intake manifold

hi; i have a 93 1.0 convertable, on the bottom of the intake manifold there is a female tread for about a5/8 (not sure) size bolt or something . It poped out overheaded and check engine light came on all the antifreeze was gone. not sure what was in there or what it is for. does anybody know if i could just plug it or is ther something else that should go in there,I dont have a clue but someone said it might be there if they were going to put it on a turbo, which this is not, any help would be appreciated thanks joe

joedcio;
Welcome to AF! What part of the bottom of the intake manifold is the port located on (Drivers or passenger half)? I ask as I have a 92 convertible and can go have a look (tonight at home) to see what if anything might be there. Overheating where all the antifreeze is gone does not bode well for the health of your engine. Might have cost yourself a head gasket or warped the head. You won't know for sure until you try to bring it back to life. Hopefully it'll just be an inconvience.

idmetro; thank you for answering,the hole is just about the center of the intake manifold, on the bottom. Its is still on the car, but when I got to take a closer look it is NOT treaded,the person before me apparently tried to make it treaded and was not sucsessfull. What I am pretty sure its for now,is an expandsive plug, its a rubber thing with a bolt and nut through it and when you turn the the nut it tighens the bolt and expands the rubber.You may have known this I didnt,I put it in and so far so good BUT I sure am not confortable with a rubber plug in there, I would of thought they would put something a little more secure. If you have any thoughts on this please let me know thanks joe

Took a look at the intake on my vert and it has what appears to be a freeze plug dead center on the bottom side of the manifold; it's about the size of a quarter. Possibly yours leaked and as you propose someone replaced it with a plug. I's suggest a trip to the local chevy dealer to see what their parts book says. Alternatively you could take a look at a manifold and/or get a replacement manifold from a junkyard. Like you I don't think I'd be particularly comfortable with a rubber plug in a pressurized system.