Coolant Overflow Question

[Terry G.]

After driving my 69 350/350 non-a/c roadster it pushes out coolant from the overflow both while driving and after shutting the engine off. It does not run hot, usually between 180 and 200. I have pressure tested the cooling system and found no leaks. If the coolant gets low, the temp gauge fluctuates wildly. Once I refill the temp gauge returns to normal operation. What could be causing it to push coolant out the overflow and how do I correct it?

Terry Graytgray2@cinci.rr.com

[Terry M.]

Re: Coolant Overflow Question

Have you tested the radiator cap? A poor seal at the radiator cap will do exactly what you describe.

[William V.]

Re: Coolant Overflow Question

If the cap is ok, warm up the engine with the radiator full and cap off. Look for bubbles. Bubbles could be an indicator of a serious problem like a blown head gasket.

BV