How long can I drive my 2003 pt cruiser with a leaking water pump

I would check the operating temp, could be a bad thermostat, also make sure your heater core is not plugged. In addition make sure you have no air locks in the system.

try replacing coolant tempature sensor

youtube has videos on this subject which are very helpful

Does the vehicle turn off, run rough, or hesitate?

It sounds as though you have a faulty Idle Air Control Valve".

first off your one brave soul to undertake this project. the water pump calls for 9.3 hours. its part off the timing belt operation and should be replaced as well.

does it quit after it warm up or while driving it?your belts might be loose

It is very likely, stop driving it and contact them when they open.

blowed head gasket or cracked or warped head-- that year was bad

1 Inspect Hose Ruptured, Cracked or Leaking Raditor Hose. 2 Inspect Head Gasket Leaking Head Gasket. 3 Inspect Thermostat Thermostat Stuck Closed. 4 Inspect Raditor Cap Worn or Damaged Raditor Cap. 5 Inspect Raditor Raditor Fins Obstructed. 6 Inspect Belt Missing or Broken Water Pump Belt. 7 Inspect Heater Core Heater Core May Be Leaking Antifreeze/Coolant into The Vehicles Floor Area. 8 Inspect Intake Manifold Gasket Leaking, Worn, or Damaged Intake Manifold Gasket. 9 Inspect Cooling Fan Switch - Raditor Faulty Raditor Cooling Fan Sensor/Switch. 9 Inspect Water Pump Leaking Water Pump. 9 Inspect Raditor Fan Motor Faulty Raditor Cooling Fan Motor. 9 Inspect Relay - Raditor Cooling Fan Motor Faulty Cooling Fan Relay. 9 Inspect Fan Blade Broken, Missing, or Faulty Fan Blade(s).