Nissan Repair: 1995 Nissan Van-smoking, blue smoke, probaby

Question
I was driving my van the other day and I had to stop to pick up a bag of mulch that fell out the back. When I put it back into drive from park, there was a hell of a squeal and then a bang and dark blue smoke rolled out the back, and it smelled like something was burning. I drove very slowly on and another half a mile there was no more smoke, no smell of burning and the van was running as usual. I have driven it a short distance since one day and there was no problem with it. What could have happened that day? What could have caused that and yet it still runs, no ticking, nothing?

Answer
Bonnie,

The problem is probaby the PCV sticking when the vehicle was stopped.  This probably means that the oil is sludging up in the engine and should be changed a couple of times to get things freed up.  The drain back holes are probably plugging up and that is where the PCV got hold of that much oil at once.  Blue smoke usually indicates oil burning.