hey, i have a 2002 f150 4.6 4x4....lately it has been blowing out some blue smoke from the exaust when i start it... it also happens when im idling in traffic for a bit and then push the gas to move....any suggestions on what might be causing that...i really need to know if theres a possibility i might break down right away because i have a 7000 km drive ahead of me in 3 weeks.... thanks.

 

Oil leaking through the valve stem guides. Will gradually get worse.