[BurrNinja]

On cold mornings I get a idle rpm flutter like its wanting to stall when I start my car. But, when it was warm it wasn't as bad. I ran injector cleaner through my system, the terrible idle would go away when I start. Is there a way to tell if it would be an injector? If not are there any other lists of things that might cause this? The idle would always happen when I turn my car off and back on. I checked my air filter pulling it off and starting it to see if it would subside, which it did not. Can you unplug the vanos solenoid to see if that is causing it or would unplugging it make it worse? Also, I cleaned my MAF to see if that would help which it didn't. Also there are no codes, no cel at all.

Also adding that, engine vibration noticing at 550 rpm. When I increased my idle using inpa to 650 it smoothed out.

[Wolf 335]

Your idle should be around 600-700 rpm.

You may want to consider doing the following.

-clean vanos solenoids
-pull spark plugs and inspect for oil accumulation.
-perhaps change spark plugs altogether
-inspect valve cover gasket for leaks

You may have a leaky injector. Once excess fuel burns off the idle stabilizes.
Same would apply for spark plugs. If valve cover is leaking it may saturate one or two plugs and cause issues until oil burns off.

Also, if you're filling up cheap gas at random noname stations you may want to reconsider. Lower tier gasoline may cause similar effects.

[PhaseP]

Check with inpa any hidden codes.
Also with inpa look at adaptation screens and see if anything is out of order like lambda multiplier, air flow, etc. That can give more info for diagnosis.
You should be looking at the values while engine is running.

[hassmaschine]

leaky injectors are certainly possible, but they are pretty rare on a port injected fuel system. I wouldn't jump to that first as a cause of your symptoms.

[BurrNinja]

Originally Posted by Wolf 335

Your idle should be around 600-700 rpm.

You may want to consider doing the following.

-clean vanos solenoids
-pull spark plugs and inspect for oil accumulation.
-perhaps change spark plugs altogether
-inspect valve cover gasket for leaks

You may have a leaky injector. Once excess fuel burns off the idle stabilizes.
Same would apply for spark plugs. If valve cover is leaking it may saturate one or two plugs and cause issues until oil burns off.

Also, if you're filling up cheap gas at random noname stations you may want to reconsider. Lower tier gasoline may cause similar effects.

I have all new ignition coils, spark plugs, i've cleaned and swapped vanos solenoids. I see a tiny i mean tiny bit of brown on the right side of the engine if you are looking at it from the front. Right under the intake manifold. I fill my gas up at speed way always putting 93 in.

[BurrNinja]

Originally Posted by PhaseP

Check with inpa any hidden codes.
Also with inpa look at adaptation screens and see if anything is out of order like lambda multiplier, air flow, etc. That can give more info for diagnosis.
You should be looking at the values while engine is running.

How do i go about looking at the lambda multiplier, and air flow. I've seen if the car had any hidden codes, nothing shown. No errors.

[BurrNinja]

Also, do you think. Cause ive heard that using bad gas like the lower octane ones will make the engine run rough but cause no issues. Is speedways 93 octane really 93? Or where should I test out other gas at around toledo ohio?

[PhaseP]

Originally Posted by blackwidow328i

How do i go about looking at the lambda multiplier, and air flow. I've seen if the car had any hidden codes, nothing shown. No errors.

When the engine is running with INPA chose engine, DME computer etc
Then "Status", then "Analog". Over there each screen gives lots of values of the currently running engine values, parameters. You can look all and try to see if anything is looking out of order. Don't remember what each screen had but you can see air temperature, coolant temperature, throttle position, and I believe one is amount of air going into engine (what MAF tells) and things like that.

I had rich running codes at one time, so I am somewhat more familiar with the screens related to that.
The "SA J1979" screen I think shows you "short time" fuel trim related values, i.e. what the computer at the moment finds the right amount of values to adjust the amount of fuel to get the right burn.
There is "Additive adaptation value" and "Multiplier Adaptation value" there. The later especially corresponds to fuel trim. They should be close to zero with a fully warmed engine. If the multiplier is negative, it indicates engine is finding rich running condition and is trying to compensate this by cutting off some fuel. If it is positive, the other way around.
Until these reach to a threshold value (could be 20% not certain though), no code is thrown.
Also if you click "Exhaust" button at the "Status" section, it will display "Adaptation Gemisch" screen. I "believe" this one also shows fuel trim values but they are for "long term", meaning what computer decided as optimal based recently after running the engine, not exactly what the running values are currently.

So, play around those it may give some info for better diagnosis.

I also don't think a leaky injector is likely with the N52. You can't even easily find a remanufactured one of those because they just work.

[BurrNinja]

Originally Posted by PhaseP

When the engine is running with INPA chose engine, DME computer etc
Then "Status", then "Analog". Over there each screen gives lots of values of the currently running engine values, parameters. You can look all and try to see if anything is looking out of order. Don't remember what each screen had but you can see air temperature, coolant temperature, throttle position, and I believe one is amount of air going into engine (what MAF tells) and things like that.

I had rich running codes at one time, so I am somewhat more familiar with the screens related to that.
The "SA J1979" screen I think shows you "short time" fuel trim related values, i.e. what the computer at the moment finds the right amount of values to adjust the amount of fuel to get the right burn.
There is "Additive adaptation value" and "Multiplier Adaptation value" there. The later especially corresponds to fuel trim. They should be close to zero with a fully warmed engine. If the multiplier is negative, it indicates engine is finding rich running condition and is trying to compensate this by cutting off some fuel. If it is positive, the other way around.
Until these reach to a threshold value (could be 20% not certain though), no code is thrown.
Also if you click "Exhaust" button at the "Status" section, it will display "Adaptation Gemisch" screen. I "believe" this one also shows fuel trim values but they are for "long term", meaning what computer decided as optimal based recently after running the engine, not exactly what the running values are currently.

So, play around those it may give some info for better diagnosis.

I also don't think a leaky injector is likely with the N52. You can't even easily find a remanufactured one of those because they just work.

I will have to look into this, if i post the screen shots with engine warmed up on here could you help me out on a diagnosis or would it be to hard to tell. I could even post a yt vid also.

[PhaseP]

I am no expert, I have some knowledge from chasing down rich condition codes, which eventually ended up being bad electrical connection at MAF sensor in my case.
I can try to help as much as I can though.

If you post the pictures here, others may also look and chime in and give input.

[hassmaschine]

Originally Posted by blackwidow328i

Also, do you think. Cause ive heard that using bad gas like the lower octane ones will make the engine run rough but cause no issues. Is speedways 93 octane really 93? Or where should I test out other gas at around toledo ohio?

no.. the engine will run fine even on 87 octane. just less power.

[dstrickland]

I've yet to run into this on an n52, but I'm sure it's happened. Maybe your fuel pump is worth looking into.

I just replaced on an e65 that had your exact symptoms.

[BurrNinja]

So my car is finally talking to me. On the way to get my lunch in between work schedule, I get a SEL reading P0171 System Too lean bank 1.

Tomorrow im going to my dads garage to check all the hoses for a possible air leak, or whatever else to see if I see a crack in any hose. Saying it is after the MAF sensor.

List goes as Causes.
-MAF dirty or faulty
-Vacuum leak downstream of MAF
- Possible cracked vacuum or PCV line/connection
-Faulty or stuck open PCV valve.
- Failed of faulty oxygen sensor.
- Sticking/plugged or failed fuel injector.
- Low fuel pressure, possible plugged/dirty fuel filter
- Exhaust leak between engine and first oxygen sensor.

Can INPA error reader tell me more into this code?

[DaanBMW]

Originally Posted by PhaseP

When the engine is running with INPA chose engine, DME computer etc
Then "Status", then "Analog". Over there each screen gives lots of values of the currently running engine values, parameters. You can look all and try to see if anything is looking out of order. Don't remember what each screen had but you can see air temperature, coolant temperature, throttle position, and I believe one is amount of air going into engine (what MAF tells) and things like that.

I had rich running codes at one time, so I am somewhat more familiar with the screens related to that.
The "SA J1979" screen I think shows you "short time" fuel trim related values, i.e. what the computer at the moment finds the right amount of values to adjust the amount of fuel to get the right burn.
There is "Additive adaptation value" and "Multiplier Adaptation value" there. The later especially corresponds to fuel trim. They should be close to zero with a fully warmed engine. If the multiplier is negative, it indicates engine is finding rich running condition and is trying to compensate this by cutting off some fuel. If it is positive, the other way around.
Until these reach to a threshold value (could be 20% not certain though), no code is thrown.
Also if you click "Exhaust" button at the "Status" section, it will display "Adaptation Gemisch" screen. I "believe" this one also shows fuel trim values but they are for "long term", meaning what computer decided as optimal based recently after running the engine, not exactly what the running values are currently.

So, play around those it may give some info for better diagnosis.

I also don't think a leaky injector is likely with the N52. You can't even easily find a remanufactured one of those because they just work.

OK, so I did some monitoring via INPA.

• The SAE values seem to stay steady in the green - 1st pic
  
  
• Rough running also look fine - pic 2
  
  
• Exhaust values are also god when stepping on the gas - pic 3
  
  
• Then something changes. The only time a value seems to go "in the red" is still in the exhaust but ONLY under coasting - which is where my #1 problem lies - pic 4. (Coasting = the car is in in gear, either going downhill or even road, almost like an engine braking but without switching to a low gear).
  
  As you can see the "lambda voltage before catalyst" is way out in both banks. Also the "Lambdawert vor Katalysator" is maxing out at 3.00 in both banks as well, and triggers an exclamation point.

Any idea as to what this can mean ?

___

[PhaseP]

While coasting computer cuts off the fuel, because engine is turning by the momentum of the car and you are not commanding it to accelerate (no gas pedal depressing). So no need to burn fuel unnecessarily.
I think this is what you are seeing at the 02 sensor output. No fuel is injected, no oxygen is burned in the engine, all of the oxygen entered to the engine from air comes out of the exhaust not burned. So air to fuel ratio goes way up measured by the 02 sensor. I think it is normal. Computer thinks normal too, it is not trying to compensate it.

[DaanBMW]

Originally Posted by PhaseP

While coasting computer cuts off the fuel, because engine is turning by the momentum of the car and you are not commanding it to accelerate (no gas pedal depressing). So no need to burn fuel unnecessarily.
I think this is what you are seeing at the 02 sensor output. No fuel is injected, no oxygen is burned in the engine, all of the oxygen entered to the engine from air comes out of the exhaust not burned. So air to fuel ratio goes way up measured by the 02 sensor. I think it is normal. Computer thinks normal too, it is not trying to compensate it.

That was what I thought too, since I know the injection is cut entirely. But if we know it, BMW knows it even better.

Why would it have 2 indicators per bank show as if they are really really off ? I mean one is in the red zone - which is clearly meant to flag a range where it should not normally operate. The other has an exclamation point, likely a feature to indicate that although no red zone is in the displayed range, the measured value is still interpreted as off. This kind of coasting operation is not that uncommon, esp. on manuals (and likely the #1 reason I drive way more spirited than the wife and yet I get similar or even better mpg)

Has no one run this exhaust gas test ? It would be v easy to confirm if this was indeed a legit operation flagged as bad (bit of a misnomer) or the sign that something's afoot ?

[PhaseP]

Originally Posted by DaanBMW

Has no one run this exhaust gas test ? It would be v easy to confirm if this was indeed a legit operation flagged as bad (bit of a misnomer) or the sign that something's afoot ?

There is nothing wrong. You are looking at a tool that displays the output of the sensors. Output of the sensors are not meaningful with those values when the car is coasting. The car computer knows this. The tool (INPA) doesn't, it just displays the values from the sensors. INPA is just doing that. It doesn't have the same logic as the car computer software to decide what is really wrong or not.

[Tdenardo218]

Originally Posted by BurrNinja

On cold mornings I get a idle rpm flutter like its wanting to stall when I start my car. But, when it was warm it wasn't as bad. I ran injector cleaner through my system, the terrible idle would go away when I start. Is there a way to tell if it would be an injector? If not are there any other lists of things that might cause this? The idle would always happen when I turn my car off and back on. I checked my air filter pulling it off and starting it to see if it would subside, which it did not. Can you unplug the vanos solenoid to see if that is causing it or would unplugging it make it worse? Also, I cleaned my MAF to see if that would help which it didn't. Also there are no codes, no cel at all.

Also adding that, engine vibration noticing at 550 rpm. When I increased my idle using inpa to 650 it smoothed out.

I had the same issue on my 2011 328i. I ran it to Texas from Arizona soon after getting it got pretty bad. When I got back, I ran the BG intake cleaning kit and BG 44k gas additive. Not too sure what the person before me ran as far as gas station, but I know the guy I bought it from ran 87 octane. Right after I ran the BG intake cleaner and 44k my problem cleared right up and I always use chevron 91 octane. Haven't had an issue since and my MPGs are better than ever.

[DaanBMW]

Originally Posted by PhaseP

There is nothing wrong. You are looking at a tool that displays the output of the sensors. Output of the sensors are not meaningful with those values when the car is coasting. The car computer knows this. The tool (INPA) doesn't, it just displays the values from the sensors. INPA is just doing that. It doesn't have the same logic as the car computer software to decide what is really wrong or not.

I understand the concept. But that is the reason I wanted this confirmed by practice not theory - did you run a similar engine and got the same readings under coasting in gear ? If not, it could be just a maybe AFAIC.

[hassmaschine]

Fuel is cut completely when you lift off the throttle in gear. Fuel Injected BMWs have done that since the 1970s (at least).

PhaseP is correct, there is nothing wrong.

[DaanBMW]

Originally Posted by hassmaschine

Fuel is cut completely when you lift off the throttle in gear. Fuel Injected BMWs have done that since the 1970s (at least).

PhaseP is correct, there is nothing wrong.

Look guys, don't get me wrong, but I feel I keep getting the answer to a question I'm not asking. I know the fuel is cut.

Something IS WRONG as my car does not properly recover to the idle rpm upon taking it out of gear after coasting...

Did anyone monitor this over INPA and got the same results as I did ?