DP started overheating after a repair

What you describe is classic air bubble. There are a number of ways to clear the air bubble. I found the easiest is to use one of the fillers below. Then again, if there's a warranty type thing involved, let them do it. Assuming you used a nationwide facility. If not, and you're going to do it yourself, invest in the item below. You'll be happy you did...Easy to use, attach it in place of your radiator cap and start your engine. Fill the funnel as needed and let the air bleed out of the system...Done....Dennis

Lisle Spill Free Coolant Funnel