Attention: TDR Forum Junkies My 2001 3500 DRW 6 speed temp is up & down a lot more than it has been in the past. It used to get up to about a needles width above 190 & then drop back a little & stay between 180 & 190. Now in the last couple of weeks it gets up to around 210-220 then drops back to about 170 then creeps back up to about 190 , of course it was in the low teens when this happened , but it did get my attention. Do I need to change t-stat & change coolant. If so does anyone have the Cummins part# & what type of coolant do I need to use. Also is draining enough or does it need to be flushed. Last one, I have 2 cracks on top of my dash on the passengers side ,one is about4"-6" from the a-pillar , the other is about 12" over from that anyone else seen this? TIA 
