Misfires after filling up

[dennisvab]

My wife filled up at Speedway and drove around for say 10 miles and later parked. When trying to start up again later in the day, the SUV immediately went into limp mode.

EDIT: 2011 BMW X5 with N55.

After scanning it i came up with these codes

-2FAC: Ignition, Cylinder 5: Combustion period too short
-2EFE: Combustion misfires, several cylinders detected
-2F03: Misfire, Cylinder 5: Detected
-2EE0: Misfire, several cylinders: Fuel Injection deactiviation
-2EF1: Misfire, Cylinder 5: Fuel Injection deactivation
-2EE2: Misfire, several cylinders: damaging exhaust gas after starting up
-2EF3: Misfire, Cylinder 5: Damaging exhaust gas after starting up

It seems that 5 is the only one misfiring, but it is telling me others are as well. I have swapped a few coils around and even spark plugs, but i get the same codes back. Can it be bad gas? I have already put in a bottle of Heet in https://www.walmart.com/ip/ISO-HEET-...eaner/16879747

[AlphaBetaX5]

Originally Posted by dennisvab

My wife filled up at Speedway and drove around for say 10 miles and later parked. When trying to start up again later in the day, the SUV immediately went into limp mode.



After scanning it i came up with these codes



-2FAC: Ignition, Cylinder 5: Combustion period too short

-2EFE: Combustion misfires, several cylinders detected

-2F03: Misfire, Cylinder 5: Detected

-2EE0: Misfire, several cylinders: Fuel Injection deactiviation

-2EF1: Misfire, Cylinder 5: Fuel Injection deactivation

-2EE2: Misfire, several cylinders: damaging exhaust gas after starting up

-2EF3: Misfire, Cylinder 5: Damaging exhaust gas after starting up



It seems that 5 is the only one misfiring, but it is telling me others are as well. I have swapped a few coils around and even spark plugs, but i get the same codes back. Can it be bad gas? I have already put in a bottle of Heet in https://www.walmart.com/ip/ISO-HEET-...eaner/16879747

It can be a bad gas that triggers a weak component to go bad in your engine. I have gotten somehow similar experience.

By bad gas i mean non-top-tier-91-octane-rating! Costco!!

Add a bottle of Techron injector cleaner and monitor it along with your troubleshooting.





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[AlphaBetaX5]

Also look at the receipt, was the gas 91 octane rating?

If not, the gas is the root cause.


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[pshovest]

Wrong octane is not the problem.
Which year & engine?

[andrewwynn]

I had an identical experience. I was convinced the pump (one with one hose three grades) just filled with 87 v 93.

Turned out to be a coincidence. It's probably a bad coil in my case. Timing was just coincidence.

[dennisvab]

Originally Posted by pshovest

Wrong octane is not the problem.
Which year & engine?

I apologize, I inferred my info was a signature. It’s a 2011 BMW X5 with the N55.

[dennisvab]

Based on the N55 code list that can be found here (http://www.1addicts.com/forums/attac...2&d=1317300396) it seems that it’s either the spark plugs or the coils. Other issues could be a bad harness which I have thought about replacing since I have one laying around.

Could it be a hpfp issue? Or possibly an injector? I can’t say any of the spark plugs that I have removed smelled like fuel.

[pshovest]

I know the N54 injectors are problematic. I've had 9 injectors replaced under warranty in my E60 in the first 45k miles. Not sure if they've fixed this with the N55 injectors. Looks like you've moved the coil & plug and cyl 5 still misfires. Sounds like injector is bad.

[ard]

It is NOT the octane.

It is almost surely NOT the plugs or coils (they don't all go bad at once, causing multiple misfires)

bad gas is exceedingly rare. THink about it, 20% of the time were are within a day of a fill up.... If your wife said "I went to the grocery store" you wouldn't think 'maybe it was the groceries'. ( )

I believe some of those codes are actually 'misfire with cylinder deactivation due to dangerous lean conditions'. (When the AFR is too lean the spark is deactivated to Brent damage.

So in that, maybe a clue? Any chance you have a failing fuel pump? Not getting enough fuel pressure will give you all the codes you see. That's were I'd look.

(And watch, this will be the one in 100,000 bad gas events...)

[dennisvab]

Thanks for the feedback folks. It ended up being a bad injector in cylinder 5. I have 6 injectors laying around, I replaced with one of those. I haven't coded in the adjustment value yet, but as of right now it runs great.