On the water pump the impeller can fail. This will impact the flow of coolant and can lead to overheating. As the pulley will spin the water pump but it will not move any coolant on the inside.
If it gotten worse after the thermostat, could it be possible that you have gotten a defective thermostat?
Typically, with a stuck closed thermostat, you will have temperature difference between the upper and lower hose. One will be hot and other will be noticeably cooler. This indicates the coolant is not flowing properly.
Nov 19, 2021 at 1:48 AM