Temp After replacing the motor for both fans, the temp. goes to Hot and coolant leaks from the overflow. Could this be an airpocket in the line, needing to replace the radiator or a blown gasket in the engine?

Could be.. is the system FULL? Air in it can cause some odd things. When engine and coolant are COLD (as in after sitting over night), open the radiator cap. Top off the overflow res with a 50/50 antifreeze / water mixture to HOT mark. Start engine, turn heat to hot and fan to high. Top off RADIATOR with same 50/50 mixture slowly & gradually. As the coolant circulates, it should bring any AIR trapped in the system (from heater core & engine block) to the radiator where you can replace it with the 50/50 mix. Once the coolant is HOT and stays level - about an inch under the opening, close the radiator. Monitor the overflow res and add as needed. Good luck!

John sounds like your sensor may be bad. Next it could be your thermostat sticking use a temp gun and measure the temp of your radiator at the cap. Do not remove cap. Just take temp. If it is getting hot it should spit water out. Check to see if the electric fan is coming on the sensor to cut the fan on maybe bad or the fan. Hope this helps.

is the cooling fan coming on when it is hot?

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

check coolant level could be too low allowing air in the cooling system causing air pocket in engine around the engine coolant sensor.coolant sensor needs to be in hot coolant so it will cause the cooling fan to come on at a set temperature.make sure coolant correct level and the coolant level in the cooling overflow jug should be at full cold mark.the cooling overflow jug should never be empty,if you see empty cooling overflow jug air got in the cooling system so make sure when engine cold every time raise hood make sure cooling overflow jug coolant level at full cold mark.if jug stay empty you have cooling leak.so replace radiator cap,if coolant level all good,i would replace the engine coolant temperature and thermostat.when your car come to a long stop or driving along long line of slow moving traffic the engine coolant blower motor should running if not have vechicle code scan for faulty coolant fan motor control module.or ecm problems.

Physically look in the radiator under the cap(if one exsist's) when cool, for coolant level, and check the valve in the cap for sticking. If air is present in the radiator it can't get out, and more coolant can't get in,(from the overflow). Either clean the cap or replace it and check that it is the CORRECT cap.

If radiator is low on coolant fill it to overflowing, replace cap, and check that coolant overflow is filled to the COLD line or mark. The overflow is normally where you would add coolant. (never overfill the overflow)After refilling as outlined above, check the level every morning for 2 or 3 days until coolant level stops dropping below the cold mark and add coolant to the overflow ONLY. Do not open the radiator cap. Also, if you have even a tiny coolant leak anywhere in the system, air will get drawn in, instead of coolant from the overflow.

For more OVERHEATING PROBLEMS try these...
Radiator fins dirty, clean with a strong stream of water, not high pressure water.
Radiator clogged, try backflushing it, or replace.
Thermostat stuck open or shut, replace it.
Water pump worn out, can no longer move enough coolant, replace it.
Fan shroud broken or missing....
Electric Fan(s) not working, Check the fan, relay, fuse and engine temperature sensor's.
Belt driven fan, belt slipping, fan clutch is bad, fan blades have flattened out.
Air dam under front bumper is gone, loose, or broken. It actually has a purpose other than scraping on the driveway or curbs. It forces air up into and thru the condenser and radiator. If it's loose, airflow can actually push it out of place making it useless or blocking the airflow. Along with that, there may also be a plastic piece attached to the bottom of, and wraps up behind the bumper. If it

Hi,
You did well by shutting down quickly.
Why did the water come out when you stopped after the fan belt broke???
Residual engine heat. The engine has fiery explosions going on in the cylinders. Very hot.
Antifreeze flowing through the water jackets of the engine carry this heat away. Fan belt breaks, water pump stops pumping this very hot coolant away, engine temp goes up.
Thus the coolant temp rises enough to boil and push the coolant past the pressurized radiator cap out the overflow onto the ground.
I would recommend a fifty fifty blend of antifreeze and water for coolant. It just cools better.
Not seeing any leaks is very good. Smart thinking on your part saved you money.
Wayne

replace coolant temp, sensor and check for a bad fan relay. check relay first ! to test the fans, run a wire from positive on battery to positive on fan connection. then run a wire from negative battery post to neg, connection on fan. if the motors are ok. the fans will turn on. and make sure you have 12 volts going to fan motors. check relay first!! the fans on a typical engine only work when idling or going slow to prevent it from heating up. have a good day!! make sure there is no coolant leaks anywhere!! this will cause it to overheat also. if need be replace coolant pressure cap on overflow, might not be holding pressure.

Valve cover leak (oil) will not cause this problem, what needs to be checked is your radiator cooling fan, more then likely not working, that's why when your going down the freeway it don't over heat, you have air going through radiator, but when at stop, no air going through radiator to cool coolant before it goes back through engine, starts to get hot, and oil will also thin out, and have low oil pressure, check cooling fan's or fan, for voltage, should have voltage at normal oper. temp. about 210 - 220 deg., if you do have voltage and fan are not on, replace fan motor.

Sounds like the intake gasket or even possibly the head gasket have gone south if everything else has been replaced. Internal engine leaks will cause engine to overheat very easily.

I had trouble with overheating on my 2000 Grand Am, The dealer could not even resolve the issue,(they wanted to replace the intake gaskets)...I knew that was not the issue, no air leaks or water leaking there; so I sit down to think; what are the causes of overheating. Thermostat sticking - nope not it, water circulates, Water leak - nope not it, has water stays until it gets too hot and goes out overflow, fans working - yep...hummmm the only other thing I could think of was losing of water pressure, yep that's it - the cap on the coolant tank was going bad, got a new cap ($8.00) replaced the old one and no more trouble going on 6 months now.

Hope this may solve your issue.