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Q: No coolant in fill bottle

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I just drove my daughters Holden Astra (in australia) and I noticed the temperate gauge go a little over half. I drove about 4 minutes to get home and it stayed on a little over half but when I checked water flll bottle at home it was empty. There is not radiator cap only fills up from fill bottle. Could I have done any damage to the motor if there was no water in system at all? I am waiting on it to cool down then will put coolant in.


Also my daughter said that gauge normally sits on half. Car has only been driven twice in last 5 weeks.

My car has an automatic transmission.

Hello, thank you for writing in. You are right in that your vehicle’s cooling system is a "closed system". The overflow tank you are referring to is known on this system as being more of an "expansion tank" for when the coolant heats up and needs a place to expand. To check the coolant level, you will want to poor in water (or coolant/antifreeze if in an area that will freeze) up until it hits the "cold" mark on the expansion tank. If filling it when the car is warm, you will want to fill it up until the "hot" mark. The engine can become damaged if it over heats. Without coolant in the system, the thermostat will likely not give you accurate readings on your dash board. With that being said, you will want to fill it up and observe how empty it was. If you add a gallon or more, there is some kind of leak (internal or external) in the system. At that point, more diagnostics needs to be done. For more help with any further testing, contact our service department to schedule an appointment.

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