OK, I'm resurrecting an old thread but I've noticed a similar situation with my 147 JTDm 8v.
I bought the car at 1 year old and for the first year the car started fine, even in cold weather, even starting from cold, the engine only turned once before starting - regular as clockwork.
Since the summer I have noticed that the engine turns longer and longer before starting but only when starting from cold. This last week the engine has been turning 4-5 times before starting.
The 2 year service was done when it should have been. This problem started about a month to 6 weeks after the service.
Final info, approx 90% of journeys are short, under 5 miles. She only gets a longer run maybe once a week.
I originally thought the fuel filter might be the cause (even though it should have been changed during the service), didn't think about the glow plugs. I always thought glow plugs should last longer than a couple of years?
Any other ideas (or confirmation that it's the glow plugs) will be most welcome. I'm not sure if I should drop her into the dealer and explain, I still have 9 months warranty but not sure if glow plugs are covered by it.