1985 delta 88.
Im leaking coolant from under the car. It's dropping from right above the cataylic convertor. What do you guys think needs to be replaced?

 

You sure its coolant and not condensation? I'd lay under there and see where its coming from before replacing anything.

 

Yeah it's coolant... I was driving it and I get back home and hear a hissing sound. Sounded like it was coming from the inside of the dashboard and then I got out and looked under the car and coolant was pouring out :/

 

Pouring out from where? It can run/blow all over the place when your driving. Is the carpet wet on the passenger floor?

 

It's coming from under the car. Like the back of the engine. The floor isn't wet. I thought maybe the heater core or something more serious... the head gasket

 

Check the heater hoses.

 

Could be a soft plug or most anything else. I suggest a strong light get it up in the air and check it out. If it is making a hissing noise you should be able to hunt it down pretty easy. Doesn't sound like a heater core if the passenger floor is dry.... Tedd

 

On a 307 powered car, the most likely cause of a coolant lead from that location is the heater control valve on the rear passenger side of the intake. Yeah, it COULD be a heater hose or even a heater core leak, but the valve is by far the most likely cause. Easy to check.

I've had very bad luck with the aftermarket replacement valves, which typically last one to three months. I even paid dearly for a Delco valve at the dealership (you could still get them ten years ago) and that came in a Delco box that said MADE IN MEXICO. That one leaked too.

I finally threw away the Olds-style valve and instead used the equivalent valve from a Chevy 305-powered B-body. The Chevy valve mounts in the hose instead of in the intake and for some reason lasts a lot longer. It's also much easier to replace when it does go bad.