[threedirtyfi]

I ran into a weird situation when changing my spark plugs where i can't tell if the spark plug hole is crossthreaded or gunked up with carbon and I was wondering if anyone else has experienced the same. Bare in mind this is my first time changing a plug on an n54, but I'm not new to changing plugs in general and no other car has felt like this before.

In cylinder 5, when I was threading out the old spark plug with my finger tips on the socket extension after I cracked it loose, it would start feeling tighter at certain points where i needed to use the ratchet, then it would loosen normally for about 3/4 of a turn then feel tight again. This continued until I got it out. It wasn't stuck or anything, it came out like all the other plugs, which makes me feel like it isn't crossthreaded or stripped.

When I started screwing the new one in, again with my finger tips, it would start to get tight prematurely, then suddenly break loose. It almost feels like it's crossthreaded or I stripped a bolt, but at the same time I'm just using my fingertips, so I can't imagine damaging a thread that way even if i put it in at an angle. But I ended up threading it back out cos I didn't want to risk any damage, again it comes out completely normally.

There was quite a bit of carbon build up on the old plug. I couldn't see any shredded metal on either the old plug or new one i started to thread in.
So I was just wondering if anyone else has experienced this before? Am I just being paranoid and should just keep threading it in until it reaches the bottom?

The only thing I could find was a thread online for the n55 and everyone was saying that was normal for the way it came out, but they say it goes back in smoothly. (https://f30.bimmerpost.com/forums/sh....php?t=1755979)

Update: I decided to thread it in further, now it's reached a point were i needed to use the 3/8 ratchet to start tightening it, but it feels like it's on the verge on being stripped. Now i'm debating whether or not i should keep screwing it because I cant tell if its some carbon build up or it is cross threaded.

[39Xallday]

Sounds like carbon build up but I'd exercise extreme caution and when in doubt don't force it. Maybe run the old one out and in a few times to try and clear the gunk. You can get a boroscope/inspection camera quite cheap off Amazon or eBay that hooks up to your phone and look closer for thread damage or blockage. I use mine all the time and that would be my first move before proceeding.