Overheating Polo VW Polo Classic 1.6 2001 model sedan. Car overheating. Fan comes on but only when very hot. Have flushed and refilled radiator, etc but still overheating quickly although fan does come on. Is this the thermostat and where do I replace?

Belts only drive the water pump and other accessories and do not cause overheating. Have a pressure test done on the cooling system. Have a compression test done to check for head gasket or cracked head. Have a flow test done to check for blocked cores in radiator .check external fins of radiator to see if they are flaking off. Flushing radiators doesn't work because once the cores are blocked up there is no way to un block them. If you have a viscous fan hub have it check out as they stop driving after a period of time.

Visit the on-line store, known as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem.
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Did he flush the radiator? If not kindly ask him to flush the radiator and then refill it again.

THE SENSOR FOR THE TEMP OF WATER , A BAD IMPELLER ON THE WATERPUMP (PLASTIC AND CRACKS), THEN THE FAN IT SELF

WHEN CAR STARTING OVERHEATING MAKE SURE COOLANT LEVEL DIDNT GET TOO LOW. IF NOT I WOULD REPLACE THERMOSTAT AND RADIATOR PRESSURE CAP IF OVERHEATING WHILE SITTING IDLING COOLING FAN NOT COMING ON.CHECK COOLING FAN FUSE AND RELAY IF ALL IS GOOD.CHECK COOLING BY HOTWIRING IT.IF RUNS YOU HAVE A BAD COOLANT TEMPERATURE SENSOR OR FAULT IN WIRE CIRCUIT.IF FAN DONT RUN WHEN HOTWIRED REPLACE FAN MOTOR.IF CAR STILL KEEP OVERHEATING CHECK ENGINE OIL LOOKS LIKE MILK BLOWN HEAD GASKET.IF OIL LOOKS OKAY YOU NEED RADIATOR AND ENGINE FLUSHED OUT.

Check that your electric radiator fan is working. When the car is hot and idling it should come on.

Replace your therostat. I had a Chevy Citation that the thermostat would start to open and then close instead of opening all the way.

hi is the water flowing through the engine ie radiator blocked, water pump. regards

sounds like the plastic impeller has broke on the water pump.

Check radiator for coolant (directly, not just from refill reservoir).

Remove thermostat temporarily for troubleshooting.

Check radiator fan operation.

Check for water in oil=blown head.

did the electric fan on the radiator start up? if this dont start up, it can get the engine overheated , specily if the car run in hot weather , an when the car stay on idle . The other problem is the engine head , the head gasket can blow and you get the compresion presure in the water chanal .Try to se of the oil on engine is gray? If gray you must change head gasket.
Hoope this can help you