Upper and lower radiator hoses hard as a rock even after taking out t stat also overheating

Yes, you could have bought a bad T stat. But you might want to check the radiator also.

Blown head gasket letting compression into the cooling system.

1- get bucket and drain radiator down- faucet like thing on drivers lower corner- a couple of gallons 2 remove upper radiator hose at engine block 3 remove elbow - thermostat under it- note how it looks before taking it out! - reverse to install

bleed the system, I use the bleeder screw on the top of the Thermostat housing. Takes 2 seconds, easy to reach. air in the system will not allow very much heat thru the heater core.

Maybe your radiator is clogged.

Sounds like the orifices and passageways in the engine could be plugged up. Try to backflush with a power flusher , if you have one, to force out any sediment which may be in there.

If you can't flush out the engine because you don't have the equipment, try a radiator shop and add the bill on to the ticket, if the customer consents.

If you were to take the upper radiator hose off the engine, and look into the resultant hole, you would see the thermostat.

The thermostat on all cars blocks water leaving the engine and going to the radiator, until the thermostat warms up enough to open.

While the thermostat is closed, water circulates through the heater hose, straight back to the inlet of the water pump. This circulation prevents hot spots, distributing the heat evenly to warm the engine up, and also brings that warmed water to the thermostat.

When the t-stat gets hot enough to open, water leaves the engine instead of circulating through it, and that allows cool(ed) water to flow from the radiator through the bottom hose to replace the water that left through the upper hose and t-stat.

The stub that the upper hose attaches to on the engine should be part of a small housing that is bolted to the engine. Removing that housing is how you remove the t-stat.

The feature than can determine the way the pump turns would be whether they were driven by the smooth side of a serpentine belt on the one had, vs. the grooved side of a serpentine belt or a V belt on the other hand.

It would really be a good idea to get a numeric reading on the engine temperature...

Of course, the number one issue is the thermostat. If it is too high of a range, or is not opening properly, the 4-core radiator will never be called on.

Next is the possibility that steam/vapor is collecting around the t-stat. I had a big problem with that in an Aries K. Once it got hot enough to open the t-stat a few times the temperature settled down.

If the fan is not doing its job sufficiently you will get overheating at stop lights and in crawling traffic, but cooling that is fine above maybe 15 or 20 MPH.

If the bottom radiator hose has failed, it can collapse due to the suction of the water pump. For the whole length of that hose you should not be able to flatten the hose by hand. It should have a spiral of wire, a "spring," inside it that prevents that. If that wire has corroded, and isn't doing its job you can get compromised flow.

When the engine is cold, start it up. Before long, the heater hose that comes out neat the t-stat should start to warm up, while the upper radiator hose stays cold. The closed t-stat forces circulation through the heater system. This causes flow over the hot surfaces, and carries the heat from the area of the cylinders to the area of the t-stat. without that, the water's heat would take 10's of minuted to get to the t-stat.

Next, when the heater hoses get too hot to touch comfortably, but before the engine overheats, the upper radiator hose should start to warm up. The t-stat will start to open, and a little hot water will sneak out of the engine, heating the hose a little. That will introduce a little cold water from the radiator into the water pump, where it will get quickly mixed with the water circulating through the heater system, closing the t-stat pretty quickly. So the initial warming of the upper radiator hose will be pretty slow.

If it overheats before the upper hose gets too hot to touch, you have a t-stat problem. Either the t-stat is failing to do its job, or it is not getting the heat signal it needs to operate properly.

If the heater system is clogged or plumbed wrong, it will not allow the requisite circulation.

I hope this gets you on the road to fixing your overheating problem. A 302 with a mondo radiator as you describe should have no overheating troubles, even in the desert!

First check if you have any leaks in the cooling system , then check if level is correct(radiator and expansion tank , check level when car is cold , never open radiator when it's hot).
Then verify operation of radiator fan , if it's electrical fan it should comes on when temp. goes over normal,
if it's a clutch fan- it should pick up a speed and be more loud. If fan is not on and engine is starting overheating , check upper and lower radiator hoses.
If upper hose hot and lower hose cold or warm then you might have stuck close or prtially closed thermostat , difference between lower and upper hoses when t/stat works ok is about 10-15 degrees,
not really noticeable for hand.So if you don't feel a lot of difference between hoses temp. , and fan is not on , check fan or fan clutch itself.
If lower hose cold , replace thermostat and purge system.
If everything above is working properly , and it's still overheating , you may have bad water pump or head gasket.

remove coolant.remove thermostat remove bottom radiator hose to water pump.put a empty container under the radiator.take a water hose put it where thermostat goes flush out the rust in block.watch the water as it come out the water pump .if stream water is small keep flushing until you get a study sream of clear water. also flush out radiator. lower water pressure dont flush radiator it with high water pressure you could burst it. make clean the over flow jug .make sure it not stopped up.put in a new thermostat and radiator pressure cap. fill radiator with half antifreeze and half water.bleed the coolant system.