[analbumcover]

Cross posting from the e70 forums for more visibility and help. Thanks in advance

hi all - recently bought a 2011 X5 w/ the N55, 80k mi. Doing preventative maintenance and successfully replaces plugs 1 through 5 (the coils got progressively more rusty as I moved towards the firewall).

Anyway, plug 6, stuck. Soaked in penetrating oil over night then I slowly walked it out and get the plug removed but the washer was still in the cylinder head...odd. Fished the washer out and then went to look at the plug I just removed and half the threads are smushed.

Here's a pic of a good used one and the one I pulled.

View post on imgur.com

Thoughts on a solution? I can get a new plug into the hole and started about 1 revolution before there's resistance.

[wheela]

Sorry to see this. The plug threads aren't smooshed, they have aluminum from your cylinder head's threads all caked in them. Not sure what you can do to try to repair without pulling the head off? It would seem that anything you try with the head still on would risk dropping aluminum particles into the cylinder?

[analbumcover]

Originally Posted by wheela

Sorry to see this. The plug threads aren't smooshed, they have aluminum from your cylinder head's threads all caked in them. Not sure what you can do to try to repair without pulling the head off? It would seem that anything you try with the head still on would risk dropping aluminum particles into the cylinder?

so I thought that was the head material too but I've tried chiseling out the "shiny threads" on the spark plug nothing budges, its all the same material. If you follow the spark plug threads closely, it looks like they just folded over.

I'm grabbed a back tap in 12x1.25, planning to tear down the valve cover and spark plug/injector recess so I am only a few inches from the actual head/plug hole. From there I'll use the back tap to start from inside the cylinder and hopefully straighten out the threads...

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1


Any other creative ideas? trying to avoid head removal/replacement...

side bar - did I cause this on removal or was this damage done by the prior owner?

[wheela]

Originally Posted by analbumcover

so I thought that was the head material too but I've tried chiseling out the "shiny threads" on the spark plug nothing budges, its all the same material. If you follow the spark plug threads closely, it looks like they just folded over.

I'm grabbed a back tap in 12x1.25, planning to tear down the valve cover and spark plug/injector recess so I am only a few inches from the actual head/plug hole. From there I'll use the back tap to start from inside the cylinder and hopefully straighten out the threads...

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1


Any other creative ideas? trying to avoid head removal/replacement...

side bar - did I cause this on removal or was this damage done by the prior owner?

Wow, I've never seen one of those tools before. I can't comment on that tool as I've never used it, I wonder if anybody here has some experience with it? If it was my snowblower I'd give it a shot, but I'd be pretty nervous using it on my n55. As a side note, if that is aluminum from the head on the sparkplug like I suspect, you probably will not be able to pick it off the plug, as it's galled on there (essentially bonded to the plug threads).

[glocknick]

Originally Posted by analbumcover

so I thought that was the head material too but I've tried chiseling out the "shiny threads" on the spark plug nothing budges, its all the same material. If you follow the spark plug threads closely, it looks like they just folded over.

I'm grabbed a back tap in 12x1.25, planning to tear down the valve cover and spark plug/injector recess so I am only a few inches from the actual head/plug hole. From there I'll use the back tap to start from inside the cylinder and hopefully straighten out the threads...

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1


Any other creative ideas? trying to avoid head removal/replacement...

side bar - did I cause this on removal or was this damage done by the prior owner?

Try to repair the threads with that tap. It may work enough to get a new plug in. I'd try to timesert it next if you can't clean up the threads.

[analbumcover]

good news, back tap worked. I had tons of thread at the bottom of the spark plug hole for the tap to use. New plug when in by hand and I torqued it down. For anyone doing this, you have to have SOME good threads for it to work. I had to make the back tap as small as possible to even get it to fit all the way into the piston/head. you also HAVE to take the cylinder/injector recess out so that you can get the angle right. here's a pic

View post on imgur.com

What you'll also see in the pic is the fuel injector with its top snapped off because F$%^& rust. So, one problem solved, another created. I even used the damn tool and everything.

[wheela]

Awesome news, thanks for following up! Any thoughts on where all the water came from? I've read water in this area can happen when people do cowl deletes.

[analbumcover]

the cowls were half broken when I bought the car 1k miles ago. Guessing this was the reason for the rust. I also think the factory or the prior owner (plugs looked original) didn't install the plug correctly.

[analbumcover]

just to close the loop on the fuel injector being stuck and to hopefully help anyone in the future.

the solution was cutting new threads M7x1.0 onto the injector stem. I kept cutting until I got half way down and stopped w/o backing up the die (really gets the die to bite in). From there, slide hammer-vice grip dealio (Astro Pneumatic Tool 78415). Locked onto the die and a few slides later it popped out. I also soaked the injector in liquid wrench penetrating oil and hand a helper hold the vice grips still while I went HAM on the slide hammer part.

View post on imgur.com