I was going thru 1gal coolant evry 60 miles.1 st checked coolant in oil,oil sample said none.Coolant test said either head gasket or head,or egr,took off egr cooler,was cracked in 3 places,so they determined that was the problem.BAd news,because my motor has had a dozen up grades to the egr,had to go to new style egr,parts alone are 2400 bucks
THe egr,cooler,and head gasket can both show the same symptoms.Extra back pressure into the cooling system,which will cause coolant lossage.Hope all works out
I'm hoping to be back on road MOnday,home for 3 weeks sucks