[DJames007]

Hi everyone! I’m new to this forum so I’m not sure if I’ll get any responses, but I have a question about my N63 in my 2011 550i. I recently went through the process of replacing my valve stem seals, and of course also replaced all of the other related gaskets I could while I had the engine apart (I used the AGA valve stem seal gasket kit), as well as replacing all coil packs and spark plugs. I just started the car for the first time a couple days ago, and now I’m getting a bunch of misfires (I’m pretty sure it’s only running on 3 cylinders most of the time, I’m getting tons of misfire codes, and it’s not always the same cylinders misfiring either from what I can tell). I’m a little bit overwhelmed and I’m not sure where to even look first for answers. (I already checked the obvious stuff such as making sure the coil packs are all the way plugged in, all the wires are connected, etc.). So in summary, I could use any help I can get, because I really want the car to just work again because it took me like three months of working on and off to get to this point, and I’m only 16 and pretty broke. Thanks in advance for any suggestions!

[DJames007]

I forgot to mention in my original post, but I was already getting a misfire on cylinder 8 before I took the car apart to replace the valve stem seals, but I assumed that replacing plugs and coils would take care of it, but clearly not. Also, all cylinders hold perfect pressure when doing a leak down test, so I am pretty sure it’s not a catastrophic failure or anything. I haven’t done a compression test yet, but I will probably do that soon.

[Hornet-01]

check the injectors, and check all the places where you took it apart. As a rule, after assembly I connected something poorly. Also check for air leaks