No, not asking about creaking :) On my gravel bike with Campagnolo Ekar (press-fit BB) after removing the chain from the chainring, when spinning the cranks they spin only for a few seconds (I heard that means the bearings are correctly greased) and I hear a faint, steady "rattling" noise. It sounds almost like an internal gear hub when running or a dry chain. Here is a short video demonstrating the noise (disregard the husband whistling in the backround). The video exaggerates the noise somewhat, it's almost impossible to hear with the chain installed, as it is drowned out be the regular drivetrain noise. However, in comparison, the square-taper BB on my other bike is completely silent without the chain.
Is this normal? Should I take it apart to see what's going on? This was immediately after a ride in the cold (around 0 °C), could it be possible that the BB shell contracts due to the temperature and compresses the bearings?
The bike was bought last summer, and I rode it for about 1000km in all weather (with mudguards in winter), including snow & road-salt, rain, and on various dirt tracks. I never used a pressure washer or garden hose to clean it, only a shower with low pressure. I didn't do any crazy jumps, only a few high-speed downhill bunnyhops over potholes.
I removed the crankset. The bearings don't spin freely at all, particularly the drive-side one requires some force to turn. Turning the bearings I feel some distinct "latching", like turning a rotary encoder button on some electronic gadget, or like turning the axle of a dynamo hub (but much weaker). The "latch points" occur in regular intervals (a few degrees), so I don't think dirt is the cause. In contrast, e.g. the axles of the wheels turn completely smoothly inside the hub (but don't spin freely either). I don't think this is normal for the bearings? Can pitting be the problem?
To my untrained eyes, the bearings look OK:
The BB cups are clean as well:
I contacted the manufacturer. They suspect the BB cups were not pressed-in correctly and are out of alignment, which in turn damaged the bearings. I will have the BB cups pressed in again to re-align them, and the manufacturer will have Campagnolo replace the bearings. If the problem re-appears after the next 1000km, the frame might get warrantied. However, they also confirmed that Ekar cranks always only spin for a few seconds because of the seal, so that part is normal.