Misfire code?

2012 BMW X5
145,000 MILES • 4.4L • TURBO • 4WD • AUTOMATIC
Avatar
BHAMDOC1
  • MEMBER
  • 364 POSTS
Starts fine when cold. Leave it few and it misfires on cyl 5 which i assume is on front of driver side. Changed coil and spark plug. Same thing takes few minutes before it misfires from cold. Scanner shows a history of all cylinders misfire at some point but cyl 5 in the 32000 compared in the thousands for others. Engine is smooth until this misfire of cyl 5 happens. Delete it even when warm its fine till it misfires again.
Images (Click to enlarge)
Attached Media
Attached Media
Oct 1, 2026 at 1:06 PM
Advertisement
Avatar
BHAMDOC1
  • MEMBER
  • 364 POSTS
Also the only code is a misfire on cyl 5. No smoke when u first start it and the plug was not wet so i doubt a leaking injector
Oct 1, 2026 at 1:34 PM
Avatar
BHAMDOC1
  • MEMBER
  • 364 POSTS
Some videos. Drove it in front of my home after deleting the code and it drove nice and strong. It randomly does it sometimes after 3-4 minutes sometimes 30 seconds after start
Videos (Click to enlarge)
Attached Media
Attached Media
Oct 1, 2026 at 4:13 PM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,433 POSTS
You have found the problem, when you release the oil cap, the vacuum is too high, this is because the check valve for the Positive Crankcase Ventilation system is blown. This will cause the misfire codes. Here is the part you need to replace to fix the issue.
Image (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Oct 1, 2026 at 6:55 PM
Avatar
BHAMDOC1
  • MEMBER
  • 364 POSTS
And I am guessing there are 2 of them?
Oct 1, 2026 at 6:56 PM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,433 POSTS
Yep, one for each cylinder bank.
Oct 1, 2026 at 7:04 PM
Avatar
BHAMDOC1
  • MEMBER
  • 364 POSTS
Thanks
Oct 1, 2026 at 7:05 PM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,433 POSTS
Np, let me know how it goes.
Oct 2, 2026 at 7:06 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.