This is my first post. I recently joined because I bought a 89 RS 305, auto, T-Top one owner Camaro from a girl I work with. It had been setting for a couple of years. I drove it home (about 15 miles) and noticed it looked like it had straight water in the radiator. I'm in the south so it hardly ever gets below 15 degrees. Anyway I drained the water and put a gallon of antifreeze in it. While the car was running I tried to fill it but it wants to blow antifreeze back out the filler hole. So I cut the car off, filled up the radiator, and filled the overflow up to the cool mark. Now when you crank it you can look in the overflow jug its blowing bubbles and making the antifreeze look like green foam. Anyone know what this is. I have messed with a lot of cars in my life but I have never seen this. The car never overheated on the way home and is not blowing steam out the exhaust. It also has no water in the oil.

Thanks

Sounds like a head gasket. It's most likely blown between a water jacket and a cylinder so thats why the water and oil aren't mixing. It's the combustion pressure thats blowing the bubbles and forcing the water out of the radiator. Do a compression check to be sure.

could just be air pockets coming out of the block from sitting up so long.

or a bad/loose radiator cap.

Thanks everyone for the replys. I went and bought a new cap this morning. Between that and air caught in the system I believe I fixed the problem. When I drained the water out of the radiator yesterday I just unhooked the lower hose. I just topped it off and let it run for 30 minutes and I see nothing like the bubbles I seen yesterday. Maybe just a couple. I believe it may have been just some air pockets. I believe the cooling system needs a good flushing. Thanks again.

Yeah, this usually results from a head gasket or busted cap. Glad it seems fixed. Now start checking relays and sensors and replacing them all. We dont want to hear Im overheating now or my temp gauge isnt reading. You sound like you know a little so im sure thats what your doing next anyway.

Take care, and hope to see more posts from you.