Yes
Engine coolant expands when heated. Heated coolant needs a reservoir to come and go as needed.
2
No.No.
Coolant reservoir, or directly in the radiator. If you are having to add much coolant, you need to find out why. Serious engine damage can occur if it is leaking inside the engine.
100,000 miles.
You need to get one. Cars need it in the case if it's too much of the coolant. Without the reservoir the coolant in the case when there is some extra will go on the ground. Which is in some states is a crime because it's hazardous and not nature friendly.
Front disc, rear drum.
The low coolant sending unit is integral to the coolant reservoir. I just called two dealers, they were both $117 for the reservoir(!!). Before replacing, try cleaning the contacts on the connector, and also try cleaning the sensor in the reservoir with a long bursh before spending that much money.
The plastic coolant reservoir on the fender feeds directly into the coolant system. Just add coolant to the reservoir and if you have drained the coolant or otherwise emptied the system, you may need to check the level in the reservoir after running the engine, or more accurately, after the engine has cooled. Once the coolant level has stabilized, just check it periodically to make certain that the coolant level never gets too low.
If it has a manual trans, then yes.
Dexcool, I just had to add coolant (reservoir was bone dry!) to a 2007 Aura
In order to change the timing belt in your PT Cruiser you will need the new tensioner and timing belt covers. Your dealership should have the parts you need