My 2005 galaxy tdi is very hard to start from cold, I've done the usual thing to renew the heater plugs but still the same. It just turns over forever however when it does start it'll run all day until it has been left for a long period again sometimes if your lucky it'll start instantly but more often than not this is the procedure that I'm going through every morning. In the summer months it gives absolutely no trouble if this helps with the diagnosis