Overheating all of a sudden

[jerrybramlett]

If the car was running hot on the way home I did not notice. I had it parked in the driveway idling, as I was resetting the idle. As I walked away the car boiled over.

I'm just curious. What was your temperature gauge reading during this boilover?

Some mechanics make the mistake of bringing the coolant level all the way to the top of the fill tank. The tank should be left half full. When the level is too high, the car will puke out the excess coolant during the next few warm-ups.

Remember that while checking your timing, the distributor vacuum canister should be temporarily disconnected.

 

[dlrshort]

Thanks for all your help, everyone. As it turns out, it was extremely low on coolant. One of the things that was repaired by the mechanic was the hose between the expansion tank and he radiator was replaced. It had been oozing coolant for some time now. The mechanic must not have checked the system. It is fine now.

Rule #1: Check the obvious..................

 

[dlrshort]

What ratio of coolant to water do you all use for the cooling system? How does the addition of water affect the cooling and heating potential?

 

[JohnZ]

The system is designed to operate with a 50-50 mix of glycol-based coolant and (distilled) water; that protects against freezing to -25*F, and provides boil-over protection to 265*F with a 15# cap. Increasing the coolant concentration above 50-50 will reduce heat rejection efficiency somewhat, as water has a higher heat transfer coefficient than glycol. Just leave it at 50-50, and drain/flush/replace it every two or three years to maintain the effectiveness of the anti-corrosion additive package (aluminum radiators are expensive).

RETARDED timing (not advanced timing) causes hot idle temps - properly advanced timing (with a properly-calibrated and manifold vacuum-connected vacuum advance unit) will reduce idle and traffic temperatures significantly. If your base timing (set with the vacuum advance disconnected) is 10 degrees, connecting the vacuum advance should bring it up to 25 degrees or so, where it belongs at idle.

 

[WayneC]

"Coolant to water"? Do you mean antifreeze to water? Read the antifreeze container and it'll give you the ratios for protection to prevent freezing to various low temperatures. 50/50 is probably fine, unless your area experiences extremely low temperatures and the car stays outdoors.
I doubt thaere's much heating or cooling difference.