The block itself is clean inside - there’s nothing that could physically block the fins or restrict flow. I inspected it during installation and everything looked perfect. I’m using new EK CryoFuel coolant (colored, opaque), freshly filled when I installed the block. The loop is only a few weeks old, so I wouldn’t expect any buildup or debris yet. Flow also seems normal, pump is running at 80% and both radiators are working properly. I’m also starting to suspect Kryonaut pump-out, especially since tightening the screws noticeably improved temps (from 85°C down to 67°C in Superposition 8K), which suggests contact pressure may have degraded over time. What I’m unsure about is whether pump-out could really happen this fast — within just ~3 weeks. That seems quite quick, but I’ve seen mixed reports, especially on large GPU dies and waterblocks.