We had our first mid 20's temp night last night. I went out this morning to start my car and there was some grey smoke on initial startup and a tapping sound. When I opened hood and tracked it down I could feel a rythmic tapping on the oil filter. Unlikely it is coming from there but does anyone have any ideas what in the world is going on here? Don't want to start it up again without some idea what is happening.

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89 190E
2.6L
Arctic white
Grey leather
Sunroof
Pirelli P400 rubber
Smoked corners