Low Coolant

[phewop118]

I've been getting an intermittent low coolant light for the past 6 months or so. It used to come on only when I started the car after it had been sitting for about an hour. However, Recently, it's been coming on every time I start the car and lasting until the car reaches full temp. It will also come on if I idle for a few minutes, such as in the drive thru. At those times, there is also no heat, so I assume the heater core is not receiving a good flow of coolant. When I begin to drive away, the heat comes back and the light goes off. All this time, the temperature as shown on the instrument panel is within operating range, never even exceeding the half-way mark.

Today I popped the hood to actually look at the coolant level when cold, and it certainly was below the full line in the surge tank. I opened the tank and added several cups (at least 30oz) of coolant and water, but the coolant level doesn't appear to have risen much in the surge tank. When I turned the car on, the coolant light was still on. Tomorrow when it's bright out I will look at the coolant level again and see if I can figure out how low it actually is. Should I get my system pressure tested to see where there may be a leak? I do know my water pump has been on the blink for quite some time, so I'd assume that's where its leaking out. But I realize my engine compartment is very dusty and dirty, so I'm wondering if there may be a hose somewhere that has a slow leak. Finally, does anyone have any explanations as to why the light might be so intermittent like that? Esp. when it lights up when idling and the heat dies.

[carbon02]

This car has a float inside the plastic coolant tank that monitors the level and turns on the light. The light goes out when it's warm because the coolant expands enough for the float to rise enough to shut off the switch.

You may have a leak, or you might have an air pocket in the system. There's a air bleed screw that is black plastic at the top of the radiator tank. The tank on the passanger side. Open this screw while cold and you can bleed air out of the coolant system.

You may need a pressure test to determine where your coolant is leaking. You can rent the tool from AutoZone and test it yourself if you want to try to find the leak.

With lack of heat, you either have a lot of air in the system or there's problems with the coolant circulating.