Coolant Overflow

[eoseitz]

I've had a something strange happen to me the past two days. I don't recall it ever happening before. I drove to work and when I park in the parking lot coolant is coming out of my overflow and running out the bottom of the engine bay. The rest of the engine is dry so I am certain it's coming from the overflow.

My belt broke on the water pump about 2 weeks ago and I had to add some water to the radiator. Cold I have too much water in the mixture and it's boiling out? It's strange that it would start two weeks later though. My father suggested the thermostat may be sticking. I always seem to have hot air coming out of the heater and the heater core seems to get the legs real toasty. lol.

Any ideas? otfl

 

[Vettehead Mikey]

Is the stock expansion tank in place and connected correctly? Is the coolant level no higher than max in the expansion tank? What temperature is the engine running at?

 

[LLC5]

I've had a something strange happen to me the past two days. I don't recall it ever happening before. I drove to work and when I park in the parking lot coolant is coming out of my overflow and running out the bottom of the engine bay. The rest of the engine is dry so I am certain it's coming from the overflow.

My belt broke on the water pump about 2 weeks ago and I had to add some water to the radiator. Cold I have too much water in the mixture and it's boiling out? It's strange that it would start two weeks later though. My father suggested the thermostat may be sticking. I always seem to have hot air coming out of the heater and the heater core seems to get the legs real toasty. lol.

Any ideas? otfl

You need to know EXACTLY where the coolant is coming from for any accurate help. Clean the engine bay thoroughly and run the vehicle until you see coolant leaking, then follow it to it's highest point. You could have any number of problems from a blown head gasket to simply having too much coolant in the system. Knowing where the coolant is coming from is key to any diagnosis.

 

[6880 Mike]

Sounds like the hot water shut off valve for the AC has stuck open allowing hot water to flow through the heater core.

 

[eoseitz]

I don't have an expansion tank on my car. I've got a hose rubber hose that comes out of the radiator right by the cap. Should there be an expansion tank on a '74?

I know 100% it is coming out of that hose. I've seen it coming out. There is no space in there to fit an overflow tank. Also, I don't have the AC hooked up in the car any more. I have a hose from the water pump to the radiator. And from the radiator to the heater core and to the engine.

 

[Vettehead Mikey]

I don't have an expansion tank on my car. I've got a hose rubber hose that comes out of the radiator right by the cap. Should there be an expansion tank on a '74?

All '73 and up Corvette had an expansion tank (proper name 'coolant recovery tank' actually), no exceptions. Somebody 'deleted' yours. Coolant expands as it heats up and it has to go somewhere- yours is going on the ground instead of into the recovery tank. It will continue to puke until the coolant level has dropped a few inches in the rad, but then your cooling capacity has been drastically comprised.

The tanks are available at all the usual vendors. Easy enough to install and hook up.