Hi my 04 tdci 2.0 (130ps) has starting to play up for about a month now, in some cases i found it nearly impossible to start so i went out brought a brand new battery and starter motor and all was ok for about a week! then i started to notice that i was losing coolant so i took it straight down to my local garage to look at and they said that there was nothing wrong. it only does it when its cold as soon as i turn it over it would be fine for the rest of the day,so i carried on driving it and now its getting a lot worse i notice twice last week it was smoking white smoke for a bout 5 mins then it would disappear. so i went to my local ford garage today to find out what they say and they said they cant find nothing wrong with it they done head gasket test, compression test checked for water leaks nothing they said there next step would be to remove the head and investigate further at a cost of around 900 that's just to diagnose it!
please help if anybody has had this problem or no what it might be!

videos
starting problems:
http://www.youtube.com/watch?v=vSDFmuLjukY
white smoke:
http://www.youtube.com/watch?v=6QCHwanGy3w