BMW X5 Misfire Part 1

[PineHollowAutoDiagnostics]

Ramon! I had the exact same thing happen on an X5! IT STUMPED ME! With the MAF unplugged it ran beautiful, just Check Engine light on. So the customer just left it unplugged xD. One of the only cars that I gave up on...

[DTEAuto]

my suggestion before going any further would be to definitely inspect the crankcase ventilation system, if the diaphragm tears it will "leak internally" and you wont see it in the smoke test. This will cause lean mixture codes always and cause misfires to be present and erratic engine idling/operation. I personally have also seen it cause mass airflow sensor codes to be present, which might explain the signal you were seeing. The quickest and easiest "crude" but effective test would be to have the engine idling and unscrew the oil cap and pull it off, if the valve diaphragm is torn bad it will introduce manifold vacuum to the crankcase and it will make it very difficult to pull the cap off and you should hear it "hiss" real loud and sometimes stall it its a big leak. since you stated in one of the comments that you have a second x5 outside, do the same test and compare the two. if its not a full blown diaphragm tear but minor, you can check the crankcase pressures with the scope like you did on your other video, the spec for that m54 engine stated by bmw is 16mBar (.47inhg) and can vary up to + or - 10% but not more than 5mBar. I took a factory oil cap and drilled it and put a fitting port on it and always check it there and one of the first things i do, especially this time of year when it gets cold its very common to have the moisture freeze up and tear that valve internally. hope this helps or gives you some direction, hard to know what the issue is not seeing it in person but id like to see you not stress any further if its a simple quick test you could do to find a possible issue. and thanks again for all the videos you make and put out with great information

[EXOVCDS]

Great use of those coil bars again... I really need to make some! =)

[richardkahl]

Those lean numbers suggest un metered Air. The Pcv systems can cause large lean numbers, Also crankcase leaks such as front or rear crank seals. To Check the pcv system use a manometer and measure amount of vacuum out of oil cap. Use your propane at the front or rear crank seals and watch your trim numbers. Hope this helps

[billmck]

great case study you have going on....did you take a fuel sample and what does the fuel guage read....

[haywardsautomotive]

Nice video Ramon. Looking forward to seeing what you do to fix this issue. MAF was over reprting needing further testing and noticed on snap throttle @19:39 #326 MAF 280 Kg/h B1S1 read.690 (O2 sensor not cycling full lean/rich so .690 was actually max) B1S2 .830 (Rich on snap throttle so normal response) however B2S1 .020 & B2S2 .100 (Stayed lean abnormal response) & then at 19:40 #327 MAF 33.75 B1S1 .18 B1S2 .02 (normal response lean) B2S1 .00 B2S2 .01 (Lean expected) so also curious to injector PWM & intake runner status. Curious of throttle blade % at idle along with the MAF reading. PCV could be an issue but does not coincide with MAF unless as suspected it's over reporting. Interesting case study Ramon so hurry up and fix it & post the video :D Good luck my friend!!

[jeffreyherbert]

Hi ramon the maf reading was very high early in the video when the misfire and or cylinder shut down occured 12gs i think later at 16mins in when running ok was showing 3.75 gs i worth a this vehicle have an egr? Maybe maf over reporting intermittently or egr valve sticking intermittently and giving incorrect flow indication through during the video the maf reading is shown in g/s in generic but kg/h when non generic ( 13kg/h is 3.6 g/s i think ) I agree with super mario a VE test would be interesting

[jgeorges]

Ramon, awesome/excellent always learn some thing from ur video what is VE test and should the maf sensor be reading +/- 20% i mean if the engine is 2.0 LT that suposed to be 20% more or less.

[upallnight]

If your scanner can show misfire count, see how many misfires the computer count before it shut down the injector. A misfire to a computer control engine means a cylinder is not producing the same amount of power as the other cylinder. This could be due to a weak cylinder (lower compression) or a lean cylinder (Less gas, dirty injectors or weak injectors).

[DmitriyL_Arithmechanics]

Hi Ramon, can't wait for the update. It seems to happen often that the MAF is suspect, but not conclusively. I'm wondering if there is a way to reliably benchtest MAFs... something made with a leaf blower and a known good MAF, perhaps?

[speralta]

Could certainly still be a bad MAF. However, I'm doubting it because the additive and multiplicative values (Fuel trim 2 - idle load and part load on your Verus PIDs) at 19:37 didn't appear to be contradicting each other. Hopefully that's wrong and it does turn out to be a bad MAF.
Another place to maybe take a look at would be the crankcase vent system. That could be a source of unmetered air giving you lean conditions like your seeing. Looking forward to the update!

[stevepark]

I would set the injector shut down aside until the primary cause of the lean condition is corrected. That is easier to do under load. I would graph MAF and MAP and both front sensors on a WOT, 0 to 1-2 shift, run. Then look to see if the MAF is skewed. Rule of thumb is G/s = 80% of rated HP. Then check MAP and TPS and O2 sensors readings. That should give direction of the too much air or not enough fuel question.

[carstengotfredsen]

Hi Ramon. Have read an article where a defective rear ABS sensor/ring made a mistake,
then the anti-spin system entered and closed a nozzle, to reduce engine power.

[SuperMarioDiagnostics]

I didn't like that over reporting maf. How about a VE test? Anyway great video Ramon. Love the process, and love that signal generator! 👍👍👍

[abdullbasitosman]

which picoscope model you used ? 2204 a ?

[autorings]

Ramon, very common on this model the PCV leaks internally, I was surprised you did not check the fuel pressure and how much current the pump is drawing, keep up with good videos

[power]

OUTSTANDING CONTROL OF THE PICO SCOPE, I AM CONTINUING TO ASK TO PLEASE IF I MAY BE GIVEN THE OPPORTUNITY TO PURCHASE AN IGNITION WOUND . I DON'T JUST WON'T IT I TRULY NEED IT . I APPRECIATE YOUR CONTENT AND AM LOOKING FORWARD TO YOUR REPLY THANKS SO MUCH MY FRIEND .

[javaidmalik]

This happen with me on x6 15 days I work every day new things at I changed eccentric shaft sensor and maf it's become ok