Q: Coolant is not being pulled from the reservoir.

Hello. From what you describe, it appears that your vehicle may be leaking coolant or may perhaps have air in the cooling system. First off, I would carefully inspect the engine bay and undersides of the vehicle for any signs of coolant leaks. Any wet areas, drips, or puddles could help you determine where the coolant may be leaking from.

If there are no leaks, then it may be possible that there are air bubbles trapped in the cooling system, which could be what you are hearing. If you recently replaced the thermostat, I would carefully check the thermostat housing as well as any hoses that were removed to see if they may be the source of the issue and go from there. I would also be careful in driving the vehicle as leaks or air in the system can cause engine overheating, which can lead to engine damage if not attended to.

I recommend having a certified technician, such as one from YourMechanic, come to your location to inspect the coolant system for a leak and suggest necessary repairs.