Oil smoking When checking oil after running

When I check the oil, smoke or steam is coming out the dip stick tube after the car has got up to temperature. Also the gauge temp is going past half when the car is stopped at an red light etc.

I just got the harmonic balancer replaced as it was making a loud noise. Now it seems to be running a little hotter. The car is 98 oldsmobile Intrigue. It does leak some oil as I have to add oil between oil changes about half a liter.

Could it be the belt is not tight enough? The temp. gauge has always gone up when it is hot out at stop lights. Would like to get this fixed before it becomes more serious.