Coolant overflow filling up - '77 NYB

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Great_White

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Hi y'all...

So I'm getting ready to part with Great White, circumstances forced a sale, alas. The last couple of times I've had the car out on the highway, I've noticed after stopping that coolant is gurgling into the overflow tank. The temp gauge was just past the middle, and there's no steam escaping. The bottle didn't overflow. I ran the heater and the temp came down.

I'm going to be driving the car to the new owner, a 400 mile jaunt, so I've gotta make sure there's nothing that's gonna strand me. The coolant in the recovery tank looks pretty murky and I don't know when it was changed last. Would a coolant flush and fill make sense, or am I overreacting?
 
Might dip a white rag into the recovery jug and see what the "murk" looks like or possibly came from. Does the insides of the radiator filler neck area look similar? Go from there.

IF you decide to change the coolant, just do a "flush" with water and NOT any chemicals. When the water coming out is clean, let the radiator drain and then refill with about 9qts of green coolant. Many stock the 50-50 mix and now term the old, full-strength stuff we used to get as "concentrate". Use the "concentrate stuff" as the water in the block and heater core will dilute it. 8qts (2 gallons) will fill the radiator, but I could usually sneak another quart in, to put the freeze protection down a bit lower. DO look at the hoses, too.

Put a little bit of coolant into the jug when done, for good measure, too.

The gurgling you heard is normal after the engine stops and convection cooling starts to happen under the hood.

CBODY67
 
Murky coolant is never a good sign, so a flush is certainly in order.

Is the coolant level in the bottle correct? Look for markings on the bottle it will tell you.

The boiling sound you heard means the bottle was doing it's job as intended and that the engine got warm and was boiling out the cap into the bottle.

On my 77 T&C and 78 NYB they normally sit at the second notch from cold. After prolonged highway blasts of 75 MPH plus, they can creep up higher than that, but not past half way.

On shut down I rarely get boiling noises like you describe, but it has happened, and is normal without lingering problems.
 
As stated before, start simple. Purchase a laser digital thermometer for about $15 to point at radiator and confirm temperature. My 440's in both '70 Fury and '78 New Yorker St Regis Coupe show the needle under normal conditions at the second letter "E" of the word TEMPERATURE. What is yours at? At the very least you will need to flush your cooling system and get clean antifreeze in there.
 
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