I'm changing the spark plugs on my 01 S4 - have got the horizontal one out - the one under the radiator, and have put the new plug in fine.  Problem is I can't get the coil back on all the way - have spent an hour trying everything I could think of!!  The rubber coil 'boot' just wont go in!! 

Help!! 

Has the new plug got a threaded end - some plugs come with a removable round nut to fit a different type of spark plug cap.

Quote from: WTSDS on September 14, 2008, 05:08:37 AM
Has the new plug got a threaded end - some plugs come with a removable round nut to fit a different type of spark plug cap.

+1 you might need to remove the adapter that comes on some plugs.

What plugs are you using? Are you sure they're compatible? Have a look inside the plug connector to see if anything has shifted or broken, compare it to your other plug wire.

S4 coil needs to have the bare threaded stud on the spark plug.

+1 to what's been said already.  sometimes it take some force to get it off, just use some pliers to unscrew it.  your plug should look like this when you're done: