Please bear with me here as I explain. S4 1987 N/A stock. The coolant filler neck bolts over the t-stat with two bolts. Under the bottom bolt is a flat ring that looks like it attaches to the wire harness nearby. I changed the t-stat and now I've got a leak at that bottom bolt. If the flat ring's only function is to stabalize (hold in place) the wire harness, then I'm going to remove it and re-torque the bottom bolt. Hopefully, that will eliminate the leak. BUT, if that flat ring is a ground or something else needed by some other system, the thats what I need to know.

 

The flat ring is just connected to the wire harness to hold it in place. I wire-tied the harness and removed the flat ring. No more coolant leak.