Well my time with Z4 's has come to a rather sad end after 6 years. They did a compression test and there is none on cylinder three and also no end to the spark plug that is now somewhere in the engine. My garage has advised a new engine and this has effectively written off the car which was probably worth about £5K.
I can't afford another car at present so it's the electric bike and train for me.
Thank you to all your help over the years, it has been greatly appreciated.
Adios
Nick