I have a 2004 3500 cummins and live in Iowa.
in the morning when its 20 or colder it takes abought 15 minutes at hyway
speeds so 1900rpms befor the temp comes up to 200 is this slow for diesel?
then when I get to work early and sit in my truck for 5 or 10 minutes befor
going in after 5 or so the temp drops at idle to around 160 -170 and the
enging revs up to 1000 rpms. should the temp drop like this after engine is