checked oil and it looks thick like sludge this morning ? on 2004 Volkswagen Passat

and yesterday while driving oil pressure light came on for a few seconds ?

Asked by for the 2004 Volkswagen Passat
It is critical on those engines that the oil be changed frequently, seen a lot of those engines fail. Get the oil up to operating temperature and change the oil and filter. I would use a WIX or genuine VW oil filter and synthetic oil.