As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OIL SMOKE ENTERING THE CABIN AT FLOOR LEVEL. TROUBLESHOT THE CAUSE OF PROBLEM TO A FAILED LEFT AIR CYCLE MACHINE, THE PART WAS REPLACED WITH AN OVERHAULED ASSEMBLY. ALSO THEY FOUND FOD IN THE RIGHT HEAT EXCHANGER WITH SIGNS OF OVERHEATING, IT WAS REPLACED WITH AN OVERHAULED ASSEMBLY. OPERATIONAL CHECKS WERE PERFORMED WITH NO FURTHER DISCREPANCY AND AIRCRAFT WAS RETURNED TO SERVICE. OPERATOR DESIGNATOR W6JA, CONTROL NUMBER W6JA20210705046.