Thanks for your reply! All dirt was cleaned. I'll check about hours. There was no any water in the sump. I've already cleaned sump and changed oil, will see. Temperature is also within the limit. Could it be piston rings or big end/small end bearings running in?

Hello everybody. I have an issue with my air compressor Sanwa, piston, 3 stage. All bearings and piston rings were changed during DD. Honing also was made. Is it normal that oil is getting little bit dark? When I opened crankcase I found some black substance on the bottom surface, something like pas...