Idle problems... stalls on start up. Need help!

[Ssgohan434]

Car was having problems nearing stalling on start up 2 weeks ago with a rough idle and the revs bouncing. This would only happen on the first start up of the morning and would go away on subsequent start ups throughout the day. Car gave a P0175 and misfire codes. Erased the codes and thought they might go away. But it's been about 2 weeks and now the car has problems with start up.... instead of starting up with a rough bouncy idle the car will actually stall. (DCT). It takes about 2 or 3 starts to get going with a roughy bouncy idle still occurring. Only occurs on morning start up and doesn't come back with subsequent start ups throughout the day.

Car doesn't have any problems holding idle revs at stop lights or any other time except the initial morning start up.

If it did have problems with holding idles at other times of the day it would likely be the ICV right?

I'm so far hypothesizing that its the low pressure sensor.... am I right??
Need input from m3 brethren

[elm3]

Originally Posted by Ssgohan434

Car was having problems nearing stalling on start up 2 weeks ago with a rough idle and the revs bouncing. This would only happen on the first start up of the morning and would go away on subsequent start ups throughout the day. Car gave a P0175 and misfire codes. Erased the codes and thought they might go away. But it's been about 2 weeks and now the car has problems with start up.... instead of starting up with a rough bouncy idle the car will actually stall. (DCT). It takes about 2 or 3 starts to get going with a roughy bouncy idle still occurring. Only occurs on morning start up and doesn't come back with subsequent start ups throughout the day.

Car doesn't have any problems holding idle revs at stop lights or any other time except the initial morning start up.

If it did have problems with holding idles at other times of the day it would likely be the ICV right?

I'm so far hypothesizing that its the low pressure sensor.... am I right??
Need input from m3 brethren

You could have a low pressure sensor problem, but also an ICV issue. How many miles? Under warranty? Have the dealer diagnose the problem.

[Grail05]

if its only giving you the P0175 it definately the low pressure sensor .... change that and instantly you will notice the idle will stay steady.... this happen to me.. and it kept giving me the p0175....

check this out...
http://www.m3post.com/forums/showthr...ighlight=p0175

REPLACING THIS COST 65 BUCKS FOR ME... GOT IT AT MCKENNA BMW... depends if your out of warranty if you are... buy it from them.... cheap way to troubleshoot before going with ICV...

[RBB]

This seems to be all too common around here lately. I've been having the stumbling RPMs on morning starts lately as well. Haven't thrown any codes yet, but I already ordered the LPFS to have on hand if needed.

[Grail05]

Originally Posted by RBB

This seems to be all too common around here lately. I've been having the stumbling RPMs on morning starts lately as well. Haven't thrown any codes yet, but I already ordered the LPFS to have on hand if needed.

sounds like yours is about to go out... mine did the same for 3 months my idle was all weird until i got the code... took another month to troubleshoot... since the link i provided the OP on that thread got a different codes then in the end p0175 code stayed which was the case so i decided to replace that part.. its been a month and half now and the day i replaced my Low Pressure Sensor it was instantly a night and day

now im dealing with my sticky AC.. im putting a smoke bomb hoping to get rid of it...

[RBB]

Originally Posted by Sean05

sounds like yours is about to go out... mine did the same for 3 months my idle was all weird until i got the code... took another month to troubleshoot... since the link i provided the OP on that thread got a different codes then in the end p0175 code stayed which was the case so i decided to replace that part.. its been a month and half now and the day i replaced my Low Pressure Sensor it was instantly a night and day

now im dealing with my sticky AC.. im putting a smoke bomb hoping to get rid of it...

Well at least this issue is a cheap and easy DIY. I'm all for that.

[Ssgohan434]

Also had P0191 come up (Fuel Rail Pressure Sensor) come up....

I've gone ahead and ordered the low pressure sensor for about $60 shipped.

[Grail05]

Originally Posted by Ssgohan434

Also had P0191 come up (Fuel Rail Pressure Sensor) come up....

I've gone ahead and ordered the low pressure sensor for about $60 shipped.

then if thats the case it is definately the low pressure sensor... that code also came out but after clearing several codes p0175 stayed ... your low pressure sensor is bad..

[caroaustini]

I've been having the stumbling RPMs on morning starts lately as well.

[GrussGott]

Originally Posted by caroaustini

I've been having the stumbling RPMs on morning starts lately as well.

2011 with 11k and I just started getting the stumbling idle on morning start a few days ago. It will start fine and then the revs almost drop to zero, it over revs, then goes back to normal.

Today it did that, I waited, and then drove down my parking ramp. As I was going to pull out I started with with the throttle and the revs dropped to almost zero again and popped back.

I pulled away and then 1 block later the dash lit up like a christmas tree: low power mode, DSC error, engine malfunction, etc. I pulled over, shut it down, waited a minute or 2, then re-started and had no more problems today.

ICV or pressure sensor?

[RBB]

Originally Posted by GrussGott

2011 with 11k and I just started getting the stumbling idle on morning start a few days ago. It will start fine and then the revs almost drop to zero, it over revs, then goes back to normal.

Today it did that, I waited, and then drove down my parking ramp. As I was going to pull out I started with with the throttle and the revs dropped to almost zero again and popped back.

I pulled away and then 1 block later the dash lit up like a christmas tree: low power mode, DSC error, engine malfunction, etc. I pulled over, shut it down, waited a minute or 2, then re-started and had no more problems today.

ICV or pressure sensor?

Now that sounds like the ICV. I've had the rev hunting before but its just for a few seconds after start up and the RPM's never dip below 700 or so. Better head to the dealer....

[GrussGott]

Originally Posted by RBB

Now that sounds like the ICV. I've had the rev hunting before but its just for a few seconds after start up and the RPM's never dip below 700 or so. Better head to the dealer....

Ah feck. thanks for the call.

[BPMSport]

Fault 275E - P0175 - Bank 2 oxygen sensor limit position fault

Service action:
1. Check fuel system for leaks, initiate test routine as indicated
2. Check exhaust system for leaks
3. Check intake system for leaks and correct operation
4. Read out oxygen sensor diagnostic data, perform both oxygen sensor test routines

This can be a collateral error caused by something else, such as an ICV. But I would verify o2 sensors and everything above are checked.

[elm3]

Originally Posted by Mike Benvo

Fault 275E - P0175 - Bank 2 oxygen sensor limit position fault

Service action:
1. Check fuel system for leaks, initiate test routine as indicated
2. Check exhaust system for leaks
3. Check intake system for leaks and correct operation
4. Read out oxygen sensor diagnostic data, perform both oxygen sensor test routines

This can be a collateral error caused by something else, such as an ICV. But I would verify o2 sensors and everything above are checked.

Hey Mike, if I have the BT cable, can I perform the O2 read out check with it? What would be the norm on a read out?

[GrussGott]

Originally Posted by Mike Benvo

Fault 275E - P0175 - Bank 2 oxygen sensor limit position fault

Thanks mike! I'm assuming I can't check those codes without jacking in to the OBDII port? Or is some spelunking of the menus I can do to see the codes?

thanks again

[M3Comet]

Originally Posted by Ssgohan434

Car was having problems nearing stalling on start up 2 weeks ago with a rough idle and the revs bouncing. This would only happen on the first start up of the morning and would go away on subsequent start ups throughout the day. Car gave a P0175 and misfire codes. Erased the codes and thought they might go away. But it's been about 2 weeks and now the car has problems with start up.... instead of starting up with a rough bouncy idle the car will actually stall. (DCT). It takes about 2 or 3 starts to get going with a roughy bouncy idle still occurring. Only occurs on morning start up and doesn't come back with subsequent start ups throughout the day.

Car doesn't have any problems holding idle revs at stop lights or any other time except the initial morning start up.

If it did have problems with holding idles at other times of the day it would likely be the ICV right?

I'm so far hypothesizing that its the low pressure sensor.... am I right??
Need input from m3 brethren

Did you figure out what it was?

[M3Comet]

Hi everyone, I drive my 2013 once or twice per fortnight, I tried the battery charger option with no results.
I then tried the ignition only (not the engine) technique for one minute prior to starting the engine. If it's been a few days, no issues, I started it yesterday for the first time in 14 days, a little burble or two, but stabilised almost straight away. Not a perfect fix, but enough for me.
Maybe a capacitor/battery within the ignition/computer module?