E90Post
 


The Tire Rack
 
BMW 3-Series (E90 E92) Forum > BMW E90/E92/E93 3-series General Forums > General E90 Sedan / E91 Wagon / E92 Coupe / E93 Cabrio > Wrong fuel. Misfire on cylinder 6. Missing O'ring on fuel injector



Reply
 
Thread Tools Search this Thread
      Yesterday, 07:16 PM   #1
DoomedE90
Registered
0
Rep
1
Posts

Drives: E90 BMW 335Xi
Join Date: Sep 2024
Location: Florida

iTrader: (0)

Unhappy Wrong fuel. Misfire on cylinder 6. Missing O'ring on fuel injector

I bought an e90 N55 335xi this year and I kept my daily. About a month ago I was fueling and I put 87 in it instead of what it’s tuned for (93)- without thinking that it's NOT the daily!!

The car started misfiring a bit. I could hear it burping clearly. Fast forward and talking to the guy that tuned it (stage 2+) on what I should do, he recommended I refuel it with E85 when I get to half tank. Then run that tank and all should be good. So, I put in 4 gallons of E85 and then topped it off with 93 (came to be another 4 gallons to top it off). The misfiring got worse the more I drove it and the engine light finally came up, misfire on cylinder 6.

We drained the tank and put new sparks. I drove it for over 100 miles and the car still misfires.

We pulled out the fuel injectors and the one in cylinder 6 was missing it’s O-ring. It is worth mentioning that when we took the injectors out we were surprised that "Mr Trusted Mechanic" (the guy that tuned it) did not install the decoupling elements when he replaced the injectors last year (2023)!!

We borescope it and nothing was inside the cylinder so we just replaced all injectors in hopes that everything will go good. The car still misfires, same code after less than 10 miles!! What should I do?

I just cannot wrap my head around these questions:
1- How did the car run for a little while when the injectors were installed with no decouplers with no issues?
2- How would the wrong fuel cause much more damage than the injectors sitting inboard?
3- Where did the O-Ring disappear?
4- What could be the issue now? I replaced all injectors but it is still misfiring!
Attached Images
   
Appreciate 0
      Today, 10:23 AM   #2
lookalikehuuh
Major
United_States
924
Rep
1,439
Posts

Drives: 2006 330i, 2007 335i
Join Date: Sep 2014
Location: San Diego, CA

iTrader: (0)

Its pretty likely the injector holes are out of round now and aren't holding pressure properly, causing the misfire. This happens because the decouplers are missing and the injector essentially bounces around in the head and ovals it out. Sounds like Mr. Mechanic will need to replace the head for you.

There is a company that makes threaded inserts, but they are apparently somewhat problematic from what I have seen. So replacing the head is the correct way to fix the issue.
Appreciate 0
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 08:25 PM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST