[Coopaloop]

Hoping i can get some advice on an ongoing issue im having with my 2006 325i E90 Sedan.

The car runs and idles fine for about 20 min then very rough idle and complete stalling sputtering starts. (im told something about open and closed loop circuit) 2 mechanics have kicked it out now not being able to figure it out. heres a list of replaced parts.

ECU
VVT
Fuel pump
MAF
Camshaft position sensor
Throttle body
6 Spark plugs
6 Coils
Both Vanos Solenoid's.

the problem is definitely electrical as it competely loses all power entirely then all of a sudden is fine again for a few seconds. it will start back up again and again until some point where it no longer will. i have to leave it overnight and it will start back up again no problem the next morning.

Car is throwing no codes at all

before all this started happening i had some oil mixing with the coolant but was quickly repaired (oil housing gasket)

other than that nothing has ever been mechanically wrong with the car.

ive been just throwing money at this vehicle and would just like to know if there is a known electrical fault somewhere in the harness maybe? i dont know any help would be very appreciated.

Thank you

[gbalthrop]

Car is throwing NO Codes at all, and you've replaced ALL THAT? You should have "kicked out" your two "mechanics" instead of "other way around".

Are you aware that INPA or ISTA will allow you to monitor LIVE DATA of Signals from various components, such as Fuel Pump, VANOS Solenoids and Cam Position Sensors, DME Main Relay, Crankshaft Sensor RPM Signal, MAF air flow rate signal, etc.? Using that software, you can see what changes when the hesitation or stalling occurs.

Did either shop use any such Diagnostic Software (view data on Laptop screen) or a Scan Tool that can similarly monitor Live Data? Did they monitor Fuel Pump operation? Did they try to Activate the Fuel Pump when the engine began to falter or stall, or read Pump voltage or RPM?

Your intuition that there is an intermittent electrical fault, or perhaps temperature-related electrical fault, such as fuel pump NOT working properly after 20 minutes of function, is almost certainly correct. If the engine is stalling after 20 minutes of PROPER operation, that means it is ceasing to get (1) fuel delivery to rail at proper volume/pressure; (2) Injector pulse to supply fuel to the cylinders; (3) Properly-timed spark at plugs; and/or (4) DME Power supply or function to pulse coils and injectors.

What you need to understand is that INPA or ISTA Diagnostic Software (free downloads available) can allow you/ your Tech (someone who actually understands how BOTH the Engine DME and Diagnostic Software work ;-) to observe LIVE DATA with engine running. That Data includes ALL the DATA from the Crankshaft Sensor, Cam Position Sensors, VANOS Solenoids, DME Main Relay, MAF Sensor, Rough running (to determine if several cylinders as opposed to all cylinders alike are affected), Fuel Pump Temp, Voltage & RPM, and DME Signal to Fuel Pump Module, and MORE.

You don't have to disassemble or disconnect ANYTHING. Just plug the K+DCAN Cable into the OBD II Socket and watch the show. The User DOES have to understand HOW to connect to the DME, and also to the EKPS Fuel Pump Module, and WHAT Screens to select, but if he knows THAT MUCH, he can see the Live Data, and doesn't have to GUE$$ and throw part$ at your expen$e.

Even if YOU don't have the Laptop with software installed to DIY, you at least need to be aware of GENERALLY what diagnostic tools are available, what their capability is, and how to find a shop that has those tools and knows how to use them.

My SWAG is that you should test the fuel pump using INPA, observing Voltage, Temp & RPM with the engine running at idle. Drive ~ 10 minutes, and then let engine continue to idle for another ~ 10-15 minutes as you watch Live Data of Fuel Pump "Parameters". If pump parameters change just before, or at the Start of, stalling or reduced power/ engine RPM, you have a problem with the pump, the Pump Module, or the wiring between DME & Module. There are tests for those things too, but first step is to determine what component(s) is/are ceasing normal function at START of stalling.

George

[gbalthrop]

It would be helpful if you provide additional facts or details about what happens once the engine stalls.
1) Does it start at least once or twice and run for a few seconds?
2) When it restarts, is it smooth for a few seconds?
3) Does it progressively take longer to fire upon Starter Cranking after stall?
4) Does it ultimately just "Crank" with no sputter or attempt to fire, as if it were "out-of-gas"?

If so, it probably IS, in EFFECT, Out of GAS, as the pump is NOT supplying fuel to the rail. A failing fuel pump often fails due to internal temperature related to how LONG and at what RPM or Delivery Rate it has been running. Your initial post makes no mention of testing or replacement of the Fuel Pump or Pump Module. I would begin with such TESTING.

Also, be aware that there is a "Jet Pump" within the tank that pumps fuel from the Left side of the Tank "Saddle" to the Right side where the Pump is located. If that Jet Pump is NOT working, you can have the Fuel Gauge reading 1/4 tank or slightly more, with the Left side nearly full, but with NO FUEL on the RIGHT side, where the pump is. If your issue occurs with > 1/2 tank shown on Fuel Gauge, then the Jet is NOT your problem.

INPA can show you the amount of fuel level in EACH half of the tank (there are separate sensors). The fuel gauge ONLY shows you the TOTAL amount, adding the two separate Sensor values together.

George

[Coopaloop]

Originally Posted by gbalthrop

Car is throwing NO Codes at all, and you've replaced ALL THAT? You should have "kicked out" your two "mechanics" instead of "other way around".

Are you aware that INPA or ISTA will allow you to monitor LIVE DATA of Signals from various components, such as Fuel Pump, VANOS Solenoids and Cam Position Sensors, DME Main Relay, Crankshaft Sensor RPM Signal, MAF air flow rate signal, etc.? Using that software, you can see what changes when the hesitation or stalling occurs.

Did either shop use any such Diagnostic Software (view data on Laptop screen) or a Scan Tool that can similarly monitor Live Data? Did they monitor Fuel Pump operation? Did they try to Activate the Fuel Pump when the engine began to falter or stall, or read Pump voltage or RPM?

Your intuition that there is an intermittent electrical fault, or perhaps temperature-related electrical fault, such as fuel pump NOT working properly after 20 minutes of function, is almost certainly correct. If the engine is stalling after 20 minutes of PROPER operation, that means it is ceasing to get (1) fuel delivery to rail at proper volume/pressure; (2) Injector pulse to supply fuel to the cylinders; (3) Properly-timed spark at plugs; and/or (4) DME Power supply or function to pulse coils and injectors.

What you need to understand is that INPA or ISTA Diagnostic Software (free downloads available) can allow you/ your Tech (someone who actually understands how BOTH the Engine DME and Diagnostic Software work ;-) to observe LIVE DATA with engine running. That Data includes ALL the DATA from the Crankshaft Sensor, Cam Position Sensors, VANOS Solenoids, DME Main Relay, MAF Sensor, Rough running (to determine if several cylinders as opposed to all cylinders alike are affected), Fuel Pump Temp, Voltage & RPM, and DME Signal to Fuel Pump Module, and MORE.

You don't have to disassemble or disconnect ANYTHING. Just plug the K+DCAN Cable into the OBD II Socket and watch the show. The User DOES have to understand HOW to connect to the DME, and also to the EKPS Fuel Pump Module, and WHAT Screens to select, but if he knows THAT MUCH, he can see the Live Data, and doesn't have to GUE$$ and throw part$ at your expen$e.

Even if YOU don't have the Laptop with software installed to DIY, you at least need to be aware of GENERALLY what diagnostic tools are available, what their capability is, and how to find a shop that has those tools and knows how to use them.

My SWAG is that you should test the fuel pump using INPA, observing Voltage, Temp & RPM with the engine running at idle. Drive ~ 10 minutes, and then let engine continue to idle for another ~ 10-15 minutes as you watch Live Data of Fuel Pump "Parameters". If pump parameters change just before, or at the Start of, stalling or reduced power/ engine RPM, you have a problem with the pump, the Pump Module, or the wiring between DME & Module. There are tests for those things too, but first step is to determine what component(s) is/are ceasing normal function at START of stalling.

George

Im lightly versed in the live data readout and trouble codes so im absolutely at a loss. but both the so called mechanics supposed to know how go fix cars right? . but according to them there is no significant change anywhere in the data stream before or during the stalling.

One of the mechanics was BMW Certified mechanic, hes the one who did the ECU swap and the VANOS. theres werent just guys in theyre garage trying to fix my car they are both reputable mechanics with buisneses. but still couldnt figure this out.

fuel pump was also changed. this is certainly an electrical issue somewhere. but like i said both mechanics are saying no significant change in any of the live data to determine a fault location.

[Coopaloop]

Originally Posted by gbalthrop

It would be helpful if you provide additional facts or details about what happens once the engine stalls.
1) Does it start at least once or twice and run for a few seconds?
2) When it restarts, is it smooth for a few seconds?
3) Does it progressively take longer to fire upon Starter Cranking after stall?
4) Does it ultimately just "Crank" with no sputter or attempt to fire, as if it were "out-of-gas"?

If so, it probably IS, in EFFECT, Out of GAS, as the pump is NOT supplying fuel to the rail. A failing fuel pump often fails due to internal temperature related to how LONG and at what RPM or Delivery Rate it has been running. Your initial post makes no mention of testing or replacement of the Fuel Pump or Pump Module. I would begin with such TESTING.

Also, be aware that there is a "Jet Pump" within the tank that pumps fuel from the Left side of the Tank "Saddle" to the Right side where the Pump is located. If that Jet Pump is NOT working, you can have the Fuel Gauge reading 1/4 tank or slightly more, with the Left side nearly full, but with NO FUEL on the RIGHT side, where the pump is. If your issue occurs with > 1/2 tank shown on Fuel Gauge, then the Jet is NOT your problem.

INPA can show you the amount of fuel level in EACH half of the tank (there are separate sensors). The fuel gauge ONLY shows you the TOTAL amount, adding the two separate Sensor values together.

George

1) yes, over and over itll start back up for while then i have to let it sit overnight before itll start again

2) yes

3) yes

4)yes, once it has started and stalled a bunch of times


the pump was changed, but i will definently pass this information on.

but since the car starts and runs again when its cold, wouldnt the fuel pump be ruled out asa possible problem?

[gbalthrop]

Originally Posted by Coopaloop

...fuel pump was also changed. this is certainly an electrical issue somewhere. but like i said both mechanics are saying no significant change in any of the live data to determine a fault location.

SOMETHING is causing loss of fuel supply or spark (or both). I listed all the different things I could think of to monitor or test once "Stalling" sequence begins, and HOW INPA (or ISTA) could monitor the Live Data. I'm NOT saying it's easy. There are a half-dozen screens one would need to monitor at moment of stall, one at a time.

Unfortunately, this is a classic example of WHY it takes time, and/or MONEY to diagose such issues. An intermittent fault, that appears to be temperature-related, but does NOT cause a Fault Code to be saved, is tough to diagnose. Are you SURE there is NO Warning Light or SES light on the Dash when this occurs?

Faults may be related to the length of time a module or component has been operating and built up internal temperature. Fuel pumps are such components, similar to ANY electrical motor, where temperature slowly rises with use, and if the motor components are worn, the temperature increases too much (friction) and the motor slows, gets hotter, slows more, recovers if cooled for a moment and then gets slowly worse.

Of course I have NO way of knowing your fuel pump is the cause. What I DO know:

1) The engine stall sequence you describe is consistent with a failing fuel pump. That would be particularly true if the stalling is "Progressing" where it happens more quickly in the drive, or more frequently.

2) Using either INPA or ISTA to "Activate" or run the Fuel Pump (which you can hear inside the car with engine & audio off) would indicate whether pump is running at all when engine no longer fires during Starter Cranking. Installing a mechanical pressure gauge on the fuel rail (at the injectors) is fairly quick & easy on N52 engine (325i) as there is a Schrader Valve (like tire valve) already in place to which gauge can be attached.

3) INPA will show you ACTUAL LIVE DATA of Fuel Pump RPM (assuming you have EKPS Fuel Pump Module & NOT a Fuel Pump Relay as some early models had). Viewing that data, you can CLEARLY SEE if Pump quits running. It should NOT, even if motor stalls, unless power has been disconnected or pump motor has quit "motoring".

4) SOMETHING is stopping or going open circuit to cause the Stall, and IF there is NO fault code, you can ONLY monitor ALL the Live Data, one screen at a time, to catch the "Fault in the Act", like watching a surveillance camera stream instead of a motion-activated camera that takes a snapshot.

Originally Posted by Coopaloop

...the pump was changed, but i will definitely pass this information on. but since the car starts and runs again when its cold, wouldn't the fuel pump be ruled out as a possible problem?

My Concept is NO, for reasons described above. Actually there are other possible causes of loss of fuel pressure OTHER than pump failure, such as an issue with the pressure regulator, etc. But a mechanical pressure gauge mounted on the fuel rail would be the definitive answer of fuel delivery/ pressure issues. Nominal Fuel Pressure from tank pump on N52 engine is 6 bar = 72.5 PSIG. The symptoms you describe are "Consistent" with "Decaying" or slowly reducing fuel rail pressure, that gets lower & lower as pump RPM and delivery rate gets lower & lower, until you have to leave it for several hours until the fuel in the tank cools the motor, and then the cycle starts again.

I try NOT to "Fall in Love" with the FIRST "POSSIBLE Cause" of an issue that I identify. This is NOT a battle of Wits. It's merely a suggestion of things to test, and HOW to test.

I will attach to the NEXT post an INPA ScreenPrint of the Fuel Pump Activation Screen. This shows Pump Actual Speed, Voltage, Amps & Temperature. That Screen was saved with engine (N52K) at warm idle, and with Pump under EKPS Module Control. I did NOT select a speed to "Over-ride" EKPS Control of pump speed. I was ONLY monitoring its function. You CAN "Over-ride" Module control and select a TARGET value, such as 50% of max, and see if Actual Pump Speed increases or decreases accordingly. That tests the control circuit.

Of course if you just have relay control, the pump is either OFF or ON, you have NO EKPS Module, and you would test the fuel pump via the DME Module instead of the EKPS Module (which is NOT used if you simply have a Fuel Pump relay). Of course, the mechanical gauge, mounted to the fuel rail, would be the BEST proof of fuel pump & regulator function, REGARDLESS of which Pump Control System your vehicle has.

Please let us know how it goes,
George

[gbalthrop]

Attached is ScreenPrint of my 3/2007 328xi at warm idle, WITHOUT Over-ride of EKPS Control of Pump.
Menu Path/Sequence: INPA > EKPS > F6 EKP Data; NO Function button selected on Taskbar; Observing ONLY, NOT Activating
If you wish to Over-ride EKPS Module control of pump:
a) press F1/SET L and select Liters per hour flow rate; or
b) press F2/Set PWM and select Pulse Width Modulation % of max value
Observe Actual Pump Speed and other Values to see effect of TARGET change

George

[Coopaloop]

ok. it looks like i have a lot to do. i will let you know what i find.

thank you

[xr7dave]

I know this is an older thread, but I also have an 06 325 sedan with very similar issues. Mine has never failed to start, but it will cut out completely, generally for only a second and then continue to run like nothing happened. No codes.

My thoughts were fuel pump, as it definitely gets worse on warm restarts. But it will do it on decel as well as accel making me think it's not demand or load related. Usually a fuel pump with reduced output will act up more under load. I have no problem replacing a pump, but I do have a problem replacing parts that don't address the actual problem.

My other thoughts were crank sensor as it seems to lose all tach when it happens. Idk exactly where the actual tach gets is actual signal from, but this car is a manual trans so the rpms can't drop to zero when you are cruising down the highway. So it's at least partially electrical.

No other electrical systems in the car are affected. Only the engine.

Lately warm restarts are so bad it can't be driven. The only two codes I have gotten are 2EEC and 2F80. I've cleared the 2EEC a couple times and it does come back. The 2F80 just came on last night for the first time and SES is now on continuously for the first time as well.

[Kindsoul]

My 2012 BMW 328i stalled twice on the freeway, similar to what the original poster (OP) experienced. The first incident happened two weeks ago, and I was shocked and didn't know what to do. I was just sitting there. Thankfully, some kind people stopped and helped push my car to the shoulder. They were amazing.

This had never happened before. The dashboard showed a warning sign: a car icon with two perpendicular lines touching the ground, and a message indicating a fuel pump issue. I called my insurance company to send a tow truck, but the CHP officer said they'd take too long to arrive and offered to call their own tow truck. It showed up in about 30 minutes, but the tow driver charged nearly $465 for a less than 7-mile tow. He explained that the CHP charges a certain amount per hour, and some of the fee goes to them.

Anyway, I was relieved to get off the freeway and have my car towed to a repair shop. The mechanic there couldn't identify the cause of the stall. So, I told the shop manager to replace the fuel pump since the dashboard had pointed to it. They replaced it, and I thought the problem was resolved. The car ran fine on local roads over the weekend.

However, on my way home from work—about 45 miles away—it stalled again, exactly as it had the previous week. This time, I didn’t call CHP. I contacted my insurance company for a tow truck. While waiting, all the lights on the dashboard suddenly went out. I thought the battery was dead, so I instinctively pressed the start button. To my surprise, the car started up again.

I wasn’t sure whether I should wait for the tow truck or risk another stall on the busy freeway and the potential danger of getting rear-ended. In the end, I decided to drive it back to the same repair shop. It's been two days now, and I haven’t heard back from them.

After the first stall, the mechanic replaced the fuel pump, fuel control module, and another part related to the fuel system. The shop manager told me that all parts came from the dealer, since my car has a combined fuel pump and filter module.

Despite replacing these components, the same stall issue occurred. Even though the shop says they've fixed the car, I’m afraid to drive it on the freeway again.

I’m not sure if they can even fix the problem. What’s causing the issue?