Further to the recent thread on 'K Series Let Go', which I have just read with increasing levels of anxiety, my 1.6 K series engine has developed an unusual noise from the exhaust side during the Croft Trackday. I thought I had cured this by the simple expedient of removing the heat shield which I'd wrapped round the starter motor. Flushed with success I took the car round to my pals who had also witnessed this noise at Croft. We both agreed it had gone. Sadly a couple of weeks later I started up to check her out for my last track day of the season at Knockhill to find the noise has returned. I then removed the starter motor and bump started down the drive - noise still present. I've had the cam cover off and spark plugs out - nothing untoward there.
My best description is it sounds like marbles bouncing on a tin tray coming from the exhaust side of the cam box. I have just received a copy of Rover K Series, Maintenace, Repair and Modification by Iain Ayre and Rob Hawkins.
However it would be good to get the opinion of our K Series experts before I go any deeper.