There's coolant in that there hole?

[GTOger]

As you may have read elsewhere on this forum, we just took the ZR-1 on a nice little trip and put about 3k miles on her. The car performed flawlessly the entire way.

Then the weekend we get back, the car starts running rough. Stumbles at idle. Backfires when you lift off the gas. Shakes. Rattles from the top end. It's not itself. Every time I've had opportunity to be under the hood it's been dark. Tonight I got out some lights and had a look.

One of the first things I notice is a wet spot on the underneath of the hood. It's roughly over the back passenger side spark plug. Uh oh.



Then I look around and find:


And this:


And this:
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A very careful eye will detect areas of green coolant around the bolts and in the valley and it looks to me like it has come from somewhere in the vicinity of that back passenger side plug.

Tomorrow afternoon I will pull it and see what I can find, although as we all know the visibility into that plug hole just plain stinks.

Avid readers may recall the wife and I pulled the plenum and did an injector replacement on this motor just before Christmas time. We've put somewhere around 3500 miles on the car since then. It sure is gonna stink if we have to pull this thing apart again.

Advice and suggestions, as always, are welcome and encouraged.