Cissy Houston needs closure about her daughters death .

Cissy and Whitney better days

 Cissy has unfinished business to attend to -- sources say she's planning a pilgrimage BACK to the Beverly Hills hotel room where her daughter died ... all in an attempt to get some closure.

According to sources close to Cissy, she wants to go back to room 434 at the Beverly Hilton hotel and reestablish a spiritual connection with her daughter ... in order to come to terms with her sudden death.

We're told Cissy plans to pray while she's there -- and just spend quiet, contemplative time in the space.

As one source put it -- Cissy "won’t be at peace until she gets closure."