What causes a radiator fan to run constantly?

Bugs, dirt and other materials can cause radiators to become blocked up, detracting from their performance. This results in too much heat and the fans run to keep the radiator cooled. If a radiator gets too hot, it can crack, which is very bad news for your car, so it is a good idea to check this option first.

Why does my engine fan keep running?

It’s normal for some vehicles to have a fan run for a few minutes after the car is shut off, generally to keep the engine cool. However, if the fan is running for an extended period, the fan itself can become damaged due to overuse. It’s possible you may have a module or relay failing in your car.

Why won’t my cooling fan shut off?

The most common reason that your Air Conditioner fan won’t turn off is because a stuck relay keeping the circuit closed. Double-check the thermostat and make sure the fan is not set to ON, and that it still runs when switching it to AUTO or OFF (if your thermostat has an OFF setting).

How do I know if my radiator fan relay is bad?

One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. If you notice that your engine is running at higher temperatures than normal, that may be a sign that the relay is not functioning properly.

Should engine fan run all time?

An electric fan SHOULD NOT run all the time. A mechanical fan WILL spin as long as the engine is running, but it will only ‘lock up’ when needed. To avoid a further rise of temperature, the fan induces air flow. The fan turning on is normal and a consequence of the hot coolant, not a cause.

What fuse controls the radiator fan?

The cooling fan relay is normally located in either the underhood fuse and relay center or mounted to the electric fan assembly behind the radiator.

What causes a VW Passat to overheat?

My 4-cylinder turbo VW passat overheats very quickly when the cap is tight the coolant reservoir; not when the cap is loose enough to vent and prevent pressure from building up. Car has 70K miles, early 2001 model. 1. Small leak in radiator noted by dealer in May 2007, when doing service, including cooling system. Dealer says reapir can wait.

Why is the coolant not flowing in my Passat?

Incompatible mixes can gel and corrode . Your problem may be due to a plastic water pump impeller failing resulting in no circulation . the water pump’s plastic impeller cracked at the bushing where it connects to the shaft. At idle speed and low pressure, the impeller spins and coolant flows.

Why is the radiator fan on my car not working?

When the thermostat in front of the engine detects that the engine reaches a dangerous temperature, the radiator then kicks in by releasing a mixture of water and coolant to quickly cool down the engine. There is a sensor on the bottom passenger side of the radiator. It does the job of taking notes of coolant temperature.

What are the symptoms of a bad cooling fan resistor?

Another symptom of a potential problem with the cooling fan resistor is cooling fans that stay on at all times. If the resistor shorts or fails, it can cause the cooling fans to stay on even when they are not supposed to.

Why does my Jetta not have a cooling fan?

Simply the engine is not hot enough to turn on the cooling fan, its not hot enough outside, you are driving getting plenty of air flow through the grille to keep things cool without the assistance of the fan. Its possible that you have no problem at all. Was this answer helpful? I got a 2002 Jetta the cooling fans don’t turn on .

Why are the cooling fans not working on my car?

1. Engine running hot 2. Cooling fans do not function 3. Cooling fans stay on at all times Average rating from 129,472 customers who received a Vehicle Engine Cooling Inspection. Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool.

What are the symptoms of a bad cooling fan relay?

1. Engine running hot One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. If you notice that your engine is running at higher temperatures than normal, that may be a sign that the relay is not functioning properly.

How does a radiator fan work when the AC is on?

The electric radiator cooling fan assembly is controlled by a thermoswitch located in the side of the radiator. At higher coolant temperatures, the switch closes to start the cooling fans. Any time the coolant temperature rises to higher than normal levels, the fan will start and continue to run until coolant temperature returns to a normal range.