5 Competi ... [10.00] 2016 Ducati XDiavel S [0.00] 2016 AMG GT S [0.00] 2011 Ferrari 458 It ... [0.00] 2017 Charger Hellcat [0.00] 2015 KTM Super Duke ... [0.00] 2016 KTM RC390 [0.00]	Bad plugs/misfire will cause a SES light and P030x codes since misfire is emissions/obd related. A half engine light (with no accompanying SES light) would indicate something else. Fuel pump or failed o2 sensor seem to be the most likely, imho. Shiv
	Appreciate 0 Quote

03-10-2009, 03:04 AM	#13
AKbmw Brigadier General 262 Rep 3,253 Posts Drives: M-Sport LCI Join Date: Dec 2006 Location: LA iTrader: (13)	Would having my secondary cats removed have any problem with this? would the dealership void my warranty since i have no secondary cats, been in many times and they haven't said anything about it yet. if the problem is a spark plug then I am sure its ok that i have no secondary cats. Also saw the oil light come on too i need a quart of oil, would that have anything to do with it also? and whats a P030x code? __________________
	Appreciate 0 Quote

03-10-2009, 04:07 PM	#16
Fraggy Brigadier General 198 Rep 3,469 Posts Drives: 2016 M3 Join Date: Jun 2005 Location: San Diego iTrader: (11)	I have the same issue on cold start. All my morons did, even though they had TWO misfire codes stored for the same cylinder, was move the bad plug to a different cylinder to see if it replicates there. And yes, I still have rough starts, but no codes. Im about to go bonkers. __________________ 2016 Alpine White M3 (gone) 2019 Alfa Romeo Guilia (Totaled) 2020 Car-less 😁 (no more) 2020 M340
	Appreciate 0 Quote

03-27-2009, 03:30 AM	#17
AKbmw Brigadier General 262 Rep 3,253 Posts Drives: M-Sport LCI Join Date: Dec 2006 Location: LA iTrader: (13)	It's been about 2 weeks and I stopped getting the engine light and the start is not as harsh anymore ... I wonder what it was but I will still take it in because I doubt it fixed on it's own __________________
	Appreciate 0 Quote

03-27-2009, 06:25 PM	#18
bierry Private 0 Rep 54 Posts Drives: pondering which tune again Join Date: Oct 2008 Location: us iTrader: (0)	on startups i have experienced unstable RPMs but goes away after car is warm. Is this normal?
	Appreciate 0 Quote