Mechanics

OVERFLOW TANK FLUID BOILING

2002 Mazda 5 • 80,000 miles

Yesterday driving sisters car it overheated and the rad was about ~3/4 gallon short of being full. Added water and it seemed to be OK. Today seemed to be OK while driving but while stopped I saw steam out of the hood -yet engine temp was OK. Rad fluid was boiling in overflow. Let cool down and repeated same; boiling fulid in overflow but engine temp is fine which stumps me. Outside temp is about 75 degrees fahrenheit. Thinking this is a pressure thing rather than temp but this is outside of anything I have seen before. Thoughts?
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Homerbsharp
July 22, 2012.




I would first make shore the cooling system is full and have it presure tested. You might have air in the system. Check the level agen when its cool

Djcl
Jul 22, 2012.
Are the cooling fans coming on? If okay Check and test the thermostat and engine coolant temperature sensor-continues to boil over pressure test the cooling system
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Tiny
Rasmataz
Jul 22, 2012.

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