V50 Engine 2.0D : Intermittant blue-ish smoke

[hoks]

Dear all,

A couple of weeks ago my 2007 v50 2.0d started to smoke light blue smoke for short periods of time out of exhaust when cruising.

I know that blue smoke generally means its buring oil, but since it comes and goes I dont see how could it be something worn out (ex. Turbo seals). Yes it has a bit of oil in air intake pipes, but oil level between oil chages (6000k miles) does not change much, goes a bit down but never had to add it, and oil does not seem to be diluted with diesel.

At this point i have not managed to repeat this problem at will, but it sees like it happens (approx. 2 times per 700 miles) after driving for a while and everything is up to temperature upon coasting in gear from higher speed and then starting to maintain constant lower speed. It has happend at highway speeds and also at city speeds, but right after coasting! The most interesting thing is that it starts and stops like controlled with a switch, and I noticed I can stop it with accelerating fairly hard for 10mph.

Car seems to run ok, no changes in fluid levels, no power loss, cant see change in mpg also...

All filters have been recently changed.
Fitted an EGR blanking plate, so it can not be at fault either...
Bought it with DPF already removed and it did not do this smoking thing for approx. First 1.5 years of ownership.
Had a new throttle body installed, since old one was sticking and cleaning + grinding did not seem to help much.
No lights on the dash...

Could it be something like sticking injector, since I can stop the blue-ish smoke by applying throttle for a bit?

Looking foreward to reading your replys, since I would like to get to bottom of this, but at this point i cant see how a mechanic could sort this out without some random repairs costing a couple of k's and a lot of luck. So if somebody has some experience with this please share.

Sorry for bad english and cheers!