1991 Ford Ranger - Thumps

thumping noise and up and down temperature gauge

sounds like 2 problems, but impossible to tell since you didn’t tell us hardly anything. Ad a LOT more info and we’ll try and help.

Yes, please tell us more. I wonder if the thumping noise is air in your cooling system. Is the radiator full?

I installed top and bottom radiator hoses , new thermostat , flushed system @ home and new ect sensor . No luck .Took it to a shop , maybe they could find problem with proper tools . Recommended motorcraft thermostat and sender . Still have the issue ???. Suggested a revised water pump for this 4.0 ol engine in my ranger . But offered no warranty ???