6.0L blowing blue smoke. NEED HELP!!!

[coal pusher]

Hi guys,

I just bought a 2003 F-350 with the 6.0L in it. It has 188,000km's on it and it is bone stock. Its a 6 speed standard. Not all the time, But the odd time in 2nd and 3rd gear once i hit around 2500rpm, it loses power and blows blueish white smoke out the exhaust. I have a few ideas of what it might be but im not 100 percent sure.

Looking for some input on what it may be.

Thanks