Clogged Heater Core or Bad Water Pump

[Flash Gordon]

My cars temp gauge spiked out a couple of weeks ago sitting in a drive thru line.

A week or so prior to this I topped the coolant off with the green stuff. I believe what I had in there was the red stuff? After reading around a bit I hear different opinions. Many have claimed if you mix the 2 it will cause them to gel up in your radiator and/or heater core

I pull the radiator to check and see if that might the problem, but water seems to be flowing fine through it
My next step is to pull the thermostat then try and run water through the engine while it's running (and to also to see if the water comes out of the bottom radiator hose)
The engine accepts about 1-2 quarts of water before burping it back out the thermostat hole.
Water doesn't flow through the bottom radiator hose until the engine is turned off. Once the engine is off the water flows into the drain pan



Any thoughts on this will be greatly appreciated



fwiw I was able to salvage at least 3/4 of the gallon of the green coolant. The majority never left the recovery tank

Thanks again

[Ange]

try flushing the system with a gardenhose at high pressure

[Flash Gordon]

try flushing the system with a gardenhose at high pressure

Would it be best to do this with the radiator installed?

[toddrs93]

Mixing the coolant will not cause any problems. Are you sure the fans are coming on when they are supposed to?
If you just feel both heater core lines where they go into the firewall after the car has heated up, they should feel the same temperature. If the heater core is blocked, one line will be much cooler than the other one.

[Flash Gordon]

Mixing the coolant will not cause any problems. Are you sure the fans are coming on when they are supposed to?
If you just feel both heater core lines where they go into the firewall after the car has heated up, they should feel the same temperature. If the heater core is blocked, one line will be much cooler than the other one.

Would a bad heater core cause water not to circulate through the engine ?

[Flash Gordon]

radiator cap fwiw

[DocWalt]

radiator cap fwiw

I appreciate you coming back and updating on what the issue was. It's a right PITA when you find a thread with the exact problem you have and the OP never updates on a fix.