I have a 1981 300d and just the other week i had the Radiator flushed and a new temp sensor put in. The question that I have is what is the noraml operational temperature of the car. Mine is like right in the middle of the temp gauge on the dash, is this correct. and another thing I just changed my oil the other day with 15-40w. Well when it seem the engine gets hot I sort of lose oil pressure at idle it goes down to the 2 on the oil pressure gauge on the dash. My question is, is this normal.