I changed my oil this past weekend and made a switch from M1 0W-40 to Pentosynth 5W-40. I also used a Mahle oil filter instead of the Mann filter from the dealer. The last 2 monring have been pretty cold in SE Michigan, approximately 2 degrees F yesterday and 12 degrees F today. When I start the car in the morning after it has been sitting all night I get about 1-2 seconds of a grinding, metalic sound. After that everything seems to be fine. This has been a fairly cold winter with several below 0 F days and I have never experienced any noise at startup. I have been using M1 every 5k miles and this was my 35k mile service. Any ideas on what could be causing this noise? New oil, different filter, gremlins?