I just traded for a 228k miles 2001 7.3 truck. It cranks decent and runs decent/well under load....turbo feels to be boosting properly...but at idle or light throttle it smokes blueish white smoke.....idles kinda rough also.....has great oil pressure and does not really seem to be lacking much in power.....plugged up ngs and only code i get is PO284, I think, it was late last night, but it says cyl 8 balance...what does that mean?..I personally have had a 99 with over 508k when i sold it so i wasn't too worried about the miles on this one ...but its got me concerned with the smoke and the code...please help thanks Rob 704-507-2453

 

Are no other codes are present? This is a mechanical problem: injector, compression.

 

Yeah, this doesn't sound very good. You could try removing the oil filler cap and see if it has a ton of blow by. They all have some, but if it's spouting like old faithful then you have need of a new engine. Did you look inside the intake and check to see if the turbo was dusted?
P0284 — PCED Cylinder 8 contribution/balance fault Power cylinder, valve train or injector problem, circuit

 

Ive got my fingers crossed, maybe its just injector o-rings or a bad injector

 

Bad o-rings definitely could make it smoke a bit, and since it only failed the contribution test on the #8 hole....makes me think it could be a single failed injector.