Check the lower hose. Been having the same issue
There are 19 pages of personal experiences in this post.
I went with CSF. Paid around $120 + Shipping at RockAuto.com
The box arrived wet and mostly destroyed, but the radiator inside was intact.
So far it's been about 3 months since I installed it and is working great. I got my temps back to normal.
I do have a small leak that I can't find. I need to add about 1 inch of coolant to the reservoir every month.