Originally Posted by adamtheman16

Not sure about the EGR valve, but I think they are talking about the EGR cooler. There are the flanges, inlet and outlet ports, and the seams all welded together using stainless steel. The cooler core may also be welded inside of it. The manufacturer probably uses flux to keep the welds clean and leak-free.

I would see about the next sample if you have no coolant loss of any kind.