Hello all. New to the Volvo group. Purchased a used S70 GLT 2.5L non-turbo. Has 149,000 on it. Many maintenance records. Serviced regularly. Has had a new cyl head, etc done at 41,000 under warranty by Volvo dealer. Ederly owner. Been sitting a few months (2-3). Nice car all around. Drove the car home and have been driving the last week or so with no issues. The last couple start ups, i get a puff of bluish/ white smoke. Goes away immediately. Car runs fine. Doesn't drip a bit of oil.
Is this valve stem seals?

 

Possible, I have also seen on an old 850 (same car and motor) the sparkplug holes in the cylinder head had filled up with oil due to a bad oil cap seal. If you can, pull the black valve over off the top of the motor and I will bet you will find oil in there.