I was going to suggest get some engine flush, then change the oil and filter to atleast good brands, ie: Motul then start it and see how it goes, then move on to the next, if your really worried you could do comp and leakdown tests to see any underlying issues after oil change.
Curious what happened prior the last two weeks or has it been long term issue. As well as when was the last service done KM'S as well as what oil's were used last time.
Cheers