I have looked till I'm blue in the face everyone talks about water pump cavitation but is it something that you can see with the pump off ?
I'm so sick of this car overheating motor and pump are about 3years old Mazda reman ,i had the radiator recored last week the blocked flushed new 160deg thermostat please help

 

waterpump cavitation is when the waterpump spins so fast that it creates air bubbles around the impeller and stops pushing water thru the block... you can't see it because it happens when the motor is at RMP...

You probably have an air bubble trapped in the system... start your car with the radiator cap off and let it get to operating temp... once warm the therostat will open and the coolant will flow and allow the air to bleed out(you can assist by squeezing the upper hose) fill to the top with coolant and place cap on the system... make sure your overflow is about half full or so

 

You can have damage to the impeller due to repeated, extended cavitation. The bubbles created are extremely abrasive to the blades and will erode the impeller. You can visually verify this by removing the pump and examining the impeller blades.

Other things to check:
Two belts on the water pump?oem=air pump belt and alternator belt. Air pump removed must add double alternator pulley and yoohoo belt.
Belly pan in place?
Radiator OEM ducting in place.(from the bumper opening to the top of the radiator)?
OEM fan clutch working properly?
Electric fan adequate, proper temp controller?(if efan is used)
Is the coolant pushing out into the overflow tank? The cooling system must stay full or a bubble will get to the pump impeller and give you erratic cooling. https://www.rx7club.com/showpost.php...1&postcount=11

Good Luck!

 

Dbl post!