If you work on your Saturn Ion's thermometer or its coolant temperature sensor, you need to deal with the coolant recovery tank. In the Saturn Ion, the coolant recovery tank is called the coolant surge tank, and if you find yourself in need of replacing yours, it is a fairly simple task. Here is how to replace your Ion coolant surge tank safely and quickly.
Turn off the engine and leave it off for at least an hour before starting the job. This gives the engine a chance to cool and the expanded coolant to flow back into the radiator. Disconnect the negative battery cable to ensure safety.
Get a drip pan and loosen the drain plug on the radiator. Drain just enough coolant out of the system to empty the coolant surge tank. Re-tighten drain plug. Remove the bolts holding the coolant surge tank in place and disconnect the line that hooks the tank and the radiator.
Wipe any coolant spills with a shop rag. Dispose of the used coolant in a tightly sealed container away from children and pets because it is very toxic.
Install the new surge tank by first installing the line, then the bolts. Tighten the bolts, but take care to not crack the new tank.
Open the surge tank cap and pour in a 50/50 mix of Dex-cool and water. Be sure to fill to the cold fill line. Re-cap the coolant surge tank pressure cap and reconnect the negative battery cable.
Start the engine and check for leaks.
