I'd be leaning towards an injector nozzle leaking/dripping down, while not running, if you are getting white smoke at start up...and it goes away once running for a bit. I'd be smelling for unburned fuel on start up.

Brian.

 

'06 LR3 175k miles 4.4L Same issue for me, occasional white/blue smoke at startup and spark knock. Took out the injectors and had them serviced at a local specialist. 25 bucks a piece. 2 were totally stuck open the others failed spray tests. 175k miles. Put in new plugs NGK plugs too plus oil change. Seemed to be more responsive and running really good. Mileage got worse and a week later, smoke on startup again. I have changed the pcv and cleaned the EGR valve and intake. Also, cleaned the MAF. Not wanting to fork out $300 for the EGR valve. See what happens. Everything else is tight, runs really good.

 

Follow Up- Still getting intermittent smoke at startup. Doesn't matter if its a cold start or warm after driving. I also cleaned the MAP sensor at the back of the manifold. Total pain to get reach. If pulling the MAP plan on using a mirror. After everything in the fuel/air system checking out I am now leaning toward thinking I have worn valve seals. Will prob pull the valve covers and inspect.