Got 4 oil changes already behind me - all with filter inspections. Some initial Al, but all filters clean after the first oil change over 10K miles ago. Since Al found in oil and coolant circuit (didn't find the coolant debris until Dec as I worked thru the mystery), that's what pointed to the head gasket repair as the root cause.
In the aircraft industry, we do engine oil analysis at a periodic interval - Send an oil sample off to a lab to identify what's in it (brass, Al, steel, etc). Anybody doing this for their MBs?
1995 E320 Sold at 288kmiles