My low coolant sensor literally blew off the radiator the other day and caused my car to severely overheat. I have no idea what caused that and for some reason I can't seem to get it to stay in there without leaking now. I was wondering though, has anybody just plugged that hole somehow? I was going to/probably will just try replacing the o ring on the sensor and see if that fixes the leak issue, but i would kinda rather just plug it if there's a good way to go about that.

 

I did before I got my Griffin. Take the old sensor to an auto parts store and have them match it up with a rubber freeze plug (kind with a nut on it so itll expand and seal the hole). Worked great for me. If I would've thought about it I'd have saved my old one before I tossed the radiator a week ago lol. Its a small one, a 9/16, 5/8, something like that.

EDIT: Be careful NOT to crack the plastic end cap when you tighten it.

 

Same thing happened to me a few weeks ago OP.
On mine, the retaining clip was bent a bit and wouldn't hold on to the upper and lower barbs on the radiator at the same time. I pulled the clip, bent it in a bit more so it would clamp tighter, removed the battery (to get access) and made sure the top and bottom of the retaining clip were set properly. No problems since.

 

I think I'm gonna try this. Thanks for the idea!

I think that might actually be similar to the issue with mine.