N62 - Misfire at Idle P0300, P0301 ect.
 

Hello Guys,

It's been a while since my last post here. My 2006 4.4l sport has been running like a champ until today.

I went for a drive and I pulled up to a light and I get a flashing CEL
and the idle starts to lope. I pull away with a loss in power so I pull to a parking lot, shut the engine off and plug in my Bluetooth scanner and get the torque app up on my phone.

I restart my X and the severe misfire I was experiencing before shut down is almost completely gone and seems to be idling fine. My CEL is still illuminated.

I scan the car and it was showing a P0300 like I knew it would for random cylinder misfire.
I then checked historic faults and see

P0301
2
4
5
6
8
So it logged misfires on all cylinders except 3 and 7

Then I clear codes with it running and instantly the idle goes back to normal and its running like I expect. I get on my way and its running fine. A mile or 2 later I pull up to a stop light and after 30 seconds at idle it starts to flash my CEL and misfire.

Hopefully that's not to much of a novel I like to be as specific as I can in how a symptom is manifesting itself.

Is this obvious for you fellow N62 members on where I should start with this one? I've fixed these symptoms with ignition coils and swapped out hoses and intake plastics on other BMWs in the past when vacuum leaks manifested themselves in a similar fashion.

Where would you start?

Thanks in advance guys!

sounds like air intake , and MAF sensor might need to be checked and reset ............

Since you have the App Torque see what the short term fuel trim and long term fuel trim for each bank is doing. Check the voltage for the 02 sensors 1 and 2 (pre cat and post cat) for both banks. You can also look at the air flow rate at the MAF, it will be g/s.

Idle related misfires are rarely coil/spark plug related.

Need to see Freeze Frame data and warm idle Fuel Trim values.

Might as well set up the Logging because this can be shared with someone like myself that can analyze and graph the data.

This is some older data I put together, not sure if the menus/layout has changed.

Start Torque Pro program on Droid device.

Touch the Droid Menu button.

Choose Settings in Torque Pro.

Choose Data Logging & Upload.

Select what to Log, choose only things you need to Log for faster logging.

Select File Logging Interval, start with 1 second unless you have only a few items to Log.

Select Log When Torque Is Started.

Select Only When OBD Connected.

Unselect Automatically Log GPS, this is a time and resource waster for OBD Logging.

Decide what you want to select for Rotate Log Files.

Select Format Log Files.

Enter User Email Address.

Test Settings

From Realtime Information page, select the Droid Menu, select Email Logs, select what "TrackLog" to email and it should be in the CSV format.

I usually recommend setting up a DropBox Free account and upload the .CSV files to DropBox and then paste the share URL link back in the thread so people can download and review the data.

Thanks for the replies guys!

I did some more scanning with torque this evening and looked for the stuff you mentioned. I'm using the free version, not pro but I was able to pop around in some menus and find a few things.

The most notable of which is Fuel/Air Status widget

It has 2 categories

Fuel system status And Secondary air status

With no CEL light illuminated and it running fine.

The Fuel system status category reads:
Closed loop system running or system reading form o2 sensors

and the Secondary air status just reads:
System not supported

Once it starts to idle funny throw a CEL light solid or flashing the

Fuel System Status category reads:
Open Loop due to system failure

So that got me thinking if when its running fine it says its receiving data from the o2 sensors. in that category and when it's misfiring that category says open loop system failure.

Then I toggled display on for O2 sensor voltage for bank 1 and 2, not sure if they were pre or post or what it was letting me read but I this is what I saw.

Running fine with a cleared ECU after fresh start it drives fine like I mentioned in my earlier post. The values on both banks raise and fail equally as I speed up and slow down. When I stop and it starts to idle I notice that bank 2 shoots all over the place and then the CEL illuminates and I get 0.0V from both banks.

Does this point to a possible o2 sensor issue?

Here are some screen shots

http://www.xoutpost.com/members/lexi...re2583-1-1.jpg
http://www.xoutpost.com/members/lexi...re2585-1-2.jpg
http://www.xoutpost.com/members/lexi...re2584-1-4.jpg

This is not likely an O2 sensor issue, trust me.

If you are only using Torque Free, move on from Torque Free and spend the $3.99 and buy OBDFusion, it is far better than Torque Pro as far as I am concerned.

I need to see Freeze Frame data Logged data will tell me WAY more than you can convey.

This problem is likely a Lean problem which will be clearly shown with the data.

Lean conditions are more often than not due to vacuum and/or crankcase air leaks. Occasionally a soft failing fuel pump could be an issue as well.

For vacuum or crankcase air leaks, smoke testing is the easiest way to figure out if and where a leak is.

Here some examples of ways to smoke test:

https://www.youtube.com/watch?v=AsgB9eBl58I

https://www.youtube.com/watch?v=PnU-SY6egr4

https://www.youtube.com/watch?v=zMok2y05jNE

The system was in closed loop, but it went to open loop

http://www.xoutpost.com/members/lexi...re2583-1-1.jpg

How can you say that it is not a 02 sensor issue? Since he has the app torque I would suggest the OP monitor the 02 sensor voltages for ALL of the Sensors.

The sensor that the OP posted is for the post cat 02 (B1S2) sensor, you need to post the 02 B1S1 and 02 B2S1 voltage readings as that is what is used by the DME to control the engine.

http://www.xoutpost.com/members/lexi...re2584-1-4.jpg

Short term fuel trim will tell you if the engine is running lean. If the fuel trims are in the plus range that mean the DME is commanding the system to add fuel. Fuel trim numbers will have to be over 10% for a lean condition.

I deal with this ALL the time, snap shot data from people that do not know what is required leads to miscues and unnecessary parts replacement.

The ONLY time I ever see O2 sensor faults that actually trigger codes is when the heater(s) fail in the sensors. I find that lazy O2 sensor rarely show up and are flagged by the DME/ECU.

Also I do not trust Torque, had too many problems with it and the App developer is non responsive.

Fuel System Status changes for many reason, to include deceleration with fuel cut off and I do not believe Torque actually reports accurately the 5 states for the Fuel System Status.

You also cannot analyze any data other than maybe engine temperature with a snap shot from the gauges.

Logs are REQUIRED to get the full picture and Logs cut down on easily 20+ posts in a thread back and forth trying to get the full picture and data from someone that barely understands how to use the App or has limited understanding of OBDII.

Even if the OP posts the Pre-cat O2 sensor Voltages from a single snap shot, this means NOTHING. Logging is the only way to see everything that is going on. Additionally Freeze Frame data is very helpful to understand under what conditions any codes were stored.

I fully understand Fuel Trim values and often find that there are problems when in fact there is no SES/CEL/MIL. Again, Logs when set up properly will show the entire picture. Just because the SES/CEL/MIL is not on does not mean there are no problems.

Data is key analyzing any driveability problem and will either rule in or out specific problems or subsystems.

BTW, 3.5 g/s MAF reading at idle seems a bit low for a 4.4l V8.

SMOKE Tester DIY. Let me know if you guys can't see pics.

How to: Build an emission smoke leak detector - The Garage Journal Board

Quicker and cheaper - https://www.youtube.com/watch?v=AsgB9eBl58I

Pump is a cheap fluid transfer pump that most auto parts store have, a rubber glove and a cheap cigar!

Why bother with a transfer pump!!!

https://www.youtube.com/watch?v=zMok2y05jNE

I know all about Professor Scotty.

The benefit of the transfer pump is you can provide a continues stream of smoke under pressure much easier than the Professor Scotty method.

Often there are crankcase air leaks and cracked or leaking valve covers and you need to remove the oil fill cap until smoke is coming out of the oil fill hole, then recap the crankcase. Then watch carefully for smoke to escape. You might get pretty winded trying to fill the crankcase and keep everything under pressure. Kind of like blowing up an air raft or mattress, you will not last long.

Professor Scotty's method is good for large leaks, but the smaller leaks are better found with a fixed/continuous pressure.

Thanks again for all the replies guys.

I drove the x yesterday and it seemed to exhibit the issue much less then sunday afternoon when it showed itself.

I still got the flashing SES light when I pulled up to a stop. But once the light came on and stayed illuminated and I didn't clear the codes or reset the light it seemed to function the rest of the day with little to no misfiring or Flashing SES light.

I did rescan codes and came up with 1 new code we have not seen before. I got so excited hoping it would tell me the failed part like no data from an o2 sensor or CPS failed ect. but alas its was a generic P2187, System too lean at idle bank 1

I also pulled a screen up for Drive status since DTC clear and all the available systems show complete behind them in green text except Evaporitive Sys: it reads Incomplete in yellow text.

Observation : My torque free app will only show o2 sensor data from Bank 2 sensors 1 and 2

When I scroll through the menu I see the other banks way down on the list but no astrict by them meaning no data being sent.

Is this a restriction of the free version? I shouldn't worry about not being able populate a gauge with live data from that bank like something is disconnected or failed for proper metering of that bank correct?

I will get the stuff together for a smoke test I guess. Also I emailed my log data from torque free in CVS for to myself but when I opened it it only seemed to have GPS data from my trip. So must not be able to get the live snap shot data with the free version I'm guessing.

So based on the new info of the system lean bank 1 and the incomplete status of the evap system does that point to any new culprits guys?

Thanks!!!

Torque free does seem to be lacking when looking for live data for sure. It shows I can get data for Throttle but it never shows a value other than 13.3 and it shows it should have data for fuel trim but when I pull those up I get a static reading as well that never changes.

You want OBDFusion, it is a whopping $3.99.

If is far more intuitive to use than Torque and IMHO does a much better overall job and PROPERLY supports Wideband O2/Lambda sensors.

OBDFusion is what you want.

I monitored my 4.8l MAF reading.

About 9 g/s at warm idle in drive, about 6 g/s at warm idle in park.

3.5 g/s for a V8 is far too low.

Either sizable intake air leak after the MAF or a MAF that is way under reporting.

If you cleared all the code prior to rescan and you have that evap incomplete, it just means that you haven't driven the X far enough since you cleared the code. Our EPA test will fail any car with an incomplete since they know that any code must have been cleared prior to bringing it in for testing. Drive the X for a while (usually 50 miles along with a couple of restarts) and the evap incomplete will change to evap complete.

As far as the limitation of the free Torque, I am able to see data on both banks on my phone which have a free copy of Torque. I would suggest that if you have another car, scan that car with your Torque and see if you see all the data for both banks. Could be you have a bad copy of Torque or perhaps that is why your X has a problem. Could be the 02 sensors is not providing a signal to the DME and that is why it is not shown on Torque and why your car is not in a close loop.

Quit screwing around. OBDFusion for $3.99, slightly more than a gallon of gasoline.. Then Log the OBDII data stream. A Log will save about 10-20 replies in a thread.

So I finally had some time to work on the x again today and I found it.

The Oil sipstick downtube separated at the joint halfway down. I could see caked oil residue in the joint. I cleaned everything up snapped it back. cleared my codes and started it up and went for a drive.

The e53 runs and Idles perfectly now. The vacuum leak was in the dipstick downtube.

I've also replaced the airfilter after you guys mentioned the MAF readings were low and those readings are higher now as well.

Thanks again for all the help.

I'm off to dump the oil and do a rear brake job now. I love this fall weather for working on the cars

Glad you were able to get things sorted, but you still should purchase OBDFusion. Just because there are no lights on, does not mean everything is operating correctly. Additionally you could easily learn how to properly use the App and benchmark the values on the engine now so you know what "normal" values are for future reference.