What would cause overheating with radiator full of fluid and coolant?

have you checked radiator fluid and transmission fluid ?

Your radiator may be blocked

WATER PUMP PULLY LOOSE, OR THERMOSTAT CLOSED CAUSING BACK PRESSURE.

Really?
There is no magic bullet fix.
Check the following:

1. Coolant level and quality. Replace old coolant with 50/50 blend of ethylene-glycol coolant and FILTERED water;
2. Stuck or obstructed thermostat;
3. Clogged radiator;
4. Fluid loss from leaks;
5. Bad radiator cap;
6. Failed water pump;
7. Failed fan clutch or electric fan circuit;
8. Obstruction to front grille, preventing air from flowing;
9. Worn engine with low output;
10. Extreme operating conditions requiring larger radiator.

Is the thermostat opening at 195 degrees ?
Does the radiator fan come on at 220 degrees ?
Can you tell if the water pump is moving coolant thru the system after the thermostat opens ? Are both radiator hoses hot ?

How long has it been going on? You need to check if you have a bad head gasket. A compression test of the cylinders would tell you. Not saying that's what it is, but that can be a cause of overheating. And it can also be an expensive result of prolonged overheating. That's why mechanics caution against running an overheating engine. If you find the head gasket is good, it will give you great peace of mind, knowing the Shadow's engine warrants a few more dollars in repairs. Compared to the cost of a new head gasket and having the head checked for straightness and for cracks, other repairs for overheating is minimal.
First check the coolant level and keep it full. It could be a worn water pump. Feel for pressure behind the coolant when you squeeze the upper radiator hose for a second or two. The engine needs to be warmed up and running, so the thermostat is open. Try to squeeze the hose closed, then let off and feel for a surge of coolant, and watch the coolant in the radiator for pressure pushing coolant on through the radiator. Kind of a rough test if pump is circulating coolant. You might also try a new thermostat. They are cheap and easy to replace. Clean the outside of the radiator of leaves or dirt. It should be checked for blockage. When upper hose is hot, the lower hose should also be hot or quite warm, just not as hot as the upper hose. If it is, radiator seems not blocked.
Don't worry about having no heat at this time. When the overheating is solved, and coolant level is full, the heater will return.

Hello and welcome to FixYa!

If you have overheating problem, it can lead to multiple issues. You may be running on low coolant that's why the vehicle overheats. If that's the case, please add coolant and make sure that it sits on the right level, too much coolant can cause overheating too for coolant will overflow.

The vehicle may have a faulty or worn out radiator blower motor that's why it overheats. If that's the case then you will need a blower motor replacement to resolve the issue.

If the radiator is clogged with dirt and rusts this issue occurs too. The coolant doesn't flow normally on the cooling system if it's clogged. If that's the case, I strongly suggest that you have the radiator flushed to drain out dirt and rusts. If you think that the radiator served you enough then it's better to have it replaced.

Please do check the radiator hoses, If you have worn out hoses it can cause coolant leakage which can result to overheating. A tiny hole is good enough for the vehicle to overheat.

A faulty thermostat sensor can cause the issue too. If you have worn out thermostat, the fan may not trigger that's why the fan won't work when under stressed conditions. A blown radiator blower fuse can cause this issue too so I suggest that you check the radiator blower fuse and replace it when necessary.

Hope you find this information helpful enough and thank you for using FixYa! Have a good one!

Hello and welcome to FixYa! If you have overheating problem, it can lead to multipleissues. You may be running on low coolant that's why the vehicle overheats. Ifthat's the case, please add coolant and make sure that it sits on the rightlevel, too much coolant can cause overheating too for coolant will overflow. The vehicle may have a faulty or worn out radiator blowermotor that's why it overheats. If that's the case then you will need a blowermotor replacement to resolve the issue. If the radiator is clogged with dirt and rusts this issueoccurs too. The coolant doesn't flow normally on the cooling system if it'sclogged. If that's the case, I strongly suggest that you have the radiatorflushed to drain out dirt and rusts. If you think that the radiator served youenough then it's better to have it replaced. Please do check the radiator hoses, If you have worn outhoses it can cause coolant leakage which can result to overheating. A tiny holeis good enough for the vehicle to overheat. A faulty thermostat sensor can cause the issue too. If youhave worn out thermostat, the fan may not trigger that's why the fan won't workwhen under stressed conditions. A blown radiator blower fuse can cause thisissue too so I suggest that you check the radiator blower fuse and replace itwhen necessary. What causes the radiator blower fan fuse to blow? It's becauseof a failing radiator blower motor, If that's the case have the radiator blowerfan motor replaced. If the fluid in radiator doesn't circulate then it meansthat you have a blown head gasket or a faulty water pump. I suggest that you gofor the water pump replacement first specially if you think that it's near theend of it's service life. Usually, water pops out the radiator when engine isreved (a sign of faulty water pump and possible blown head gasket). Hope you find this information helpful enough and thank youfor using FixYa! Have a good one!

there is no air bleeder, It will bleed it self . Or you could put a pan under radiator to catch coolant spill, Put pan under radiator, remove radiator cap, start engine,let engine run,have a 50% coolant mix on hand, when engine warms up the thermostat will open and allow flow of coolant. just as the thermostat starts to open air will release causing coolant to spill over filler cap inlet, this is normal, the pan is so you don't waste coolant or make a mess. in a few moments as the thermostat opens to full position the coolant level will fall in radiator, at this time you will fill radiator untill it will take no more,put cap on radiator and use clean fluid you caught in pan or coolant in jug or whatever you have it in and fill the coolant reservoir to fill line. i hope you have heat now ! check reservoir again the next day, if low fill and you should be good !! do this procedure when engine is cold,never remove a hot radiator cap. but if you were too, make sure you squeeze upper radiator hose, IF IT IS HARD OR UNDER PRESSURE, DO NOT REMOVE !!!! If you can squeeze the hose then put a rag over cap and remove slowly a little pressure or coolant might spill but should be minimal. I have alot of experience in this and severe burns are possible to the inexperienced !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Replace the bad radiator hose first.  Second- get you special formulated anti-freeze dye from the auto store and pour it into the radiator.  Third- make sure you got all the air pockets out of your system, cause the coolant system won't work with air pockets in it.  Fourth- Check for leaks by looking for the colored dye.  If it's not the radiator hose, then could possibly be a pin hole in your radiator.  Would suggest replacing all the radiator hoses at the same time while you got the coolant system disconnected, cause you don't want to have to come back and replace another hose in a few months.