I have done three heater cores at my dealership on 06 H3's and theres no mistaking it when it's bad. You blow mistout the vents and it stinks of coolant in the cab. I pressure checked the last one to see what was going on and it was a seem leak the side tank. It is a pain in the *** and I feel bad when I have to give one to a tech. because it is a loser of a job. You have to remove the whole dash carrier to replace the core in one of these trucks and when working on trim you have to go slow and easy not to mark up everything going out and in. Steve

 

Just as long as you didn't blow a seal we won't think anything less of you.