Suction on dipstick on idle is this normal?

2005 750 when idle I have suction on the dipstick is this normal.

Yes. Crankcase is under vacuum at all times. Engine should have stumbled when you pulled dipstick with engine running. Basically, pulling dipstick creates a huge vacuum leak and result lean condition.

Thanks I am trying to find a oil usage problem. Not wanting to do valve seals. I can't find any leaks

Sometimes oil will leak onto the under panels of the car and make finding a leak a bit difficult. Try removing those covers on the underside of the motor to help give you access to the full bottom of the motor.