2002 Jetta 1.8T blew 40A cooling fan fuse - overheated, destroyed 4 way cooling hose connector - replaced all- now it still runs very hot, inside temp reads 190 (but temp is much higher), cooling fans run w/ac on lower cooling hose not hot - upper scalding hot- little flow into coolant tank -- thermostat? radiator? (just replaced water pump 7K miles ago)

have a compression test done to check head gasket or cracked head

check high pressure with a proper machine and see how many bar you have ,think compressor may be on the way out .

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.

REPLACE THERMOSTAT AND RADIATOR PRESSURE CAP.CHECK MECHANICAL COOLING FAN.SHOULD HAVE RESISTANCE WHEN TURN WITH HAND.IF FREEWHEELS FAN CLUTCH NEED TO BE REPLACED.CHECK TO MAKE SURE AUXILIARY ELECTRIC COOLING FAN RUNNING HOT WIRE COOLING FAN IF FAN RUNS.YOU HAVE FAULTY THERMO SWITCH LOCATED AT THE BOTTOM OF RADIATOR ON THE LEFT HAND SIDE ON 4 CYLINDER ENGINE FOR V6 ENGINE THERMO SWITCH LOCATED ON THE LOWER RADIATOR HOSE ON THE RIGHT HAND SIDE OF THE ENGINE COMPARTMENT. CHECK FOR BLOWN COOLANT FAN FUSE OR FAULTY RELAY.IF THE AUXILIARY ELECTRIC FAN DONT RUN WHEN HOT WIRED THE ELECTRIC FAN FAULTY.

Are your fans working? If they're not it will cause overheating while stationary or in slow traffic. Overheating while driving points to the radiator.
Get some engine flush into the cooling system and run the car for a couple miles. Then let it cool down and remove all the water(Take both large hoses off the radiator). Then stick a hosepipe into the radiator and let the water run until clear.
If this doesnt work remove the radiator and have it reconditioned/replaced. Removing the thermostat will not cause the engine to overheat. It just causes the engine to take longer to reach operating temp.

Are the cooling fans running when engine overheats?If no find out why.If yes ,is the upper radiator hose HOT when overheating,if not replace thermostat.If fan works,thermostat open and not low on coolant last possibility is a blown cylinder head gasket.

make sure you have radiator full of coolant
run the car to operating temperature
check the operation of the cooling fan
feel the upper radiator hose and the lower radiator hose. they both should be hot.
if one is cold then you may have a bad thermostat or restricted flow
if cooling fan does not come on when engine is hot then you have bad cooling fan switch, relay or motor.
good luck

Assuming engine tune / mechanical condition is not the cause of the overheating:-
Ensure cooling fan is cutting in at the appropriate engine temperature - check operation of the fan controlling relay,
Ensure fan switching control temperature sensor is serviceable,
Ensure cooling system is filled properly, taking care to bleed out air where necessary,
Ensure coolant pressure cap is of correct rating and in serviceable condition,
Check coolant hose on suction side of waterpump is not softened and collapsing at engine revs above idle,
Ensure radiator core is not blocked or cooling airflow inhibited by insects etc.

Check for power and ground to left (large) radiator fan with test light. If power and ground to connector are ok, replace faulty fan.

turn your heater on to max heat and high fan. then see if you can feel the hoses on the firewall for heat they should be hot. make sure that the fan unit on the radiatoris working if the upper radiator hose is hot the fans should be running if they are not that means that either the relay is bad the thermo sensor is bad or the fan unit is shot... please rate the solution..........thanks