I recently replaced the ignition coils and plugs on my 2009 R56, N12 engine (160k miles). Now that I've gone back to do a valve cover gasket replacement I ran into an issue where the boot on the bottom of the coil detached and got stuck so badly to the spark plug that I destroyed the boot in the process of removing it (see pictures). The new coils are Delphi GN10328. I also noticed when installing them that the same part number yielded different style coils (in the same Delphi box I will add). Take a look at the pictures I have attached.

I'm no idiot and used WD-40 as well as long needle-nose pliers to try to get to boot off the plug. It ended up taking multiple picks and the pliers to finally get it off. When I had the plug out of the car I tried connecting the other (good) coil to the plug outside of the car and when I pulled the plug, the boot came off (this happened if I greased the plug too).

Basically, I don't want to put the car back together if I am going to end up in the same situation. When the boot comes off there's no way to remove it and you can't pull the plug with the boot stuck there (trust me, I tried that too). If I didn't have the valve cover off, there's no way I would have gotten the boot out either.

Do I try to bore out the boot a bit? Axle grease the boot (I just used some motor oil in my "out of the engine" test)? Is there a different part that I need to get (the Delphi's seem prolific and I like the way the plug "snaps" into the coil".

Any help is appreciated. Thanks in advance!


Delphi coils with same part number, completely different construction.

Coil on the right had boot separate from coil and I couldn't for the life of me get it to come off the plug.

Close up of destroyed boot.

 

@trwelling ,

My best suggestion to prevent from ever happening to you again is to lather lithium or di-electric grease on the porcelain of the spark plug as well as running your fingers inside the boot with grease. Don't use WD-40 as it would deteriorate the rubber boot overtime and it won't stay lubricated therefore rendering difficulties of removing the coil pack in the future.

 

@Vanski Thanks! The di-electric grease worked! I had tried lithium and axle grease but they didn't do the trick. When I returned the two coils for new ones (Autozone did right by me) the new coils had dielectric grease in the boots. The previous coils I bought didn't, so now I know! I'm still surprised at the different styles of coils with the same part # from Delphi, but who knows...