Cooling fan does not engage

flushing a cooling system is the same method as any other motor

do it without the thermostat fitted
or water pump opening

sacrifice an old radiator hose to adapt a garden hose fitting
for radiator flush

air in system fix
your thermostat housing has no air bleed valve
no top radiator cap

old school way
heater on full
run motor till thermostats fully open
burp radiator hoses
wait till water is running up into over flow bottle without bubble
replace cap
turn off heater
correct level in over flow bottle

why still over heating
you fitted everything i would have ... yet still overheat
possibles
leaking inlet manifold gaskets
hose clamps loose
cooling fans spinning too slow
thermostatic fan switch faulty
aluminum radiator is a big one
air ..fins bent or some water channels blocked

or possible head gasket leak

1. The radiator cap if working correctly it will release pressure in the system provided the cap you have is the correct pressure setting. If you are having a problem with pressure then replace the cap with a new radiator cap with the correct pressure setting. Do not use a cap with a pressure setting other than the original equipment pressure spec. So you do not go to the parts store and buy any radiator cap on the shelf that fits because they come with different pressure ratings and some of these will be totally unsuitable for your car.

2. If the pressure valve is stuck in the "old" cap the pressure release system will not work.

3. Overheating
Air pockets in the cooling system can definitely cause overheating and can retard coolant flow through the system. If you are draining the radiator to replace the coolant or replacing the radiator you need to follow the correct procedures for bleeding air out of the system for that particular engine after coolant refilling. Some engines have bleeder screws on the cooling system to assist in the air bleeding procedure and some don't.

There are various causes for overheating so don't assume it will necessarily be solved by bleeding any remaining air from the cooling system and replacing the radiator cap with one that works.

Other causes can be...........
1. Faulty cooling system thermostat. (Replace the Thermostat)
2. Faulty water pump, especially if the impellers have corroded away or have disintegrated in the case of those design genius water pumps with plastic impellers. (Replace the water pump)

3. Cooling fans not working and if so the cause needs to be tracked. Check that your fans are kicking in. If the engine is overheating the fans should be running because they will switch on when the coolant reaches a specific temp and well before the coolant gets excessively hot.

4. A partial blockage in the coolant passages inside the engine but not in the radiator if you have a new one. If the coolant is not changed at the required intervals(frequently the case with many owners) or is over diluted with water you can get a build up of debris. If products like stop leak have been used in the system this can create similar problems with partial blockages inside the engine coolant passages.

5. A compression leak into the cooling system.
If you have bled air from the system and have continuous air bubbles in the cooling system I would suspect a compression leak. In that event a basic leak down test will show if you have compression gasses leaking into the cooling system and from which cylinder(s). The spark plug is removed and compressed air is forced into the cylinder via the spark plug fitting and air bubbles will show up in the coolant of there is a leak into the cooling system.
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Have the problem with overheating addressed immediately. Running the engine with an overheat condition will cause expensive engine damage many times the cost of fixing the overheating issue.

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you might have air in the cooling system, or water pump might not be functioning right, I would try burping the system first too see. with the car off and cooled down pull the radiator cap off and start the car, let it run for about 30 minutes should force all air out of the system, keep a eye on the coolant level while doing this.

CAR OVERHEATING FIRST CHECK FOR LOW COOLANT IN THE RADIATOR COOLANT OVERFLOW JUG.IF COOLANT LEVEL IN OVERFLOW JUG LOW REFILL ADD COOLANT BACK TO THE FULL COLD MARK.PUT RADAITOR CAP ON COOLANT OVERFLOW JUG START ENGINE LET IT IDLE UNTIL IT OPERATING TEMPERATURE.MAKE SURE TOP RADIATOR HOSE GETTING HOT WHILE ENGINE WARM UP.IF TOP RADIATOR HOSE DONT GET HOT WHILE ENGINE IDLING YOUR THERMOSTAT COULD BE STUCK CLOSE CAUSING CAR TO OVERHEAT.IF TOP HOSE IS GETTING HOT.CHECK FOR COOLANT LEAKS CHECK TOP RADIATOR HOSE AND BOTTOM RADIATOR HOSE FOR LEAKS.CHECK FOR LEAKS AT THE RADIATOR CORES AND PLASTIC SIDE CONTAINERS.IF ALL IS GOOD ENGINE OVERHEATING WHILE IN A LONG TRAFFIC LINE, COOLANT FANS NOT COMING ON.COULD HAVE FAULTY ENGINE COOLANT TEMPERATURE SENSOR OR BLOWN COOLING FAN FUSE OR RELAY.COULD HAVE PCM FAULT.MAKE COOLING FAN ELECTRICAL CONNECTORS AND WIRING NOT DAMAGE OR BROKEN.

ENGINE NOT GOING TO START IF GET TOO HOT FIRST THING I WOULD REPLACE THERMOSTAT AND RADIATOR PRESSURE CAP THEN ADD COOLANT UNTIL COOLANT LEVEL CORRECT THATS WHEN THERMOSTAT OPEN UP AND TOP HOSE HOT.CHECK FOR LEAKING RADIATOR HOSES CHECK TOP RADIATOR HOSE CHECK BOTTOM RADIATOR HOSE.CHECK FOR LEAKS AROUND THE RADIATOR LOOK DOWN BELOW COOLANTS FANS CHECK FOR LEAKS AT RADIATOR CORES OR LEAKS AT THE RADIATOR PLASTIC SIDE CONTAINERS. CHECK FOR LEAKS AT WATER PUMP WEEP HOLE AND CHECK FOR LEAKS AT THE HEATER HOSES AROUND ENGINE BLOCK TO THE HEATER CORE HOSES. THERE IS A REASON CAR OVERHEAT.IF CAR OVERHEAT WHILE DRIVING YOU HAVE FAULTY THERMOSTAT OR LEAKING OUT COOLANT OR BLOWN HEAD GASKET.IF ENGINE OVER HEAT WHILE SITTING DURING A LONG IDLING PERIOD.YOU COULD HAVE FAULTY COOLANT TEMPERATURE SENSOR OR FAULTY COOLING FAN FUSE OR RELAY.HOT WIRE COOLANT TO SEE IF IT RUNS IF NO REPLACE FAN MOTOR. IF YES FAN MOTOR COULD HAVE FAULTY WIRE OR PCM FAILURE. CHECK ENGINE CRANKCASE IF OIL LOOKS LIKE MILK SHAKE ENGINE HEAD GASKET LEAKING.

open the radiator cap and n d let the car run till almost hot this should get rid of any trapped air.

Yes, could have air traped in the system, but from my experience this only gives a false indicator of being hot. When I see a car overheat I think thermosat,fan, radiator cap, or headgasket/craked head in that order. You have already changed the thermostat, so the nest thing to check would be the fan clutch. You can check this by spinning the fan when both hot and cold. When hot it should get very hard to spin- I like less than one revolution when given a good spin.Also a good indicator of a bad fan would be if it gets hotter in town than on the highway. On th e highway you get ram air that helps to cool it down. Radiator caps need the gaskets inspected for crackes and hardness. If crackes are present or to hard they won't seal causing the radiator to overflow. They should also be preasure tested by a local shop or parts store. If the preasure is to low this will also alow the car to heat up quicker and also allow the radiator to empty at a lower temp. The best way to test for a cobustion chamber leak is at a shop. Many shops can test for this right at the radiator with a special dye that will change color in the presence of combustion chamber gases in the collant system. You will notice that I never metioned water pump even though you already change it. Water pumps either pump or they leak, very rarley will they not pump water causing an overheating problem. The only way they will cause an engine to overheat is if they loose the ability to pump water through the loss of the impeller or a broken shaft- or on the very rare occasion an impeller that has run so long that it is worn out.

check fan sensor,fan relay and thermostate.