Originally Posted by Scrumgees
thanks for the reply but im still unclear one one thing. why once the engine warms up and the thermostat competely opens, and i have verifed this pulling off the thermostat neck while the engine is good and hot too, is there still absloutly no flow through the radiator? at some point it should begin to flow right? This problem is present from idle all the way to the top.
I forgot so i should also say, following a hunch, i figured maybe it could be pressure related problem holding the thermostat closed so i tried flipping the thermostat up side down and it actually got the temp down to 210 from 250 degrees. My gut says its just spinning that impeller in an air pocket though.
If you pulled the gooseneck loose there should be coolant all over the place. The coolant level in the radiator should be higher than that of the engine and the upper hose should be full though not circulating.
The first thing is to fill the system completely with no bubbles. This takes running the engine while filling till the thermostat opens. This allows the system to complete purging trapped air. When the engine cools the coolant level will go down because the coolant contracts as it gets colder. Refill when it's cooled off till the system is full again. The system needs an overflow tank. When the system is full cold; as the engine heats the coolant it will expand and needs a place to go where the system can recover that excess quantity when it cools again. This keeps the system operating full under a large range of operating conditions and it prevents the system from sucking in air as it cools off. Air mixed with hot coolant is extremely corrosive to engine parts (especially aluminum). Air MUST be kept out of the cooling system to the greatest extent possible.
The pump, not being there I've been taking something of a shotgun approach so far. The pump could be missing or have a loose impeller. Even a simple spinning disk with no vanes at all will inside a pump cavity result in a flow of liquid, not a good flow but a flow none-the-less. Even a reverse rotation pump will pump something when turned backwards again not enough, but something to see. No flow would indicate that either the coolant level isn't high enough to prime the pump, or there is no pumping action from a missing or loose impeller. The back comes off the pump, so this is easy to check.