Sram BB creaking?

Press fit 86 Sram in BMC. Should I use grease on the cups, the BB is carbon with no alu sleeve? Instructions say dry. I cant make it creak but owner says it does creak badly up hills but he's 18kg heavier than me. Bearings feel fine and they are the ceramic version.
Pegoretti
Colnago
Cervelo
Campagnolo
Colnago
Cervelo
Campagnolo
0
Posts
Colnago
Cervelo
Campagnolo
Can you ride alongside the owner so he can demonstrate the problem and to see if you can pinpoint where the noise is actually coming from? Unfortunately there are lots of potential sources.
Chainring bolts, pedals, cleats, saddle, clamp, seatpost, QR / dropouts, stem, bars, headset etc etc
It might be worth a try.