5 Signs of bad viscous fan

5 Signs of bad viscous fan

More often abbreviated as Viscous fan, Viscous Fan Clutch or Viscous Fan Coupling is a radiator fan component that uses oil to regulate fan rotation power. An engine drives the Viscous fan, so the Viscous fan rotation is very dependent on the engine speed.

When the outside temperature and engine temperature are cold, a slip will occur inside the Viscous fan. This slip condition causes the fan speed to be lower than the engine speed. Likewise, when the engine's temperature is hot, the Viscous fan will engage and stick together, so the Viscous fan rotation will also be faster following the engine rotation.

Symptoms of bad viscous fan

When the Viscous fan is going bad, the engine will easily overheat due to the lack of cooling that occurs in the radiator. The effect is that the engine may be broken down due to excessive overheating, which can cost more expensive repairs.

So how do we know the signs of a bad Viscous fan clutch? In addition to the overheats that occur in the engine, we can check the Viscous fan's condition to identify the Viscous fan is damaged or not. Here are the signs of a bad Viscous fan clutch that we know.



1. There is a crack in the Viscous fan fastening bolt

Cracks in the Viscous fan bolts are the first sign of a bad Viscous fan clutch. The condition where the fastening bolt is cracked can cause the Viscous fan's oil to seep and leak out.

As a result, the Viscous fan rotation becomes weak, and the engine temperature will increase and overheat due to reduced wind from the Viscous fan, which is needed by the radiator to cooling down the coolant temperature.



2. Oil seepage around the Viscous fan

The next thing that can be a sign of a bad Viscous fan is oil seepage around the Viscous fan. This oil seepage is sometimes just sticky dust that forms like a liquid stain around the Viscous fan.

Oil seepage on the Viscous fan indicates the lack of oil volume in the Viscous fan itself. As a result, the Viscous fan's rotation can become weak and cannot keep up with temperature changes that occur in the engine.



3. The Viscous fan rotation feels weak when rotated by hand

The next sign of a bad Viscous fan is that the Viscous fan rotation will feel weak and light when turned by hand. A good and regular Viscous fan will have more resistance and feel heavier when turned by hand.

If the Viscous fan is easy and lightly rotated by hand, the Viscous fan is going bad.

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4. When the engine is running, the Viscous fan rotates very slowly

The next sign of a bad Viscous fan is when the Viscous fan rotation becomes very slow compared to the engine rotation. As a result, the cooling process of coolant water on the radiator is disturbed, and the cooling that is carried out in the radiator is also not optimal.

We can see it from the Viscous fan's wind gusts, which are less than usual either when the engine rpm is idle or accelerating. It also happens when the engine is at a hot temperature.



5. The Viscous fan continues to rotate when the engine is turned off

The last sign of a bad Viscous fan that we know is that the Viscous fan continues to rotate when the engine is turned off. The Viscous fan that continues to rotate indicates that the Viscous fan's oil is no longer working correctly.

The result can be seen when the engine is turned off. This Viscous fan is still spinning for a long time until it finally stops by itself.

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