X5 cold start with raffle

[binbin93]

Hi everyone,

recently, my car 2007, X5, 3.0si has problem that when cold start the engine could not be started with big raffle in the engine compartment. then I have to push pedal gas a little bit during starting, it runs but big raffle still presents, raffle is out after about 5min engine running (hot). if I start engine when hot no raffle and no need to push more pedal gas.
please advise me what is problem of my car? is it from Vanos? or lube oil quality?

thanks for any ideal.