Cooling system issue

Got a 2000 tundra 4.7. The heater isn't blowing hot. Put a thermostat in and the lower hose just barley gets warm. Pulled the hoses of the heater core and coolant only trickles out unless you Rev the gas then it runs out when you let off of just barley trickles. Was wondering if the water pump impeller isn't circulating coolant. Any help is appreciated

 

See this reply for troubleshooting steps: https://www.tundras.com/threads/strange-cooling-system-issue.141181/#post-3553351

Did you orient the thermostat with its jiggle valve at 12 o'clock +/- 1 o'clock?

You may have an air bubble somewhere because whoever filled the system didnt properly burp, or because jiggle valve isn't oriented correctly.

Or it may just be the heat control valve in that picture (see link above) and/or the cable to actuate it isn't working correctly.

Truck should have red (or pink) coolant only, to avoid buildup in the system that will cause blockages. Can we assume you're not using yellow or other?

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The new tstat I got from Toyota didn't have the jiggle valve In it like the one I took out.i called and they said it's what it called for. But I pulled the hose off before the heat control valve and still just a trickle unless on the gas some.

 

Did you clock the thermostat correctly when installing? Did you bleed the system correctly?

Any issues with overheating when driving? Does the heater not work?

The bottom hose of the radiator will get warm, it won’t get hot.

 

I would bypass the heat control valve (pictured above) just to see if you get heat. If you do, you know either (A) the valve is bad or (B) the control cable isn't functioning as expected.

 

But shouldn't coola t be flowing out of the heater hose while running not just when on the gas. The main heater hose coming out of the intake is disconnected from the heater valve. When the truck is running coolant just trickles out but when I Rev the gas it flows out like a garden hose. Shouldn't it run out like that all the time not just when being reved up?