Old thread update... my truck continued to occasionally produce blue smoke as described previously. Did notice it was predominately coming out of the driver's side tailpipe. I had the dealer check it several times to no avail and they couldn't replicate the problem. Finally now with 77k miles it did it when they started it up in the service department getting ready to do an oil change. I left it with them and they took down the exhaust, scoped the turbos and diagnosed it as a leaking turbo oil seal on the driver's side. Since it was out of factory warranty of course it was denied... Thank goodness for once in my life I had purchased the 'Works' Ford 5 year/100k extended warranty. It was covered and the turbo was replaced. Been driving it for about a month now and so far no more blue smoke (crosses fingers).