I thought I would pass this on to the group. I came across an easy to find coupler that allows the oil cooler to be bypassed. This coupler is designed for pressure washer hose and can be found at most home improvement stores. The one in the pictures is from my local Home Depot which had several in stock.
These are handy for testing engines or bypassing a damaged cooler. I wouldn't want to run an OM617 without a cooler for any length of time but not being able to move your car until the cooler can be repaired or replaced is a real drag.