Persian_535i

Yeah that's a ridiculous amount of work and something I won't be doing lol.

Persian_535i

Found a huge thread regarding this issue, many people used carb cleaner/brake cleaner and brass wire brushes.
Gonna hit up autozone and get some brushers and cleaner, I can already tell this is gonna suck.
DIY-Intake Valve Cleaning - Page 3 - N54tech.com | BMW N54 N55 135 335 535 Turbo Performance Forum

Persian_535i

Started cleaning my valves today, four of the six valves are closed and two are open. Anyone know how to get the two open valves to close with an automatic?

baveagle

Check page 36 of PDF attached to post #10 by Shydee

Persian_535i

Good eye, its $15 at AutoZone gonna go grab one. Will save a good hour atleast not having to remove lower plastic shield, fan, and having to wrench the pulley by hand to open/close valves.

Happy to say I also got my LPFP in the mail today, gonna install that as well. Hopefully everything will be done in the next day or two (being lazy) and I'll post whether the misfire symptom went away or is still around.

Persian_535i

RESOLVED: After changing replacing spark plugs (53k miles needed to be done) LPFP sensor replaced (which needed to be changed anyway because of code thrown) and cleaning the valves (needed to be done, dirty as sh**) the misfires were still occurring. I finally was at a loss and decided to take the car to the dealer. They ran a diagnostic which I already had the codes spent $89 on that, the SA told me the tech has to do everything step by step. Since the plugs and LPFP sensor were already changed, he would have to check the coils next, then the injectors, then the fuel pump in that order. So next on the list was coils, he suspected the coils were bad, the dealer quoted me around $978 for parts and labor for the coils. I told the SA that I didn't want to spend a ton of money with a wedding around the corner and that I'd do it myself (it's literally a 15min job). He was nice enough to let me use his employee discount so I got each coil for $40 instead of $68, all together the bill came out to $260ish with tax and $89 for the diagnostic. I came home and replaced all 6 coils in 15mins and the misfire is gone. I don't want to say 100% that everything is resolved because I haven't had the opportunity to actually drive it around, but the car started without the nasty noise and the shakes and no check engine light so it is looking positive.

Summary: It was the Coils!

AchtungE60

Fuel, Air, Spark.

Always clean air intake out and filter
Change spark plugs every 30K or so
Fuel - you can alternate it doesn't matter

If you had rough idle issues, I would have checked the air first and spark second. It's very easy especially when you can buy coils at auto store and test to be 100% sure first.

Persian_535i

Drove the car all day today and no issues my specific issue ended up being malfunctioning coils. Very very simple diy compared to the intake manifold carbon cleaning... that was a pain.