New Liquid Injected Scroll is… Making Noises… Help

New condenser install on an R449A walk in freezer. After running for a couple minutes and shutting it off, it makes this sound for 15 seconds or so… pressures are good, sh and sc are good… has anyone heard this on a scroll before? I was wondering if there was no oil, after adding oil to the system (no sight glass to confirm), it still makes that sound after running. From reading, if the internal check valve is damaged, it can make sounds on shutdown, but I can’t find a description of that anywhere… could this be a bad check valve, and the refrigerant is equalizing? I did a pump down test, and the pressure didn’t equalize, but also, for some reason, the compressor didn’t make that sound after shutting down… submitted by /u/GingerGiraffe96 [link] [comments]