After the issue reared its ugly head I have been doing all the work myself, that is the only way I can know exactly what is done and what is used.
The filter that is in it now was purchased from gm dealer and is supposed to be oem. next time I change it I will insure that the one I use has a check valve.
I can assure you that it has the proper amount of oil in it.
When i used the mmo it of course thinned out the oil and seemed to make the noise louder and still after a minute or two goes away completely.
Keep in mind that I am now doing everything myself t make sure it is done right.