Blue smoke on extended idle. 2006 4.8is.

[masurati]

I have a 07 4.8 x5 with 71k. Mine is doing exactly same. After idling for 5 minutes
It blows out white smoke once i rev it up and then It takes another 5 minutes and
Another rev for the smoke to show up. Smoke smells like a burnt tire.
I would be 100% sure i had leaking v seals if it was not for this one strange thing:
If i idle it with oil dipstick removed then it does not smoke anymore.
I changed ccv pipe and ccv valve membrane and it did not help.
Since it does not smoke with the dipstick removed i think its a ccv
Related issue and not leaking valve seals. What other ccv components
Can i change? Any ideas?
Thanks.