Either the radiator is blocked, or the thermostat is stuck closed, or the water pump has failed.or it just needs water.
a bad termastat
There are several possible causes. 1. Check the fan. When the car is overheating, if the fan is spinning slow that means the clutch is defective. 2. When overheating, touch the upper and lower radiator hose. If upper is cool, replace the thermostat. 3. when overheating, upper hose is hot but lower isn't. That means the radiator is clogged. 4. upper and lower hose are both cool, water pump is defective.
check the fins on your radiator they could be corroded and loose decreasing your radiator s ability to cool the engine or the thermostat could be defective also
Open the radiator cap when the engine is cool, check the radiator's fluid level, and add appropriately. NEVER OPEN A RADIATOR CAP WHEN THE ENGINE IS HOT OR OVERHEATING. Check your car's owner's manual for specific details.
nothing wrong, it just stays on to help cool the radiator down.
The radiator is used to cool down the coolant (water plus antifreeze etc) which in turn is used to circulate the engine and prevent it overheating.
You don't need to keep your engine cool, Your car has a radiator system that will pump water/coolant to keep your engine cool. If you're engine is overheating, have someone who knows what they are looking for pinpoint the cause of the problem.
Low coolant?Cooling fan not working?Radiator air flow restricted?Radiator clogged?Water pump not working properly?Radiator cap defective?
possible radiator resrtiction
It is normal for a temperature light to come on in the VW Jetta when the car is started. If the light stays on, it is probably an early warning that there is something wrong with the radiator. The car may be overheating right away when started because there is no fluid in the radiator, or there is a fluid leak somewhere in the system.
Check the fan clutch, it may not be working properly.
Bad thermostat. It's usually a 5 dollar part but about 200 bucks in labor, unless you can do it yourself.