2005 ford e350 with 202000 miles. It is a mini bus and i changed the oil about 2 weeks ago. i dont know which weight of oil was in there prior but i changed it to 5-20w and i seem to get a small puff of blue smoke on start up. it goes away. then when the van is warm on take off sometimes it blows out blue smoke. I sat in traffic a while today and after five min of long idling when i take off it will blow a bit of a cloud then it would go away. changed the pcv valve already. do you think i should be using 10 40 or 10 30 weight?

 

as you already know, it appears to be burning oil. a heavier oil would probably slow this down, i would suggest adding a bottle of a thick additive such as STP oil treatment to thicken it up a little, and that should slow down how much oil it burns. next time you get around to changing the oil, something a little heavier would probably help

 

ill probably get around to changing it tomorrow. and then ill post updates thanks!!