Guys, how does once know if the engine's water pump is still working? Previous posts said to check if there is water movement sa radiator upon opening the radiator tank cover. Kasi kanina I replaced my thermostat with a new original one as well as my radiator tank cover and I noticed after filling up my radiator with water, the water doesn't seem to be circulating? Parang walang flow. Of course there wouldn't be flow if the thermostat was still closed so I made sure to warm up the engine muna. The thermostat opening was signaled by sudden bubbles coming out of the radiator opening then the water level went down a bit. This meant that the thermostat opened upon hitting the recommended temperature (Thermostat opens at 85C according sa box) thus allowing water entry into the engine block. However as soon as the water level settled na, I couldn't see any water circulation or movement. Hmmm...I've never overheated naman before. As far as I can remember, I haven't changed my water pump yet since we got the in 2000. You think its time to replace it already as a preventive measure? Thanks in advance...