[Costello]

Car: N55 E92 NO MODS
New spark plugs, coils, injectors.
Correct 6-cylinder compression
eEror shows oxygen rich mixture in cylinder 4
The errors is not constant, it only occurs randomly.

After a repair of the Valvetronic at an official BMW dealer in Germany, I have the problem of having random misfires in cylinder 4:

https://www.e90post.com/forums/showt...5#post30981305

The problem is still being analyzed by BMW; but due to the lack of knowledge they are showing, I open the post in case anyone has any more ideas.

Considering that all the typical things that can cause misfires have been changed, what other options are left?

Thanks

[Cloverdale]

Unless you can perform your own repairs and maintenance these vehicles outside the warranty coverage aren't practical (as you've discovered). You should avoid anything turbo charged going forward.

[Costello]

Originally Posted by Cloverdale

Unless you can perform your own repairs and maintenance these vehicles outside the warranty coverage aren't practical (as you've discovered). You should avoid anything turbo charged going forward.

As everything in this life, it is better if you do it yourself. Unfortunately, not all of us have the time to do it and sometimes we have to outsource it to professionals.

[gbalthrop]

Originally Posted by Costello

Car: N55 E92 NO MODS; New spark plugs, coils, injectors. Correct 6-cylinder compression
eEror shows oxygen rich mixture in cylinder 4 [Please explain that in DETAIL: I'm NOT aware of HOW any measurement of AFR in ONE cylinder is possible (as opposed to One "Bank" or 3-cylinder Exhaust Manifold). "Oxygen-Rich" would be LEAN fueling (NOT enough fuel for air admitted).]
The errors is not constant, it only occurs randomly. After a repair of the Valvetronic at an official BMW dealer in Germany, I have the problem of having random misfires in cylinder 4:
https://www.e90post.com/forums/showt...5#post30981305
[I do NOT see any Fault Codes, Live Data, or other DIAGNOSTIC Data in the thread you linked, or HERE. What DME fault codes are "Currently Present"? Can you attach any Scans of Invoices which state WHAT was done & findings?]
The problem is still being analyzed by BMW; but due to the lack of knowledge they are showing, I open the post in case anyone has any more ideas. Considering that all the typical things that can cause misfires have been changed, what other options are left? Thanks

You have an "Intermittent" misfire?
ALWAYS Cylinder #4?
What Fault Codes are currently-present?
What does the Freeze Frame data for any Fault Code show as to engine conditions at moment Code Saved?
RPM, Load, Engine Temp, etc. can offer "Clues" of cause of "Misfire, as well as HOW to test (e.g. if happens at LOW RPM).
Can monitor "Rough Running"/ Laufunruhe as Live Data to see WHEN occurs.
Same Code(s) BEFORE changing Coil, Plug, Injector? Always Cylinder #4?

Testing wiring/ connectors for intermittent faults is difficult. Some "Misfire" conditions will shut off an injector (different Code or Fault Details when that occurs, & rough running due to NO Injector function on that cylinder. Less significant "misfire" does NOT cause Injector ShutOff.

Most $hop$/ Techs/ Mechanics are better at R&R (Remove & Replace Components) than DIAGNOSIS. It takes Time, Thought, Analysis, Knowledge of HOW systems work, etc. to diagnose. Even in Germany, I doubt the folks who have "analyzed" your vehicle have the SAME qualifications as those who designed it, and those who developed INPA, ISTA, etc.

Simple concept: If you have "Swapped" all COMPONENTS & Tested Compression, the "still-existing" cause of issue is something your "Experts" have NOT tested/ changed/ Repaired. After charging YOU for replacing many components, without actually "Fixing" the issue, it does NOT seem realistic to expect those "Experts" to ever tell you: "It was just a wire between DME & Injector".

BTW, was there anything done "under the hood" just before the issue began? If intermittent "Misfire" only occurred AFTER VVT repair by dealer, I would look/TEST for a wiring fault, such as pinched wire, caused by that VVT Repair.
George

[gbalthrop]

Originally Posted by Costello

As everything in this life, it is better if you do it yourself. Unfortunately, not all of us have the time to do it and sometimes we have to outsource it to professionals.

Quite True! When "Outsourcing" one has to have a "Well-Calibrated BS Meter" to determine the "Level of Professionalism" of the "Outsourcee".

DJT is NOT the only BS-Artist engaged in "Self-Promotion" & "Over-selling" his abilities. Some Basic Understanding of the subject matter, "Cross-examination Techniques" and Cynicism/ Correct understanding of Human Nature is necessary to calibrate that BS-Meter.

BTW, use of initials above has NOTHING to do with "Politics". It has MORE to do with a Case Study of "Abnormal Psychology", using someone who is "Universally Observable". Every reader is free to make his OWN conclusions.
George

[Costello]

Originally Posted by gbalthrop

You have an "Intermittent" misfire?
ALWAYS Cylinder #4?
What Fault Codes are currently-present?
What does the Freeze Frame data for any Fault Code show as to engine conditions at moment Code Saved?
RPM, Load, Engine Temp, etc. can offer "Clues" of cause of "Misfire, as well as HOW to test (e.g. if happens at LOW RPM).
Can monitor "Rough Running"/ Laufunruhe as Live Data to see WHEN occurs.
Same Code(s) BEFORE changing Coil, Plug, Injector? Always Cylinder #4?

Testing wiring/ connectors for intermittent faults is difficult. Some "Misfire" conditions will shut off an injector (different Code or Fault Details when that occurs, & rough running due to NO Injector function on that cylinder. Less significant "misfire" does NOT cause Injector ShutOff.

Most $hop$/ Techs/ Mechanics are better at R&R (Remove & Replace Components) than DIAGNOSIS. It takes Time, Thought, Analysis, Knowledge of HOW systems work, etc. to diagnose. Even in Germany, I doubt the folks who have "analyzed" your vehicle have the SAME qualifications as those who designed it, and those who developed INPA, ISTA, etc.

Simple concept: If you have "Swapped" all COMPONENTS & Tested Compression, the "still-existing" cause of issue is something your "Experts" have NOT tested/ changed/ Repaired. After charging YOU for replacing many components, without actually "Fixing" the issue, it does NOT seem realistic to expect those "Experts" to ever tell you: "It was just a wire between DME & Injector".

BTW, was there anything done "under the hood" just before the issue began? If intermittent "Misfire" only occurred AFTER VVT repair by dealer, I would look/TEST for a wiring fault, such as pinched wire, caused by that VVT Repair.
George

Unfortunately I do not have more information than the one provided in the post. I will try if I get home this weekend, to connect the INPA myself and see the values.

Before taking the car to the dealer there was no problem of misfires, and they appeared after the repair of the valvetronic. Of course in the initial diagnosis of the car these errors were not present either...
Yesterday I received a reply from the BMW dealer, in summary, they told me that they have changed everything they think could be the cause and they do not know what the problem is, therefore they have escalated it to BMW AG, so someone from Munich will come here and do a more detailed diagnosis themselves.

Since it should not be forgotten, that the car was delivered allegedly repaired and the invoice was already paid.

My suspicions about the cause of the problem are: some damaged wiring, damaged DME, wrong coding of the new injectors...

[Costello]

Originally Posted by gbalthrop

Quite True! When "Outsourcing" one has to have a "Well-Calibrated BS Meter" to determine the "Level of Professionalism" of the "Outsourcee".

DJT is NOT the only BS-Artist engaged in "Self-Promotion" & "Over-selling" his abilities. Some Basic Understanding of the subject matter, "Cross-examination Techniques" and Cynicism/ Correct understanding of Human Nature is necessary to calibrate that BS-Meter.

BTW, use of initials above has NOTHING to do with "Politics". It has MORE to do with a Case Study of "Abnormal Psychology", using someone who is "Universally Observable". Every reader is free to make his OWN conclusions.
George

You are absolutely right, I went to the local BMW workshop because it is one of the largest in bavaria, because many local workshops told me they did not do valvetronic repairs and the indie ones that did, charged the same as BMW.

After the experience, it was without a doubt the worst decision I made.

[Cloverdale]

Originally Posted by Costello

You are absolutely right, I went to the local BMW workshop because it is one of the largest in bavaria, because many local workshops told me they did not do valvetronic repairs and the indie ones that did, charged the same as BMW.

After the experience, it was without a doubt the worst decision I made.

Going forward, the maintenance and repair requirements on these complex vehicles will continue. Consider moving on from it if you're going to have to be dependent on professional assistance.

[Costello]

UPDATE: An engineer from BMW Germany checked the car and made different logs, a Walnut Blasting was tried, and this did not improve the problem.
After this, they told me that they suspect that it could be the Roller drag lever and the Intermediate lever of cylinder 4.
Next week they will try swapping the cylinder 4 lever with cylinder 1 to confirm if this is the cause of the problem.

So far all this is not having any extra cost for me, however, shouldn't the problems have occurred before the valvetronic repair?